Tuning up the 454

[ClydesdaleKevin]

So, even though the coach is running awesomely, I'm giving her a tune up this week.  I was also ready to replace anything that needed replacing, like belts, hoses, plug wires, etc.  And I was very pleasantly surprised to find that a previous owner, probably the owner BEFORE the one we bought it from (who fixed everything with duct tape!) did a very awesome and thorough job not too many years ago replacing all the belts and hoses and plug wires and whatnot.  Even the fan clutch appears to be almost brand new!  The hoses are definately almost new, and still have the NAPA tags and stickers on them.  The belts still have the painted on labels on them, although I do need to tighten them a little, but no dryrot or cracks or anything on them.  And the plug wires are in excellent condition, 8mm red heavy duty wires, with built-in metal heat shrouds over the boots, and professionally done, still in the original looms.  Provided they all come off the spark plugs without disintegrating, and they still appear soft and pliable, then I won't replace those either.  I also found out why my coach sounds like a muscle car...that same p/o put on what appears to be a full Banks header system.  No wonder I get decent gas mileage!

So, it looks like all I have to do is replace the spark plugs...454s like the cheap stock spark plugs best, by the way...replace the cap and rotor, tighten the belts, change the oil and oil filter, change the fuel filter and air filter, I'm going to go ahead and replace the PCV valve and other little filters that go with the primative emissions system on this thing, and then regrease all the fittings on the chassis.  I should probably check the front brake pads and replace those if necessary too, but I just did them last year, and the rears were fine...but we tow a lot of weight, so I'll check em.

I'm not going to mess with the timing right now, as I don't have a timing light, and its running fine.

Then its replace the headlight switch and the ignition switch, check the tranny, brake, and p/s fluids, and we're ready for our winter boondocking adventures...woooooo hoooooo!!!

Now, if the new grill only gets here in time....grrrrrrrrrrrrrr...stupid place said they had it in stock, and the RV mount is apparently backordered, so we might not get it in time for Thanksgiving at my sis's place.  Which means we'll have to skip Thanksgiving dinner with the relatives, and wait here at the campground for it to get here.  Ah well.

Back to work I go!

Kev

[ClydesdaleKevin]

I got my friend Craig to come over and start drilling holes on the catapults, since it was raining all day, and that gave me a chance to run to Auto Zone and get the parts I needed for the tuneup, oil change, and the dash switches.  I decided to go with an MSD distributor cap and rotor.

Then I decided to attack the dashboard first, so that is pretty much all I got done yesterday in the rain.  It ended up being way more involved getting everything in the dash working correctly, since I had to fabricate brackets and hold downs for the heater/AC selector button cluster and cable.  It works now though, perfectly.  Yay!  I don't have to shut off or turn on the heat from the engine compartment anymore, I can do it from the dash...wooohooooo!

Then I replaced the headlight switch.  Very easy to do, and they even gave me the right part.  Once it was all plugged in, it works great now.  No more dash lights and marker lights mysteriously going out by themselves.  There is another dash light dimmer switch for all the accessory lights on our dash, which never worked before.  Turns out it had a loose...fallen off...ground wire, and now all those little lights work too.

The ignition switch gave me some problems.  Its an in-dash switch, but the key cylinder didn't want to come out of it for nothing!  I turned the key to the left and depressed the little sping inside, and the instructions say to keep turning it to the left and pull outward, and it will come out...not!  I finally got so frustrated with it that I grabbed the key with vice grips, and practically ripped the cylinder out...I had a new one anyway...lol!  Then the switch itself was fairly easy to get out, though its hard to get to or see.  I had to remove one of the dash air vents to see what I was doing, but it went fairly smoothly and works great.

By now it was around 4:30, so I still had some time.  So I decided to replace the cap and rotor, and fairly straightforward and easy job, right?  Hmmmmmmmmmmmmmmm.  The MSD cap comes with 2 little spring loaded rotor button/bushings.  One is for stock, and one is for high performance.  I went with the stock one.  Then it was time to remove my old cap and rotor. 

