Engine won't start - almost no fuel to carburetor

[crenninger]

Hi All,
I (hope) I am an owner to be...
A friend is allowing us to use his Winnebago Itasca Sunflyer 1985 22Ft Chevy 454 Gas (with rear bunk bed) if we can get it to run! 
The RV has been parked for ~10 years, and has not been started for about 5 years.

I spent a day last sunday working on it, checked all the fluid - OK - and put in a new battery.

Then went onto trying to start, Last he remembered, it was smelling fuel when he ran it last.
Sure enough at the connection of the rear tank and auxiliary tank, the switch hoses were bad so for now I by passed the whole switch and got the rear tank directly connected to the front/engine fuel pump

Put ~5 gallons in the rear tank and started trying.
Amazing with little starting fluid the engine wants to run, but nothing else. No gas getting to the carb. With starting fluid the engine runs then dies.

I tried sucking up fuel on the main hose at the fuel pump, but nothing would come.
We sent compressed air backward to the tank and that surely works - so that line is not clogged.

Next we tried to hook up a gas can to the front fuel pump directly and tried to start.
the fuel pump would suck gas but barely any would show up at the carb. We even disconnected the fuel line intake at the carb and then tried the fuel pump and it was barely a little dribble of fuel coming out.

This seems to point to a bad fuel pump at the engine -
I am going there Saturday again to try to get it to run, and I am wondering what else I could get prepared for so I don't spend an other day running after parts.
We do see a little bit a fuel spitting out when we push the gas pedal in the main (smaller hole) in the carb - so I am hoping the carb and jets are not gunked up.

I think now the goal would be to make it run from a gas can, then check about gas from the rear tank to the front fuel pump

How much pressure should the fuel come out at the carb? strong?
We had about 1gallon of fuel from the gas can  go through the pump but we didn't see any of it at the carb, I am guessing it went through the return?

Any help, pointer welcome.
If anyone local has knowledge, I'd love to hear, I am in redwood city CA, the RV is in San Cruz-CA

Also I tried to find the P30 manual being referred in many post, but so far I am out of luck finding it.
Obviously we are trying to invest as little as possible in this until we know it's running properly.

thank you
christian

[Bigjohnk99]

Hi Christian

Look in the forum section under member articles.  I'm Still Lefty wrote a real nice piece on getting an old RV back on the road.

Good Luck

John

[007]

pick up an electric fuel pump, fuel line, clamps and some 14 gage wire hand hook directly to the carb from the gas can and see if it runs good that way till it's warmed up and you check for other problems , first place i'ld start. mark

[cosmic]

I'm thinking if that rear tank is all rusted to hell. then the second you go to suck gas up it it gets stuck with crap. this would explain why the compressed air makes its way back but not up.
a new mechanical fuel pump should cost ya 30 dollars or less at napa.
a plastic fuel fillter a dollar or two and then you can see whats getting sucked out of the tank.
good luck

[Froggy1936]

First, pictures would help a lot, second what kind of carburator . If its a Quadrajet it has an internal filter under the inlet fitting. As mentioned above clear plasic filters are a big help in seeing where you have fuel and if you have rust/dirt. Also you can move your can to a position above the carb and gravity feed the carb eliminating everything except the carb (make sure you have all fuel line outlets plugged or into a container ) in case it starts, pumps will move fuel ! Under normal conditions the pump wile cranking engine with a battery will put out approx a qt of fuel in 20 sec. Carburator cleaner is a better option for starting than starting fluid, also it may help with a gummed up carb (it is very flamable)  Frank  Also for a R/V sitting that long check tires for cracks .

[ClydesdaleKevin]

In 85, it should also have a factory electrical fuel pump, either in or near the gas tank.  Listen for humming with the ignition key on.

Also, there is a very small paper filter in the carburetor itself, where the fuel line attaches.  They are supposed to open up if they get clogged so the fuel can bypass the filter, but sometimes they don't and fuel can't get past it.

VERY little fuel pressure should be seen at the carburetor...about 5-6 psi.

If you have an in-tank pump, the strainer sock could be clogged up as well.  If its an external electric pump, the pickup tube in the tank also has a strainer sock, which could be clogged.

By 1985, pretty much all GMC based RVs with carbureted 454 engines had both a mechanical pump on the engine, and an electric pump near or in the fuel tank.  This was to prevent vapor lock.

Also, there will be a metal canister type fuel filter along the frame rail on the passenger's side...not always easy to find...and these can get clogged up as well, since they are hard to find and a lot of people don't even know they are there.

