1990 Southwind Motorhome starting problem cont'd

You really need to find out if you have a fuel, electrical or vacuum problem.

One easy test is spraying WD 40 or starter fluid (short squirts) into the throttle body as soon as it starts to see if will continue to run.

Usually vacuum problems will cause a bad idle and not shut down, fuel or electrical can cause the shut down.

But is it fuel injection or Carb. My 1990 is a carb. I wonder if the ignition switch could be bad. I'd had a similar problem on mine where you could crank and crank but if you let off of the key it would start. but you could also wiggle the key and make it quit.
Click

Thanks alot, we'll work on that later today and let you know.

OK, wait one huge second. I think we have a different problem. If there is fuel on the butterflies, and some smoke, I would bet one or both of the injectors is sticking partially open. This is even more likely with the fact that this is an RV in that RVs often sit unused for extended periods of time. When you first turn the ignition on, the injectors pulse a little gas into the throttle body. There should be a mist that stops soon after turning on the key. If the injector drips after that, it is stuck. Try whacking the injector with the handle of your screw driver. You may even need to whack it, when the key is first turned on, to break it loose under power.

If you do not see a drip, and the fuel does mist when the key is first turned on, then I would go for electrical. Ignition coils can short out at the most opportune time. If the coil is partially shorted, you can probably get it to run temporarily by unbolting the coil from the engine and laying it on a piece of cardboard so it is electrically insulated from ground. I had this sort of thing bite me after an engine change in one of my Jeeps. I was sure I had not wired something correctly, but it turned out to be a partially shorted ignition coil. It would run for a short period and then die. I didn't find it, until I put an oscilloscope on the input of the coil. When coils short out, the normally short to the core, which is bolted to the engine. By unbolting it, you insulate the core, and it sort of works, or at least works well enough to conclude what is wrong.

I had the same symptoms on a 1990 chevrolet van, it was the fuel pump,
A short rubber tube in the pump was split, once replaced it ran like new.
you may see fuel..but check the fuel pressure..

when we first turn the ignition key, it just "clicks", on the second turn it will crank over and start briefly. With the air filter removed we saw fuel on the butterflies (it seems to be getting enough fuel)

We bought and drove it home (2 hr trip) last Sept without a problem. We gave it a test drive about 3 wks ago, and it was just fine. We actually sold it, but it broke down 30 mins after new owners drove it away. We refunded their money, towed it home, and here it sits.

You need to nail down what is really going on, electrical or fuel. The fact that it doesn't start on the first crank is suspicious. I lean towards fuel.

I would try giving it a shot of ether down the intake right at the first crank. If it fires, then you have a fuel problem. If you can keep it running with short bursts of ether, again confirms a fuel issue.

Good luck, let us know how it progresses.

Jeff

You likely need to change the fuel filter(s) You could also have a fuel pump problem ,and if the unit has a Carb ,that may require an overhaul.

How long has it been since this Old Gal had a Run? Old fuel can cause lots of problems with older rigs.