I can't believe the Nautilus was still running, nevermind as well as she was running!  Geese louise!  After I removed the cap, I removed the coil from the cap, and that is when I noticed that the rotor button/bushing was gone!  And instead of a little hole in the bottom of the cap, it was a great big burn hole the size of a nickle.  All that was left of the bushing was the spring, and that was just floating around loose.  What was left of the button part was rattling around on top of the rotor, the top of which was also burned badly and pitted.  So apparently, the coil was arcing to the rotor, and still ran the 454!  Ye gads!  The bottom of the coil looked all pitted as well, but I cleaned up the carbon on it and was going to reuse it, when I noticed that the brand new MSD cap had a crack in it right where the rotor button is supposed to go through it, and that one of the posts that connects to a spark plug wire was almost broken right off.  Really? 

So I called the Autozone I went to, and the one I bought was the last one in stock, but they found me another one at another local store, so I off I went, in the storm, to exchange it.  They gave me the new one, so while I was there I decided to get a new coil, and not risk the other one being damaged by the heat and sparks that had caused the demise of the old cap and rotor.

Back home I get, and install everything.  Then I hooked up all the spark plug wires...I labeled them before I took them off...and fired up the engine...VROOOOM!!!  Purring like a kitten...but then, she was purring like a kitten even with the bad cap and rotor. 

I have noticed lately some power loss up hills, especially long pulls, but I thought maybe I was imagining it.  Gas mileage seemed to be down too.  I wonder if that was why?

Okay...the rest of the tuneup and oil change has to wait till next week.  Gotta make the donuts!...I mean...catapults!

Kev

[Oz]

"VROOOOOM!"  is the most wonderful sound in classic RVing - 

[ClydesdaleKevin]

So another simple project turned into a long and major project, but don't they always?

The first thing I did today was change out the PCV filter and the fuel filter in the carburator.  That went smoothly, although getting the heat riser tube back in place after removing the air cleaner housing was a bit of a challenge.  That paper/foil hose just didn't want to bend in the tight clearances, but I finally got it just right.

Next it was time to tighten the 3 belts.  The serpentine was the hardest, since it was hard to reach the pivot bolt on the alternator, so I did that one first and it went smoothly.  The other 2 went easy, although the pivot bolt on the AC compressor was impossible to get a wrench on.  There is a fat wire cluster in front of the bolt side, and the belt is in front of the nut side, and there is no clearance at all to turn a wrench.  So I squeezed a socket on the bolt side past the wire cluster, and used a 1/4 drive socket on the nut side by pushing the belt out of the way to get to it.  It worked!  The air pump belt was the very easiest.

Okay, the belts were done, now on to the spark plugs. 

This is where it all went down hill.

I gapped the plugs...I used AC Delco R44Ts, and the gap called for was .045.  Wow!  They don't make it easy to reach the plugs, and they go into the head at a very wierd angle...and it seemed that each angle was just a little different than the others.  There are heat shields everywhere in the way, and body supports, one of which was right in front of one of the plug boots.  The Banks header pipes didn't get in the way too much, but they certainly contributed to the clearance problems.  2 plugs broke on the way out because of the long extention I had to use and the inability to use 2 hands on some of them, which cause a side load which broke the insulators.  They came out though, and all the plugs looked good...no oil, the right color, no build up...except one, number 8 spark plug was soaked in gas.  The new plugs went in fairly easily, started by hand, and then I sacrificed some blood and skin making sure I could use 2 hands on the hard ones so the side load would be eliminated.  But that brings me to what really turned this into a project.  Number 8 was the first plug wire I pulled to change out the plug, and it fell apart in my hands.  None of the others came apart, but some seemed brittle and I decided to change them all out.  Easy, right?

