odd starting, and running, then not, fuel filter??

JerryP · March 25, 2015, 01:53 PM

Started up the 89 Chieftain, ran fine, moved it so I could move another car.
left it running to charge the chassis battery, as it was dead.
after a few minutes I heard a slamming noise that sounded like the door slamming on the RV.
Went out, to check it, it was the engine backfiring
gave it some throttle, to clear it, and it died,
hard to start, and stumbled, and sputtered
only way I could get it started was full throttle, and then it dies after a second or so.
burping out a mist, and a long exhale is the best I can describe
I thought it was the fuel filter, or pump maybe,
I did pull the air cleaner to see if I had knocked a vacuum line off while moving the smog pumps.
All was good
Decided to track down the fuel filter, came in and did an internet search for its location, went out about 20 minutes later, started right up, and idled fine, drove fine.

I suspect this is early stage fuel filter clogging, My thought is that it just got its first fill up a couple weeks ago, and there is probably something in the filter now.

It is running fine now let it run about 20 minutes and still all good??

Anyone else have any ideas of other things to check??

circleD · March 25, 2015, 03:00 PM

If you have the quadra jet check the filter on the carb and the main filter. It could be a dirty carb jet, fuel issue such as water or junk floating around now that there's fuel in it, or a small tuning issue. Rick or Dave know more about the finer details. I replaced my fuel lines and carb and checked vac lines.

72-d24 · March 25, 2015, 03:39 PM

Sounds just like the symptoms ours gets when we run off the back tank (paperwork shows one tank was cleaned and coated; I suspect the front one. The back runs dirty). Ours has Edelbrock everything (carb, headers, exhaust). I make sure the rig is stocked with replacement fuel filters and we replace them freely (every few hundred miles). I suspect this isn't the best choice for the carb and engine.

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JerryP · March 25, 2015, 09:10 PM

Thanks guys,
Going to have to jack up the RV to find the fuel filter.
It is either too low, or I and am too big to fit under it

To me, it seems like text book fuel filter.
Temporary starvation, or lean condition
While poking around I did find a inflation stem, in the wheel well, for air shocks or something

But the 454 is not an engine I am completely familiar with.
Seems pretty much like giant version of any other GM engine I have owned though.

circleD · March 25, 2015, 09:43 PM

Here's the basics of the monster 454. They get hot. Can withstand a lot of abuse. Parts are easy to find. They WILL leak oil regardless. The exhaust flange is bad about leaking. But are very reliable. You'll get it my friend

TripleJ · March 26, 2015, 12:45 AM

To help with diagnosis, and to keep from getting too wild with the suggestions of what it MIGHT be, it would be helpful to have a rundown of what type of fuel system/carb you are running. Electric or mechanical pump, pressure regulator, type of carb or TBI even?

Also if you are running the factory HEI and when was the last tune up, etc...

JerryP · March 26, 2015, 01:07 AM

Quote from: TripleJ on March 26, 2015, 12:45 AM
To help with diagnosis, and to keep from getting too wild with the suggestions of what it MIGHT be, it would be helpful to have a rundown of what type of fuel system/carb you are running. Electric or mechanical pump, pressure regulator, type of carb or TBI even?

Also if you are running the factory HEI and when was the last tune up, etc...

I am running full stock whatever that is

Honestly, i do not know what the fuel pump situation is. Just learning as I go with the 454,
only had it 3 months or so, and it appears it was tuned up before I bought. Runs perfect, until this issue today, now it seems to be running perfect again
All I know is that I like it, I need to stuff one of them in my miata, but the miata engine may never wear out

Anyone have any idea what the plug in the upper right corner goes to?

? It appears to be homeless??

Rickf1985 · March 26, 2015, 07:03 AM

That plug may go to the thermal sensor on the air cleaner, but I think that is a spade type connector. Those type of connectors usually plug into another wire or directly into a sensor and are part of the engine and emissions control systems. When you pulled your AIR pumps did you pull any electrical parts and forgot about them? As far as you backfiring and shut down problem it "may" be a filter but the symptoms are screaming bad ignition coil. If you have never changed the fuel filters then do that since it needs to be done but if you still have the problem I would say the coil is going bad. If that is the case you don't want to be driving far because one of those times it will not start even after cooling down.