Kev

[HandyDan]

If it is a '85, then there is a good chance the chassis is actually an 84.  In which case it would not have an internal electric fuel pump in the tank.  They started installing them in '85.  There is a good possibility that the manual fuel pump has crapped out.  If you get an electric fuel pump and run some hose to bypass the manual pump, the motor will run on just the electric pump.  You might, also, have cracked, rotted rubber fuel lines in the system causing the line to suck air instead of fuel. 

[crenninger]

Thank you for all the suggestions.

1- The carb is a quadrajet
2- I checked the fuel filter on the carb, it's fine and was wet with fuel -
3- I do have a fuel filter close to the entrance step on the frame rail - this is where the auxiliary tank was piggy backed into the system - right now the aux is disconnected and the rear tank is directly connected to the front fuel pump.
4- we can not hear any sound from the rear tank - I think I will deal with this later once the engine is running with the mechanical pump connected to a gas can.
5- We did have the gas can higher, and nothing was flowing to the carb,

Plan for this Saturday
1- install a new mechanical fuel pump
2- make sure fuel is moving to the carb by disconnecting the gas line where the fuel filter is.
3- reconnect the fuel line on the carb
4- try to start the engine - which hopefully will fill up the bowl and bring gas.

I already know that the accelerator pump seems to work as I can see some fuel squirts in the smaller carb hole when pumping gas
If gas fills up the bowl, and accelerator pump squirts gas and the engine doesn't start/run, I am guessing the jets are clogged correct?
If that's the case, is my only solution is to open-up the carb and clean, or does the carb has some clean-out hole where I can spray carb cleaner and compressed air?

Pictures to come.

[crenninger]

Here is the new project...


mechanical fuel pump I am planning to replace Saturday

[DaveVA78Chieftain]

Chevy/GM P-30 Chassis Service Guide (A supplement to the regular Service Manual Set)

Top of page; Member Area; Manuals, Diagrams, & Tech Data;
Chevy/GM P-30 Service and Maintenace information
pdf page 135.
Not sure if your member status allows you access or not.

The Chassis Service Manual is a 3 volumn set.  Was a diffferent set for each year.

Vol 1 Chassis Service
Vol 2 Unit Repair
Vol 3 Wiring Diagrams

The Bishko CD contains all 3.

Dave

[bluebird]

When I bought my 80 Itasca it had been sitting for at least 6 years at the rv dealer ship. I had to drop the tank and replace the rubber lines, as they were rotten. I didn't have it running very long snd the fuel pump took a dump. If you are going to get this thing going and try  to make it dependable. Start by replacing the mechanical pump on the engine, and run it off a 5 gallon can. You need to take the tank down too, to make sure it doesn't have a lot of crap in it. I had to, to replace the lines anyways. Even if they don't leak now, they will, and you sure don't need to be 100 miles from home when they start leaking.

That'll clean up nice. Might be a little work but it'll be worth it.

[LJ-TJ]

Well from what I can see your not coming up short with ideas. Sounds like you got the process down pretty good. I think if you go with your game plan you'll know were you stand by the end of the day. The only reason I'm writing is to say Wow with a little wash job looks like you scored. Good luck on the weekend. Make sure you let us know how you make out.

[Lefty]

Not much I can add that hasn't been said here already, and yeah I'd go read that article I posted... it's written from the point of view that the rig hasn't been started in an unknown number of years and meant to get it to a point where it can be safely ran and driven for test driving purposes. Don't run an engine just on starting fluid though.. it dry washes the cylinders and can cause scoring. Use WD-40 or SeaFoam Fogging Oil instead.
Also, if it has been sitting for as long as you say, and there was fuel left in the carburetor bowls (engine fuel line wasn't disconnected and the engine wasn't allowed to run until it ran out of fuel), it is very likely that the needle has stuck in the seat in the shut position as the gas inside turned into varnish... this would prevent any fuel from entering the fuel bowls. You'd need to remove the top and see if the floats move freely to check this, it'd be wise to spray everything down with carb cleaner while your in there as well.
Mechanical pumps have a rubber diaphram that can become brittle with age, and it could be the problem, but if you put a temporary line to it's intake port and run it into a portable gas can, you can remove the outlet hose and turn the engine over to see if it's pumping or not. A good pump should fill a quart mason jar in around 30 seconds. Or, shoot a pulsating stream at least 2 feet.
The most common failure of rubber hoses are that they rot from the inside, out... This can cause a hose that looks ok on the outside to have a loose section internally that can cause a blockage, especially in one direction only... If you can blow thru a hose in one direction, test to see if you can blow thru it in the other.. sometimes the loose section acts as a one way flap, blocking flow in that direction.

Hope you get it going, if it will start on starter fluid and run... it can only be a limited number of things preventing it from running on it's own... at least you know the engine WILL run, and the other systems are all ok.