Okay, I'm dirty, I've got leaves and twigs and grease in my hair, and I figure while I'm under the rig I'll track down the mysterious fuel filter along the frame rail on the passenger side that the manual said is supposed to be there.  I found it right away!  And, much to my delight, there is an access hatch to get to it in the front passenger side compartment.  Sweet!  Well, it was sweet for a minute anyway.  It was a metal canister filter that said Napa Gold, but the cross-reference numbers were illegible, so I left it in place.  Should be easy to match up, right?  1/2 inch inlet and outlet.  Easy, right?

Off I go to the auto parts store.  First I went to Autozone.  While I was there I picked up the PCV filter, the fuel filter they swore was the right one, a tube of grease so I don't run out greasing the fittings tomorrow, and a can of carb cleaner to clean up the carb linkage and all that after the oil change.  Then we start looking for the plug wires.

This is the heart of Nascar down here near Charlotte.  How hard could it be to find a set of plug wires for a 454 in the land of race cars and performance vehicles?

Autozone looked them up for an 89 P30 chassis...none in stock.  None in stock in any store for miles and miles and none at the hub.  It would take 2-3 days to get them in, probably longer if they didn't come in by Thanksgiving.  We looked at every wire they had for the 454, all years, high performance and otherwise...nada.  The problem they were having was that the boots on the ones they had weren't long enough to fit in the metal heat sheild tubes that go over the boots, and I sure wasn't gonna leave them off!

So I skip down to Advanced Auto.  Same deal!  None in stock anywhere, none in the hub, I'll be lucky to get them by Friday.

Off to O'Riley's.  Same deal.  Really?  This is Nascar county, for the gods sake!  Wait,  they crossreferenced a bit and they had a set...a cheap crappy set...with long enough boots in stock.  I don't want cheap crappy wires, but I told them I'd be back if Napa didn't have the wires I wanted...gotta have wires, so I figured worse case scenario I'd use them, and then order the right good wires in Louisiana, our first stop on vacation where we'll stay a while.

Off to Napa.

Napa was the most helpful.  The exact wires were out of stock, same deal as everywhere else, and they could probably get them in on Friday, the day we are leaving.  But they called all the local speed and performance shops for me...and none of them had the right one either!!!  The could fabricate any wire I wanted, but for some reason none of them had long boots for the metal heat shields...really?  I guess they don't use them in race cars!

They cross-referenced every application they had in stock that had long boots that would fit the 454...and they had one...and they were good wires!  And it was the last box they opened too...figures.  I hate Murphy and his laws!

The wires are blue Belden Max, 8mm.  Very good wires with a lifetime warranty.  The boots were straight instead of angled, and they said they couldn't guarantee exact wire length, but they fit the same year Suburban with the 454, and the boots were long enough for the heat shield.  Sold!

Since the Napa was right next door to Northern Tools, I went in and got the solar trickle charger I wanted to get for the Jeep (on sale for 10 bucks instead of 20), and the 12 volt transfer pump I needed for boondocking, so at least I don't have to make another time consuming road trip before we leave.  I just put in a brand new Interstate battery in the Jeep, but wanted the trickle charger because I noticed on long trips that the battery would drain using the Brake Buddy.  Not a biggie on short trips, but a 1000 miles or more could cause the battery to be so dead I had to jump it.  Might be because the battery was bad, might be because the Brake Buddy compressor draws voltage when you brake and there was nothing recharging the battery.  The new battery and the solar charger should solve that issue.  I picked up the 12 volt transfer pump because you can't fill our freshwater tank with anything but a hose.  City water and freshwater fill is the same hose fitting.  You turn a valve and a hose under pressure fills the freshwater tank.  You can't dump gallon jugs in, and we are going to do a lot of desert boondocking in places with no water.  The 12 volt transfer pump already has hose fittings on it, and it pumps at 5 gpm, self priming.  For 40 bucks, way better than modifying a SureFlo pump, which only flow at 2.5gpm for the cheapest ones, which are at least 90 bucks.  Anyhow, I'm getting sidetracked.  Back to the wires!

Maybe its because this is Racecar Nascar country that 454 wires are scarce?  Supply and demand?  But it ate up hours out of my day!!!   

