Hey all,

My Jimmy will cold start just fine, but after driving around for a while, then turn the engine off, it doesn't want to start. It cranks, just doesn't start.

Now, one thing that I have noticed now is that when I try to hot start the truck, there is no sound coming from the fuel pump. Do you think it could be a bad/corroded connection, or do you think the pump is going bad? I can't see why the pump would be bad if it works perfectly fine from a cold start, but hey, I don't know, and that is why I'm here asking!

 

I suggest having the ignition control module (ICM) tested. Hot start failurecan bea symptom of the part going bad. I believe AutoZone can test it for you, but be sure they do it ~6-10 times in a row to be sure the part gets hot.

 

Now, where abouts is the ICM located? I don't have my manual at the moment. Oh, and I have a 2001 GMC Jimmy.

 

Alittle vehicle info??

For all 2nd gens, the ICM is located to the left and slightly behind the throttle body (looking from the front of the vehicle), just off the inside edge of the passenger side valve cover. It is will be mounted to a bracket and heat sink.

As Rich said, when you have it tested, have it tested repeatedly. Most ICM failures occur due to heat, but once they cool, they work properly.

 

Well, like i said, there is no sound coming from the fuel pump, so is that related to the ICM?

I am going today to get the ICM tested, so well see what happens with that.

I have a 2001 GMC Jimmy, 4.3L, 120,000 miles.

 

No, the fuel pump and ICM are not related. If the ICM checks out OK, we'll go from there.

 

Well, I went to get the ICM tested, and on the first 3 times it tested bad. Hopefully this is the cause of my problems.

 

Alright, I installed the ICM, but I am still having problems starting. I now believe that it is the fuel pump. I sprayed some starter fluid into the intake, and when I attempted to start it, it turned over for a few seconds, then went back to cranking.

Now, what i want to check is the connection to the pump, but would i be able to check it without dropping the tank?

 

Next we check the fuel pressure as I explain in this thread.

 

I'll have to get a hold of a fuel presure gauge somewhere, but there wouldn't be any pressure if the fuel pump doesn't prime for 3-4 seconds when I turn the key to the ON position, correct?