[crenninger]

Thank you all
I registered as full member and have access to the document now.
I did read lefty article, thank you for posting

I'll report my findings after the weekend.

[crenninger]

Or, shoot a pulsating stream at least 2 feet.

Definitely doesn't do that... Barely dribble out...

Regarding the carb, if I need to get to the needle/jets do I have to take the carb out of the engine or can I remove the top with the carb on the engine.

fYI I am used to rebuilding motorcycle carb for the last 20 years... First RV one so :-))

[cosmic]

go on youtube.com under search put quadrajet there is a very good video that should walk ya through the whole thing.

[Lefty]

Top comes off without removal, but I wouldn't ever recommend it. Too easy to drop a small clip,retainer or screw and never see it again.... or worse, drop it into the intake and hear it clink it's way all the way to the backside of the intake valve!!

I usually build mine on an old folding card table that I've had forever just for rebuilding and teardown of stuff with lots of small parts, I got it at a thrift store and re-did the top in white formica... makes it easy to clean, and easy to keep track of everything.
If you just remove the top, you likely can re-assemble it temporarily for test running the engine afterwards, but the top gasket probably will leak, and I'd really suggest replacing it or rebuilding the entire carb. Also, there is a small linkage on the passenger side that goes to the choke that will be a real pain to get back in place... plan for a couple hours of repeated trying to get it back on... theres no access to it except a small skinny screwdriver or wire, and sheer luck that it hits the hole eventually!! Been there, done that, and ask Kevin, he wen't thru it too...lol

I took my fuel line off today and turned mine over, it shot a stream of gas all the way to the radiator support, about 26"... it's an '88 P-30 with the same mechanical pump as yours, but mine was replaced last summer. So yours is definately weak if it only went a few inches.

[crenninger]

thank you for the carb / fuel pump shooting info
I'll update after Saturday's session :-)

[ClydesdaleKevin]

The Quadrajet is arguably the best carburetor ever made, IF its working right.  The downside its that its finicky and VERY complicated.  After struggling with Quads for years, we finally switched over to Edlebrock, with no regrets or loss of mileage.  With a gain in power too!

Kev

[doylexl]

I went throught this about three weeks ago when I bought my winnebago, it has the quadrajet also. I removed the top of the carburetor without removing the carb it self from the intake manifold. The throttle plates  stayed closed and I made sure that nothing had fallen down on the throttle plates before putting the carb top back in place. The hard part about putting the top back on a quadrajet is the metering rods that hang down from the underside of the carb top. The metering rods dont hang straight down they will lean to the rear so you have to be careful and get the metering rods in the correct holes as  you are lowering the top back in place. The linkage for the accelerator is hard to get disconnected and once the top is off the jets screw straight down in the front float bowls. Mine was clean and didn't need cleaning but the only way I could know for sure was to remove and inspect. I would recomend spraying wd40 in thru the carb while holding the throttle open to help raise the compression and also if you pour gas in thru the vent hole in the top of the carb and try to get it to start and run before removing the top of the carb. It worked on mine and it had been sitting for a few years .

[crenninger]

Thank you for the carb info.. One more day until I get the.... With all the help, I sure hope I will get it started.


Send good karma, Saturday around 9am :-))

[DonD]

Ahmmmmmmmmmmmmmmm..................................................

Ahmmmmmmmmmmmmmmm..................................................

[007]

yup ,forgot about that take a clean bottle like a shampoo or dish soap bottle that puts out a small stream and fill the float bowl through the vent tube , then it should run for a mimute or two till the carb runs dry , great idea doylexl. pulling the carb top off is easy , getting it back on can be a pain in the a** unless you get lucky and the metering rods hit there spot. if they go in the main jets the top sets down real nice.

[crenninger]

Karma was good today!! Thank you all for the advise... they were followed.

Replaced the mechanical pump, sprayed the carb, filled up the bowl from the vent with fuel, a few cranking and it ran!!! 

Off a gas can on the floor with the mechanical pump.

Next I replaced the inline fuel filter with a clear one and while the engine was running on the can ... no fuel in the filter from the rear tank :-(((

checked a few things and then dropped the tank .

Took out the tank fuel pump, and boy is it nasty, power is going to it (that's good), but it's not going - nothing.

Stopped by Napa & Kohlweiss (Local parts store) and they don't have the whole assembly.
Barely if they have the pump but they are not 100% sure it's the right one.

Looking at it, i'd rather replace the whole assembly.
Any hints/advice on where to get it?

see pictures below, I'd like the whole thing new.

[LJ-TJ]

Woah that is nasty. There was a chap on E-bay that had three new old stock for sale. If I can find it again I post it for you.