Anyhow, I get back to camp and its already 4:30 PM.  And I decided to change the fuel filter first.  And it was the wrong one!  Grrrrrrrrrrrrrrrrr!!!  The inlet and outlet was 3/8.  I need 1/2"!!!!  Back to the auto store tomorrow!

So I put on the new PCV filter and new air filter, close it all up, and get back to the spark plug wires.

Of course, I'm doing one wire at a time, and I'm not sure if the wire lengths are going to be right to fit in the looms and be routed factory without hitting anything hot or being up against something that can abrade them.  So I lay the new wires out by length, and make a mental note of which wires seem to be the longest and the shortest.

I got pretty lucky.  The passenger side wires were pretty close.  3 of the 4 fit exact,  and the 3rd I had to bring up under a hose across the valve cover, but valve covers stay relatively cool.  The important part is that all the wires are way out of the way of the manifold and hot heat pump emission tubes.  The driver's side was more challenging.  Again, 3 of the 4 were able to be left in the factory looms, but I had to get creative with zip ties so none of the wires would hit the manifold or the air pump tubes, or the linkage rod to the transmission.  The last wire...the front most plug on the driver's side...had to be routed past the throttle and cruise control linkages, over the valve covers, and then zip tied to make sure it wouldn't touch anything...but the end result was a brand new set of wires...good wires with a lifetime warranty...routed neatly and intelligently and not touching anything that could damage them.

Then it was time to start the engine.

VROOOOOOOM!!!

You are absolutely correct, Mark!  The most lovely sound ever, especially in classic and vintage RVing!

No skips, just perfect engine sound.  Smooth as silk.  This thing doesn't even make any valve noise, and its got almost 100k on the motor. 

I let it warm up and watched the belts.  I lifted the air cleaner housing to make sure that the fittings to the carburator filter weren't leaking, and all was well...but that made the paper/foil hose fall off, and I had to ease it back again into place.  Ah well. 

So, tomorrow, its oil filter and oil change, grease all the fittings, check the diff fluid which has never been low so far, top off the brake fluid and check the front brake pads which should be good but need to be checked, top off the tranny and P/S fluids, check the tire pressures and new air bag pressures, and when the engine is warm I need to spray carb cleaner down it while running to clean up the butterfly linkages and whatnot.  Today I already vacummed out all the acorns and chipmonk nests on the intake manifold and cleaned up the outer linkages.

And Patti did something today that at first ticked me off...and then made me smile and love the most awesome woman and wife ever even more!  While I was out hunting down wires and whatnot, she flagged down the mobile RV repair guy and had him troubleshoot our furnace, which suddenly stopped working.  I was going to do it myself to save money, but she knew I was already stressed out and out of time and under the gun.  He actually removed the furnace and took it home, and said he was going to clean it out and blow it out and was pretty sure it was some valve, because the sail switch seemed to be functioning perfectly.  There were a couple of wasp nests, but nothing that should have caused a problem.  I was mad cuz its gonna cost me 200 bucks!  But its one less thing I have to do, and Patti thought it was worth it.  She's awesome!!!

So, after I finish with the rig tomorrow, I have to cut out, drill, and sand all my trebuchet and ballista parts for the Arizona show, and then return the new table saw that started making the same sound the last one did right before it caught on fire!  I'll get the new fuel filter while I'm out doing the return.

It wasn't supposed to rain here until tomorrow night...but its raining now, darnit!  I was going to take down our display tent tomorrow morning and pack it away, but I can't pack it wet.  The next show is February, and it will mildew by then. 

Everything is always weather dependent with us...but at least the oil change and all that isn't!  Its UNDER the rig!  Out of the rain!

We are leaving here Friday night or Saturday morning, so everything has to be done by then, and of course Thurday is TURKEY DAY!!!!  We are have quite the shindig here! 

Okay, I'm digressing WAY too much again.

The tune-up and oil change and whatnot will continue tomorrow!

