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John H. · 12-20-2009, 02:23 AM

I have a 454 4 brl. engine in a 345 , 89 A.S. and ever since this past Sept. a new issue has developed.

I went through a time in August when the auto choke did not work at all.

after it quite ! I sprayed a can of Carburetor cleaner through the system ! Coincidence?

Now the auto choke works great ! But after 30 seconds from setting the choke, starting the engine, starts right up every time ! it just dies?
I let it set for 30 seconds or so, starts right up again !
warms up, idles fine and runs fine

Now if I stop at a rest stop, for ice cream or whatever? for 20-30- minutes or so. Start it up and go, after a 100 yrds or so the engine dies instantly?
sounds like NO GAS or NO AIR????

Let it set for 60 seconds or so ??? starts right up and runs the rest of the day ???

Is this electrical or fuel, does not need to re prime so can not be OUT of available fuel !

could this be something to do with the auto choke, or a censor ???

Thank you for your help
John

Phoenix · 12-20-2009, 04:55 AM

Do you smell LOTS of gas when it dies. I had a similar problem, where it would start and run OK, then the carburetor float would drop down as the fuel was used and get stuck and flood out the engine.

You might want to take off the top of the carburetor and check out the floats. They might be sticking, or if you have one of the old metal floats, it could have worn down and sprung a leak, in which case it would be full of fuel (and won't float).

Also, you might have a bad valve seat or dirt/contamination in the carburetor bowl that prevents a good seal.

If you are not very mechanically inclined, I'd check on having the carburetor rebuilt. However, you'll likely have less problems having the old one rebuilt, than with purchasing a new or rebuilt carburetor (to replace the old one), as there are frequently compatibility problems between what look like the same models of a carburetor. This engine has been in production for so many years that the carburetors changed a lot over time, and even though similar models may look the same (or similar) externally, the interiors are different. Therefore, it is always simpler to rebuild the same carburetor, because you know it will work (after repairs).

Good luck...

Jammer · 12-20-2009, 05:42 AM

Sounds like vapor lock. Is it worse in hot weather?

ROBERT CROSS · 12-20-2009, 06:58 AM

The 89 454 should have throttle body injection, unless the MH's are different.

Can you have it checked for fault codes. I assume the service engine light is not coming on. One of the common problems for starting/stalling problems without a code is the crankshaft position sensor, my old school method for checking, douse it with with water while running, stalls you found it. May also be an intermittant open circuit in the distributor ignition module.

I would also check the fuel filter for blockage and the pump for pressure.
The egr and map sensor could give similar symptoms but would usually throw a code.

John H. · 12-20-2009, 07:21 AM

Thank You all, No, we do Not smell gas !
" No engine code " !
Vapor lock? No, it is getting more frequent with this cold weather !
I Visited with a friend Saturday that has a 1989 Chevy truck with fuel injection.
the M.H. has a 4 Brl. Carb. ???
12 volt intermittent ? distributor ignition mode? Now that is what my Boat mechanic says that tunes racing boats

I will have to Hook it up to a tester, and see if they can throw a Fault code Bob, I assume ?
Any other thoughts are sure welcome, as it will be after the 1st. that I can get it into a shop.

bill & phyl · 12-20-2009, 09:13 AM

howdy

Could be an EGR valve staying open at idle cold use hand held vacuum pump to check operation. Check for vacuum leak on manifold and related vacuum lines using propane torch engine running move propane torch over intake manifold and vacuum lines if engine speeds up you found your leak. the ignition module is a very real possibility chevy are famous for this problem not expensive to replace have always used a scope to fine the problem

Merry Christmas
Bill

John H. · 12-21-2009, 04:46 AM

Just before this ( shut down ) symptom started! we had some time in a campground and I removed the Banks air cleaner cover, cleaned the filter, oiled it and while drying I painted the cover and sprayed the Carb with a can of C.C. as per instructions.

I had run into Auto Zone, purchased a can of Red engine paint for the Air F.C., an air filter cleaning kit, and the can of carb. cleaner! I also re arranged some loose wires, found a connector loose at the distributor cap, re connected and now the engine tach. works again ! I my have pulled loose, or broken the seal on a vacuum line someplace ??? Because when running down the road it could not run better, and after warm up! Idles great.

garry · 12-21-2009, 07:33 AM

When it shuts down does it just quit running or does it stumble and quit.

Normally sudden stop I would think 12V, stumble I would say gas.

However; it was running OK you clean the carb then you have problems!

Time to take a closer look at the carb.

John H. · 12-21-2009, 08:05 AM

Hello Garry, It does NOT stumble, I shuts down, no cough or sputter !

If I am leaving a rest area, I try to PUMP the throttle ? Nothing, just shuts down
Like it will not accelerate past a certain RPM. then turns OFF, shuts down.
Let it set 60 seconds, starts right up and runs all day long perfect.

John

68 TWind · 12-21-2009, 08:20 AM

I would look for a vacuum leak. When cold extra air will make the mixture too lean and the engine will die. When you put a load on it, drive it, it goes dead, that says fuel. Electircal stuff tend get worse when hot, not alwayss. But, you should be able to keep it running by pumping the gas pedal if it is going lean from extra air. That will cause a squirt of raw gas into the carb throat which will instantly make the mixture richer. If pumping the gas padal won't keep it running then look for fuel delivery or other problem . Fuel pressure will need to be checked. The fact that it runs fine after it gets warms just makes me think it is going lean from a vacuum leak. A hot engine won't need as rich a mixture and will run OK. Newer engines with EFI can compensate somewhat, the computer will send more fuel. Older carb engines can't compensate,

GlenCoombe · 12-23-2009, 01:19 PM

Don't the 345's have an electric fuel pump? My 28' FC actually starts, stumbles and stops due to fuel starvation. On the second start all is well as the mechanical pump has by then had enough strokes to bring the fuel back up to the carb... or so I think.

