montana warm start problem

[buckeyball]

I have a 2004 Montana. Our problem started last summer. It turns out that on hot days the van won't start when it's already warmed up. It never has a problem starting the first time but if you run two or three errands it eventually won't start again. It does turn over and usually starts briefly. However, it will immediately start to sputter and then the engine dies. After that it will turn over but doesn't catch. If you let it cool down for 30 minutes or so it will then start up again.

Again, this only happens on warm summer days and wasn't a problem all winter. Now this summer it's happening again.

Anybody have an idea of what might cause this?

[dewaynep]

Have you tried holding the accelerator pedal to the floor when this happens? That wiould put the pcm in "clear flood" mode and turn the injectors off, not adding any more fuel. The reason I say this is you may have either a sticky injector that dumps raw fuel into the intake or a bad temp. sensor that thinks the engine is cold and delivers more fuel for what it thinks is a cold start. If holding your foot to the floor works you will need to get some fuel pressure bleed down readings and/or see what the temp. sensor is telling the pcm the temperature is. Hope that helps.

[rkvons]

Have you ever changed your Crank Position Sensor? I have a similar problem with my 1998. When it's warm, it seems to have trouble deciding how much gas to give it to have it idle smoothly. It sorta reves up and then almost stalls out. I usually smoothes out and runs okay within 5 seconds of starting, but occasionally dies. It then requires some cranking to get it started. I would suspect that if the CPS got hot and did not work right anymore, It would appear to the PCM that the engine was not turing over. Just something to think about.