Kev

[tiinytina]

From experience this summer... she'd had a total tune up but we didn't replace the ignition coil and ignition control module under the cap.... and... W%.... also make sure to use the grease supplied under the ignition control module... 

Tina

[ClydesdaleKevin]

Hmmmmmm...I didn't think about getting a new ignition control module.  Maybe I'll pick one up just in case.  Anyhow, the only thing I got done on the rest of the tune-up/oil change yesterday was picking up the right fuel filter at Napa, and then returning the wrong one to Autozone.  The rest of the day was dominated by taking down our shop tent while it was dry and before it could stop raining, cutting out a whole bunch of catapult parts, and then returning the table saw we just bought that already started to sound like the last one did right before it caught fire.  While I was out was when I got all the rest of the stuff we needed, including more TurtleWax wash and wax, since I'm gonna wash the rig right before we pull out...she hasn't had a bath since May.

Today the oil change happens, the fuel filter goes in, all the fittings get greased, all the fluids get checked and topped off, the air pressures get checked, the front brake pads get checked, and then the great packdown begins.

Vacation is almost here!

Kev

[ClydesdaleKevin]

So all the tuneup stuff and all that got done yesterday, except the air pressures, which I'll check tomorrow...cuz its turkey day today!

The first thing I did was put in the new fuel filter, and then started the engine to let it warm up and to make sure the fuel filter didn't leak.  While the engine was warming up I got all my tools ready and the oil and filter on deck, and secured the hatch over the fuel filter.  Then it was a simple oil and filter change.  The fact that our campsite slopes forward makes doing anything up front a cinch, since the RV is parked with its front wheels up on Linx blocks. 

Then it was time to grease all the fittings.  There are a LOT of fittings on the P30 chassis, and not all of them are easy to get to, but they all got wiped down and greased.  Of course, as Murphy's law would have it, the grease gun ran out of grease on the very LAST rearmost U-joint fitting, and since that was at the back of the coach I had as much room to move as a coffin...Patti handed me the new tube of grease from outside the coach, and I managed to refill the gun in the confined space and grease that last fitting, then wiggle back even further under the rear axle and check the diff fluid, which was fine.  Then it was back crawl all the way out to the front, wash all the grease off my hands with GoJo Orange, and take off my old Navy coveralls which I save for just such occasions.

Back under the coach I go to check the brake fluid with clean hands, and to feel the brake pads in the front calipers...all good!  They really don't make it easy to check the brake fluid in this thing either.  You can't see it, you can barely get a screw driver in there to remove the bale wires, and you have to dip your clean finger in there to feel the fluid level.  It was all good though...yay!

Radiator fluid was perfect, washer fluid almost full, power steering right where its supposed to be cold...alright!  I'll have to check the transmission fluid when I drive it out to the parking lot Friday afternoon, since it won't warm up enough to check just sitting at the campsite, no matter how long I run the engine, but I'll check it then.  Then Saturday morning we roll outta here!  And the great adventure will begin!

Kev

[ClydesdaleKevin]

So the last leg of our journey so far, I noticed a distinct decrease in power up hills, my gas mileage went back down to barely 7mpg, and its pretty much flat here in Louisiana, and acceleration seemed boggy.

Any ideas?

Could a dying ignition control module, one of the things I didn't replace during the tune up, cause this?

The symptoms also seem to line up with a possible stuck EGR valve.  Any way to test the valve in place, or is it something I have to remove to check, and then replace with new since I removed it anyway and the part is only 35 bucks?

Other things I thought it could be was a possible dead or dying electric fuel pump in the gas tank, which I'll check today...just turn the key and listen for a hum at the tank...that would at least let me know if the pump is getting voltage, although to really test it I'll have to wait for it to stop raining, take off a fuel line, let Patti turn the key, and see if fuel is flowing.  But I really don't think that is it, since I would imagine the symptoms would be more like vapor lock with just the front mechanical fuel pump working.  It still has lots of power, just not the power or MPG it did, and there isn't any hesistation or...that vapor lock stall, if you know what I mean.