Is your engine in fact TBI?

klattu · 12-23-2009, 02:41 PM

Most likely you have a 1989 Airstream on a 1988 P-30 chassis.
Remember this when ordering parts...its a '88.
Sounds as no gas...if it starts right up after sitting.
If it was flooding from too much fuel, would not start quickly.
As it sits without running, fuel trickles thru filter, and builds up enough to run...thats my thoughts.
Mine does this randomly, until I change out the filters...
1 at tank
1 on frame
1 at carb

But it runs all day after a few stalls...not sure about this. problem

ROBERT CROSS · 12-23-2009, 05:02 PM

John,

Simple first, have you replaced the fuel filter and checked the pressure.

If the filter is restricted, you can sometimes get an acceptable pressure with a very low volume.

Does it feel like you just turned the ignition off, or is it low power then stall?

John H. · 12-23-2009, 05:42 PM

Klattu, Robert, I do think that the fuel is the issue. No, No flooding, when I leave the rest area, By the time I am ready to enter the HWY it is like the Key is turned of !!! maybe when I go to axcellerate ??? come to think of It. and My fuel Pump, sitting in front of the tank, Makes noise ALL the time ? In the coach it sound's to be comming from under the fridge or under the toilet ??? should it be that LOUD ???
and Pumping does Not Help? But I think with the low speed as I exit a parking lot or rest area, I am not giving any throttle ! Then when I do ? No response, and it dies 1

I have ALL new filters in Hand, But have not installed because I have been so busy with so many other projects. Loose flywheel cover, loose starter heat shield cover, oil and filter change and on and on.

It runs so good down the road that I have let the installation of the filters go ???
But I will install them when I return to the storage garage after we return from N.J. in Mid January
Yes, I get parts for an 88 model as mine was deliverd to airstream in October of 1988.

ROBERT CROSS · 12-23-2009, 07:09 PM

John

If the pump sounds like an ambulance is chasing you you probably have a restricted filter . The pump can be a little noisy and work fine, but it's very likely that a restricted filter is causing the excess noise. Try that first.

When you say it's, "like the key is turned off" has the engine stalled or is it running with no power? That could indicate another problem.

garry · 12-23-2009, 10:10 PM

It sounds like when you shut off for a few minutes and then start it back up you are burning the fuel in the carb bowl then run out of fuel.

Why would you run out of fuel?

A restricted filter but this usually shows up as "idles great" but backfires or runs bad pulling a hill or under a greater than normal load.

My theory;

A small hole in the diaphragm of the mechanical fuel pump allowing gas to drain back into the tank when you shut down.
When you start back up you burn the fuel in the carb then run out of gas, you also get a shot of air to the carb before the pump pressurizes, crank it back up and all is OK.

This would not happen on the 1st crank-up of the day since you crank it longer before starting and the choke helps pull extra fuel.

I wonder if it would happen if you just let it idle for a short time before taking off?

John H. · 12-24-2009, 08:33 AM

Quote:

Originally Posted by ROBERT CROSS

John

If the pump sounds like an ambulance is chasing you you probably have a restricted filter . The pump can be a little noisy and work fine, but it's very likely that a restricted filter is causing the excess noise. Try that first.

When you say it's, "like the key is turned off" has the engine stalled or is it running with no power? That could indicate another problem.

Robert,
The engine if NOT Running

The 1st. time this happened, It was hot, we had gone to Millersburg tire and had all new skins put on.
We stopped outside of Loudonville for ice cream.

I started the engine, pulled to the stop sign. then onto the road, went about 100 yards. and started to accelerate ? fluttered like ? Pumped the peddle but she was Flat Dead !!! We sat 60 seconds on the road, It then started and ran all the way back to Marion Ohio but has been doing the same thing ever sinse ??? I thought Vapor Lock ? But now that it is cold ? same thing.

When you say it's, "like the key is turned off" has the engine stalled or is it running with no power? That could indicate another problem. __________________

LOST IN THE SIXTIES

I am going to install the fuel filters that I have in Hand and will now pull off the fuel Pump that sites in front of the tank !

Thank You all, Hope we are getting close ???

gunner · 12-24-2009, 09:06 AM

The electric fuel pump may run fine but not pump fuel. That was the case with mine. I checked it by pulling off the outlet hose and turning it on with a battery charger, the motor would run but no fuel came out. I then replaced the fuel pump and did the same test and it pumped a stream of fuel. The reason I checked mine, when under load it ran out of gas, had to back off the trottle to keep it running, it was primarily doing it going up small hills.

John H. · 12-24-2009, 09:51 AM

Thank You gunner

Merry Christmas everyone !!!!

Auretrvr · 01-02-2010, 08:32 AM

Guys, I went through a similar process with this--engine stopped dead shortly after starting. I replaced the fuel pump but that did not fix it. The problem was a failing ignition module in the distributor.

Check for spark immediately after it dies. The ignition module, when it is failing, sometimes does so when it reaches a certain temperature.

I posted this issue last summer.