72-d24 · March 26, 2015, 11:09 AM

I reread your first post, which I must have read too quickly the first time through. Mine does not have all the same symptoms you describe. I only hear teeny tiny backfires, and only when she is cold and has sat for a while. She has no trouble starting, ever (I missed that you were having trouble starting). She looses power, like she is out of gas, when running off that back tank when the filter begins to get plugged. I switch to the forward tank and she runs fine. If I let the fuel filter get too plugged, she will sputter and die when I give her gas, as you describe.

Honestly, I gotta agree with some of these other suggestions. Loud backfiring after warming up, inability to start, and then starting up just fine when cooler could be fuel delivery issues, but I wouldn't rule out other possibilities.

What I hope you get from my post is: change the fuel filter, regardless. Keep extras and change it often, especially if the fuel that comes out is tainted in any way. I learned the hard way last summer when we couldn't figure out where the darn thing was located. Cost me a fuel pump and almost had me stuck a long ways from home.

JerryP · March 26, 2015, 12:45 PM

Quote from: Rickf1985 on March 26, 2015, 07:03 AM
That plug may go to the thermal sensor on the air cleaner, but I think that is a spade type connector. Those type of connectors usually plug into another wire or directly into a sensor and are part of the engine and emissions control systems. When you pulled your AIR pumps did you pull any electrical parts and forgot about them? As far as you backfiring and shut down problem it "may" be a filter but the symptoms are screaming bad ignition coil. If you have never changed the fuel filters then do that since it needs to be done but if you still have the problem I would say the coil is going bad. If that is the case you don't want to be driving far because one of those times it will not start even after cooling down.

Thanks for the input,
I agree,
The plug has no place to fit on the air cleaner, I am going to go back, and check the pollution stuff closer, must be it.
Agree on the coil
Old coils get hot, and act funny, then cool off and work fine again. Your comment on the coil, was my second thought, and my experience with bad coils say that would be the next thing to check.

The battery was dead, and I had used the aux button to start it,
Behavior was similar to a totally dead battery.

Alternator is working, and the battery is charging, but battery/alternator is number 3 on my possibility list.
I still may need to look at the battery /altenator, as I am not sure at what RPMs GM alternators start to actually charge. At one time Chryslers did not start charging until 1400 RPM.

Rickf1985 · March 26, 2015, 12:54 PM

The GM alternator is charging at idle, Not full charge but substantial charge. If the battery was totally then you can burn out the alternator trying to charge and battery that will not charge.

JerryP · March 26, 2015, 01:05 PM

Goes on the A.I.R. Pump, was not connected when I took it off, so I did not notice the plug.
thanks guys!!
Going to use the label maker to tag it.

074.jpg

TripleJ · March 26, 2015, 07:17 PM

Speaking to your original issue, it reminds me of trying to run an engine with a dying battery/bad alternator. Full fielding the alternator at idle might cause it to overheat and shutdown, then the engine would begin to die due to low battery voltage, stumbling/backfiring, etc

Typically a fuel filter does not cause issues at idle, then allow an engine to run under load. Then again, the little filter at the Qjet inlet has been known to cause strange fuel restriction problems...

Still change yoru filters, but look into battery/alternator issues too

JerryP · March 26, 2015, 10:56 PM

Been thinking about putting a float charger on the chassis battery.

tiinytina · March 27, 2015, 08:35 AM

Gone did this while driving... there is a connector on the side of the distributor that a bottom clip on the wiring harness had finally given out on, causing the misfires and backfires (which ended up blowing a larger hole in the manifold and blew the seam completely on one muffler so sounded like a tank for next 100 miles home). Zip ties to the rescue which are still there I think. LOL. she would start and run but then wallow and die, misfiring along the way until finally she just died all together. Just my 2 cents...
Tina

JerryP · March 27, 2015, 05:48 PM

Thanks, I will look into that.
Intermittent stuff is a pain, hopefully this is not going to be intermittent.