I was also thinking maybe one of my new spark plug wires might have come loose, or that maybe even one of the spark plugs themselves came loose...it was really hard to torque a couple of them down, and I might not have tightened them all down enough for fear of braking them.  Thats also something I'll check when it stops raining.

I'm also thinking that maybe I should have went with the low resistance rotor button?  Sometimes we are taching up long pulls at 3 grand.  Maybe the OEM button can't handle it?  That's something I'll also pull and check soon, make sure its not melting the cap like the old one!

The only other thing I can think of is maybe a vacuum line came loose.  Whats the best way to check manifold vacuum?  Just pull a hose and feel for vacuum?  One of these days I'll install a guage, but for now, whats a quick way to check it?

Any other ideas?  We still have almost 2000 miles to go...and then some.  I want it running perfect.

Kev

[tiinytina]

All times that we have lost engine power in Gone it has always come down to 1-2 bad wires, melting etc right at the plug end...  When we first got the banks on her and a full tune up I didn't even have to touch the gas and she was creeping forward.. now I have to put on the gas.... And we have the heat caps on the plugs...

We also know from vacuum testing that we have a bad EGR valve that is not holding vacuum.. but were told that this is only emissions control stuff and shouldn't effect mileage... but... EGR valve is like $350 or something when I tried looking it up... we replaced a few vac tubes that were cracked from age....

We put on a new ignition coil and control module but that has not effected or increased mileage or power. Rotor and cap are standard and new. plugs are Champion.  We have high grade silicone wires on her but as stated keep finding melted right up near the plug. 

We are averaging 7.4 it seems no matter what we do.. with exceptions for driving weather, genny and we do not have a toad.  We sit no fresh water, empty water tanks at 13,800Lb...

Tina

[DaveVA78Chieftain]

This is one those imes you need the proper tools.  Vacuum gauge and a vacuum pump at a minimum.  A automotive test meter with a tach would be very helpful.  Otherwise you have to earball the RPM changes.

http://www.autozone.com/autozone/repairinfo/common/repairInfoMain.jsp?targetPage=productsHowToInspect&leftNavPage=productsHowTo&pageId=%090996b43f80a01291&subtitle=test

The nice part is tools like this always come in handy.

Dave

[ClydesdaleKevin]

Thanks Dave!  That was really informative.  I actually have a vacuum pump that supposedly also doubles as a vacuum guage, although I've never used it that way.  I mostly bought it a few years ago to bleed the brake lines on the Ark, since it does that too.  Paid almost a hundred bucks for it...and fortunately kept it with the rest of my tools.  The tach on the dash seems pretty accurate, so that's a plus.

I'll check out the valve this week and let ya'll know what I determine.  Today we're going to Nawlins, as they say down here.

Kev

[ClydesdaleKevin]

Alrighty then...

The spark plug wires are still perfect, just as I loomed them.

The spark plugs are all tight...they were tight and didn't loosen.

The EGR valve tests normal...opens and shuts under vacuum.

Vacuum level going to the EGR valve is normal...4 hg at 2000 rpm, 0 at idle.

Manifold vacuum tests perfect at idle...19-21 hg.  Well, almost perfect...the needle vibrates back and forth between 19-21.  According to the manual that came with the vacumm pump, that indicates the carburator running a little rich or a little lean, although the fluctuation is 3 hg, not the 4-5 the manual said indicates a problem.  No way to adjust this carburator though...GMC riveted the choke adjustment shut, instead of screws like the carb on Excalibur.  All other screws are sealed over, except the idle screw, and the screw adjustment that determines when the secondaries open.

The electric fuel pump is functioning exactly as its supposed to.

The rotor button shows no sign of heat damage, which indicates that its not the culprit.

So...that narrows it down to the ignition control module, or the pickup coil, both of which, according to Autozone's website, can cause:

"When not replaced, vehicle may experience no start, hard start, intermittent engine shut down, misfire, engine cut out, excessive fuel consumption, CEL illumination and/or failed emission test."  for the pickup coil.

