well, you guys were right... the filter didn't help ANYTHING... i have noticed that it ONLY does it when it's REALLY hot out though. oh well, to the shop she goes...

 

could be a clogged cat converter =/

 

My 2000 Jimmy does the same exact thing. I still haven't figured out what it is but I can say that It has been doing it since last summer and i have put about 15k miles on it since the problem started.

Mine also only acts up when it is 85deg and up outside. I put a fuel pressure gage on it at one point last year and found that when it stalls out (and wont restart) the fuel pressure is only about 40psi... Normal starting pressure is a little over 60-65 psi and normal running pressure is around 55-60psi.

It boggles my mine that 5 or 10 degrees of ambient temperature would have such a profound effect on the fuel pressure. It could be a bad fuel pump, bad fuel line, bad fuel pressure regulator, and the list goes on.... I can drive the thing for hundreds of miles continuously without any issue at all when it is less than 80deg out, when it gets in the 85deg + range i can make it about 10 - 20 miles and it usually starts acting up.

My mechanic can never duplicate the problem, since it only happens on really hot days after driving for 10-20 miles (he doesnt have time to cruise around for that long and risk getting stuck somewhere for even longer). My mechanic isnt the type to just throw parts at the problem without being able to diagnose it. So my solution has been to just not drive it when it is really hot out.


Please post back if your mechanic is able to solve the problem for you, i am curious to find out what he comes up with

 

Not sure how outdoor air temp would cause the cat to plug up every once in awhile

 

Yeah... Clogged cats typically stay clogged... They don't just swell up one day and return to normal the next.

Before going any further down the path of the fuel pump topic, you need to test the pressure. Rent or buy a fuel pressure gauge and see what the pressure is at the motor. Keep it with you and check the pressure when it shuts off on you. Your truck needs >55psi with the key-on, engine-off, pump running and the pressure should remain above 50psi for 10 minutes after the pump shuts off.

Now, other things that are temperature sensitive. The ICM (ignition control module) can have temperature/load dependent failures as can the coil. CLICK HERE for a good run down on how to test the ICM & coil.

This could also be the beginning of an ignition switch failure (see the link in my sig). This would be especially true if the engine shut down is accompanied by the 'security' light being illuminated on the dash.

 

thanks for the input guys. it's doing EXACTLY what toaks1's Jimmy is doing. 85+ degrees and after about 10 miles. i can drive it all over the place at any speed with no problem if it's 85- degrees out. no lights when it shuts down just the expected drop in RPM. and it ALEAYS starts right back up, while on the highway it starts it fires again on it's own...

 

Ok guys my 2001 blazer has done the same thing. I did some trouble shooting.

here is what i think is going on.

I noticed this only happing when it is hot. and my fuel take had in between 78-100 miles left according to the consol display.

My opion is that the fuel pump is not getting sugnificant cooling due to lack of gas surrounding the pump. Plus when its that hot vapors in the tank make it worse. Thus triping out a thermal switch somewhere in the line.

Fix on really hot days I make shure i have plenty of fuel in the fuel tank and the problem has not procisted.

Hope this can help

 

thank you, this makes perfect sense as i have note had more than 3/8 of a tank since all of this started...

 

The fuel pump does not have a thermal switch.
The fuel pump is cooled by fuel flowing through it. Not over it.
If the pump was in fact overheating, then I would think the truck wouldnt start up right away. It would take quite a while for the pump to cool.

I suspect there is something else going on. Probably electrical in nature.

I

 

this has worked for me so far. I don't know why. I understand that it is cooled from the fuel going through it. But when there is a bigger void in the tank above the pump because the tank isn't full and it is 85 + degrees. The Fuel pump is going to be hotter in the tank, causing the pump to over heat. Add your fuel sloshing around in the tank with driving. I'm no expert but it just makes sense to me. And has worked for me. If it doen't work for me Ill go back the to drawing board.(sorry I just proof read this thing and it sounds to me like im angry and taking stabs at kris but im not THAT JUST THE WAY I TALK LOL)