Winnebago Won't Start in Morning & Damp Outside

[Leahbyers78]

1994 Winnebago Adventurer 34 foot
GM 454 Motor

Replaced the following: full distributor (cap, rotor, plugs, wires) Oil pressure sensor; Will not start when damp outside. New battery.

Injectors spray in the fan like they are suppose to and no dripping when you shut it off.

Tried to start this morning at 7:00 am and nothing - won't fire. Started at 10:00 am and idled a little rough but running. This has happened a few times.

Suggestions?

[Leahbyers78]

We took it into the shop and they checked fuel pressure and it was just fine. They changed out something in the starter and now it works just fine.

After much thought and much money being dumped into the 1994 Winnebago...we upgraded to a Fleetwood Pace Arrow. This one come with a warranty so it makes me relieved to know I won't be dumping so much money into it.

Thank you everyone for your responses. It helped as we looked at the problem in a different way and learned more about our RV.

🙂

[frankdamp]

No, I really wasn't standing outside!

[siggyd777]

Try to start it on a damp night in the dark with the hood open,you may see the flashes of light or the sparks.
Siggy

[khogle2]

You need a spark tester to establish if you have spark at all. Don't just pull a plug and look for spark by grounding on the head or something.
And a coil test somewhere.

From memory: no guarantee

Ignition module is suspect. If installing a new one, they have heat grease included (or ask the parts man) to spread on or you'll be putting another on soon.

(Not the pickup coil by the way. If that was bad, you would not be getting either fuel or spark)

So from the pickup coil, the ignition module provides the reference high signal for fuel, but in this case more significantly, is also the on and off signal to collapse the coil based on the pickup coil signal. Sometimes only one side works, explaining the injector pulse, but no spark.

PS: I think these had a powder metal reluctor in the distributor which used to crack and shift on the shaft, but that's probably not the issue here
I think and hope.

[hershey]

Pull the distributor cap off on the damp morning as if its getting condensation in it, you will see it in the cap.

[Daveinet]

wildmanbaker wrote:
Dave, that's a good point, but isn't the coil in the cap on that year?

I don't think so. My multiport Edelbrock is based on a '93-'95 GM ECM (bank fired). The coil is separate from the dizzy on mine. The dizzy contains a servo for timing advance. The servo is controlled by the ECM, so assuming his ECM is of the same vintage, the dizzy would have to be the same.

BTY: If it does run with the coil isolated, I would not shut it right back off. There should be a separate physical ground wire that goes to the engine, but it could still want to send a small amount of noise back to the ECM. Long term that could be hard on the ECM.

[allbrandauto]

as a owner of a automobile shop saw this all the time change coil

[Emptypockets]

Sorry I can't help you with your situation - however, it reminded me of days long ago when we had cars with the problem you describe. Isn't it interesting how ones mind works?

[wildmanbaker]

Dave, that's a good point, but isn't the coil in the cap on that year?

[Daveinet]

My instincts wonder if maybe you have a coil that is going bad. I know people have mentioned issues with after market wires, but I have yet to ever have a problem and have always bought after market. Next time you have an issue, unbolt the coil from the engine and lay it on a piece of cardboard and try and start it. When coils go bad, most of the time they short to the core. If the core is isolated, it will prevent it from shorting and it will run.

[rgatijnet1]

This product, or similar products, are available at most auto parts stores. Try it on one thing at a time and you will find your problem. First pull off the distributor cap and spray everything inside to see if that works, and then go from there throughout the entire ignition system. Ignition spray

[More_To_See]

You might be able to narrow down your problem with a hair dryer.

I had a 1974 Datsun 260Z that would not start on cool mornings and it turned out to be the electronics box up under the dashboard above the passengers feet. I'd just run a propane torch over it for a brief second or two and the car would start immediately. And I sure don't remember how I figured that out.

And for another problem I had as a kid. An old dodge would occasionally just quit running. Stop dead. The problem turned out to be in the distributor. It had dual points and the insulation wore through on a wire pulled tight across the moving arm on a set of points. Every few days it would just short out briefly for some reason. I think I found that problem by shotgunning it.

[azrving]

midnightsadie wrote:
just a tempory fix put a 75watt light blub under the hood for the night.

Doing this will further help prove that you have wire, cap, rotor problem as it will dry things up. When it is running you could also mist it with a water bottle, if it gets worse, you have proven even more where your problem is.

Just be careful to not blast it and get zapped. Sort of like peeing on an electric fence.

[azrving]

I had a Silverado 4.3 would not run on after market wires. I also worked on a buddies S10/4.3 that ran rough all the time. He replaced everything, even the intake manifold gasket. I looked it over and suggested buying GM. He said he didn't care how much it cost, he was so sick of messing with it. He replaced the cap rotor and wires and it ran perfect. I know people will say that with newer vehicles troubleshoot and replace only the one bad wire with oem.
The wires I bought and the ones he bought were not cheap, they were the good ones.
Don't do this on what I'm saying, have it checked out, I dont want you to waste your money with my internet evaluation but it is something to consider.
Also try searching for that problem and aftermarket wires, I think I found others saying the same thing.

http://www.gm-trucks.com/forums/topic/66081-random-misfire-on-5-8-running-rough/

http://www.tahoeyukonforum.com/forum/showthread.php?t=30308