"When not replaced, vehicle could experience no- or hard start, long crank time, misfire, lack of power, inconsistent transmission shift points, spark plug fouling, catalytic converter failure, poor fuel economy or CEL/MIL illumination." for the ignition control module.

So, for a grand total of 49.00, I can replace both, eliminate them from the equation, and see what happens.  So I'm about to go to Autozone for the parts.  At least I'll have spares if neither one turns out to be the culprit.  Seems to me, logically, that since the old distributor cap had a hole burned through it and a missing rotor button, then it stands to reason that other parts of the distributor electrical system may have been damaged.  I already replaced the cap, rotor, and wires.  Might as well replace the last 2 parts as well.

If this doesn't solve the issue, then it would seem the carburator is the culprit, or else some other part of the horribly intricate emissions system is causing the issue.  This thing has more vacuum lines than Carter has liver pills!  And I checked all of the lines, and they seem to be going to the right places, and none are crusty or damaged. 

If replacing these parts doesn't completely solve the issue, then a new Edlebrock carb is in the future.  Not until after the AZ Renfaire starts though, since they, with all thier adapter plates and whatnot, are expensive!  And if I shell out the cash for a new carb, then all that emissions crap is coming off too, and I'm going to simplify the vacuum system.  No more air pumps...yes, there are 2...no more million and one valves and hoses and crap everywhere.  I'll keep the EGR setup, since its simple, but all the other stuff has to go.

So...any other ideas what might cause these conditions if the parts I'm going to install don't do the trick? 

Kev

[ClydesdaleKevin]

Okay!  The new ignition control module is in.  I cleaned up the base where the old one was, coated the metal underside of the new one with the white grease that came with it, and it was an easy install. 

The pick-up coil?  :)rotflmao No way.  Not gonna do it.  There is no way I'm going to remove the distributor and essentially disassemble the whole thing to replace it.  When I remove the distributor its going to be to replaced with a high performance one someday.  I should have researched how to remove and replace it BEFORE going to Autozone, but I didn't.  So, next time I go to Autozone, back it goes and I'll get my whole 22 bucks back.

After installing the new ignition control module and cap/rotor/coil/wires, I started the engine to make sure all was well.  It could be my imagination...probably is...but it sounds better.  Started faster than it has in a while, and seemed to run smoother.  The next leg of the journey will tell!

new MSD cap, and new 8mm Belden wires

Getting there!

Kev

[DaveVA78Chieftain]

Vacuum leaks can be a source of pain.  Check for:

Cracked hoses

AC/Heater vacuum operation hose leaks

Fuel Vapor Vacuum canister leaks (Bottom right corner of your hose drawing picture)

Fuel vapor return hose condition (canister to fuel tank)

Spray wd-40 at base of carb (engine running and warmed up) all around it looking for vacuum leaks (gasket or worn throttle shaft).  Engine speed will change if a leak is present.  Some people use butane lighter or propane torch (unlit) to do this.  I never liked the idea of spraying combustionable gas at a engine.   

Pull cap off distributor then use your hand vacuum pump to verify the vacuum advance mechanism operates (varies timing based on ported engine vacuum by rotating the hall sensor pickup mounting plate).  Vacuum advance used to provide maximum fuel economy.   While cap is off, make sure centrifugal advance mechanism (directly under rotor) moves back and forth freely and springs return it to base position.  Centrifugal advance used to advance timing to provide maximum power.

All that is common stuff through the carburator years.  For all the other "stuff" you would need to look at the  chassis manual to derive testing methods.

Dave   

[Froggy1936]

Hi Kev, The tip to check the vacume advance and centrifical advance weights is a very good one as they are both common problems especially the weights getting stuck due to rust and electrical current (ground) passing thru them. Frank

[ClydesdaleKevin]

Thanks guys.  That was one of the things I checked with the vacuum pump, and it moves under vacuum...and the weights are free moving and held nicely by the springs.

Hopefully it will run better now.  A lot of the reading I did indicates that when a coil goes bad, it can damage the ICM, and vice versa.

Kev

[ClydesdaleKevin]

It makes the most sense to post this here in this thread to keep it all in one place.  I'm tuning up the Holiday Rambler again and was looking for the spark plug gap.  The O'Reilly's that sold me the new spark plugs (AC/Delco R44Ts) insists that the gap is supposed to be .035.  But I remembered (verified here) that I had always gapped them at .045 before.  I am replacing the cap and rotor with an Accel performance setup, and the coil with an Accel high voltage super coil.  From the hot rod forums, I am seeing that most of the folks that use high voltage coils up their spark gap from .035 to .042-.045.  Any thoughts on that anyone?  I'm thinking of just gapping them at .045 like I did before since it runs fine.  Any advantage to running them at a smaller gap?  Thanks!  Kev

[DRMousseau]

I think you might be surprised at the difference that little gap adjustment will make. Surprisingly, many engines were designed around the sparkplugs available. And the plug manufactures suggested gap isn't quite what the vehicle manufacture suggests, because the vehicle manufacture want's you to be trouble free. And vehicle specs are what the books list at suppliers. The smaller gap ensures a spark every time thru various conditions of fouling and age. All else being the same, the larger gap generally provides better and more efficient ignition, but will require a bit more frequent servicing and greatly depends on other parts in the system being in top condition. Given your cap and coil improvements, you should have great dependability and long life with .045 spark gap. Watch engine temps a bit, but it should be no real problem.

I'm anxious to see your thrill in this tiny change!!!

[Froggy1936]

Hi Kev Ready for Christmas ? How is everybody doing ?  On Plugs I have set every plug for any veh or engine @ 35 Thousandths since 1950 never had a problem with any of them Remember the gap grows with wear so Also i dont remember seeing any gapped less than that ,  W% Frank  MERRY CHRISTMAS  from FRANK & LOUIE

[ClydesdaleKevin]

I went with .045 since it is what I've been running it at since I bought it.  Should be fine.

Kev

[ClydesdaleKevin]

By the way...Belden wires suck.  I put those blue ones on in late 2011.  And they all kept breaking at the boot when I tried to remove them today.  Supposedly lifetime warranty (no receipt) and those boots are supposed to be for high heat.  But even inside the metal heat shields they deteriorated.  So I am replacing all the wires, one at a time, with Accel high performance yellow ones.  Yay when a simple projects turns into an all day nightmare and spills over into the next day...lol!

Kev

[Rickf1985]

Kev, 045 should be fine with HEI but be sure when you open them up that the center electrode stays flat across the round strap. When they are designed for .035 the ground strap is bent just right for that gap and when you open it up you will find that the rear of the ground strap is closer than the end is. This means that the spark will always arc off of the same spot and you will lose power much sooner than if the spark moves around on the post and ground.

[DRMousseau]

YES!!! Use care in those plug gaps!!! Since my long time favorite brand is now made in Mexico, the quality and precision has suffered DRAMATICALLY!!! Crooked, misaligned, and un-centered electrodes that look to be cut with a dull axe!!! UGH!!! I now use a brand of much better quality, as spark-plugs are pretty important.

I believe THOSE plugs you have are "pre-gapped" to AC/DELCO's specs of .040,... easy to understand why vehicle manufacture reduces it slightly, and why those "in-the-know" increase it slightly and watch them more closely.  FYI, I believe there's a variation of the same plug (R44TX?? for "Resistor xx Tapered tip eXtra gap") is spec at .050! For high-performance use, and often set at .055-.060!!!

[tarifachris]

Changed today the little fuel filter from the quadrajet... Looked like it was the original one!

I had to remove some emission stuff to have access to the filter. Since I was there I replaced the EGR Valve and a new
PCV Valve as well. Patched and replaced a bunch of vacuum lines and had to epoxy even some vacuum line couplers, because they
are not available anymore.

Engine runs smooth - or just for peace of mind...