Hey Guys,

Man was I happy to see there's a forum for Blazers !!! I really hope you guys can help me out with this issue, I love my Blazer but I can't keep using it until I fix this issue, it has a few mechanics up here stomped.

Basicaly the truck runs great in winter, never had any issues !! But on warm summer days it will do 1 of two things.

1) Will stall at a stop sign or red light, actualy stalle don my once on the Highway while driving the limit, and then won't start, engine just turns endlessly.

2) Runs great, I stop to pick up a pack of smokes, jump back in the truck... won't start, engine turns endlessly.

In both casses if I wait anywhere between 20 mins to 3 hours, it will start up again.

This only happens when it is really warm out, but keep in mind my Temp gauge is never high, never any signs of overheating. Change the ignition Coil thinking that would help but it's a no go. Thinking maybe ECM ?

It's weird all the signs of oveheating yet no smoke and temp gauge is normal.

Note : Not sure if this is relevant or normal on these models, but when I accelerate my Oil Pressure gauge goes up, when I let go of the gas it goes back down ( Not all the way back )

Anyways, any suggestions would be great, also if anyone could suggest a good place to get a legit ECM hehe

Cheers !!

Jo

 

Check two things the next time this occurs, fuel pressure and spark.

Oil pressure increases with engine RPM to a point. It is normal for it to increase when the RPMs are increased.

 

Thanks for the reply :-)

When I brought it in last time this happened the mechanic said everything was in order, sparks are fine and fuel is flowing. Keep in mind he tested these things while the truck was not acting up.

Could something be causing either sparks or fuel flow to stop when it is hot out and then once it cools everything goes back tonormal ?

Note : The fuel pump was changed 2 years ago


Thanks again guys for your input !

Cheers,
Jo

 

You have to test it when it is acting up. Both the pump & the coil/ICM can experience heat related failures and could act perfectly fine after cooling down. The fuel pump usually will only do this when the tank is near empty if it is a heat related issue as the pump is cooled by the fuel (the more fuel in the tank, the cooler running the pump is).

 

Excellent ! Thanks I will try it out. Going to google how to check fuel pressure lol

I will let you guys know the results.

If anyone else has any other ideas please let me know.

Thanks,
Jo

 

Check out the links in my signature.

 

Thanks, some good info in there ! Going to buy a electronic Fuel gauge from ebay so that I can monitor it as I drive and as it stalls. Don't want to have to install a fuel line tester on the side of the highway dressed up in my suit lol

Cheers,
Jo

 

Mine does exactly this as well, I have determined it to be fuel pump. I couldnt figure it out either, then I started keeping my fuel pressure gauge with me, and each time I would check the pressure and it would be low. It needs 50-60 psi to run, if the pressure is low it wont start. I just make sure the tank doesnt go below 1/2 tank when its hot and it doesnt happen.

 

Alright, I have finaly got a pressure tester, and here are my results on a nice warm sunny day at a gas station when my truck wouldn't start :

- Took about 10 minutes to setup pressure gauge and smoke my cigarette :-p
- Turn key, fuel pump runs, check pressure = 0 psi
- Wait 5-10 mins
- Turn key, fuel pump runs, check pressure = 20 psi
- Wait 5 mins
- Turn key, fuel pump runs, check pressure = 35 psi
- WAit 5-10 mins
- Turn key, fuel pump runs, check pressure = 52 psi
- Removed tester, turned key truck started no problem.

So it is clearly pump related I believe, my question is... why only when I turn it off, I drove a 3 hours drive on highway and mountain roads towing my boat with plenty of idle times in hot weather and it never stalled once, turn it off and then it won't start.

So assuming you guys agree with me and it is the fuel pump itself and not a relay or something like that, what pump do you recommend, that you know will work hehe.

Cheers guys ! Aprpeaciate all the help !!

Jo

 

ive got almost exactly the same problem.ill drive it 2 days no problems,then slow down for a light and it stalls.wont start back up.as soon as the tow truck driver pulls off,i go to start it and it starts no prob.changed fuel pump and filter thursday-ran fine friday and saturday but died again sat night-got it towed-started back up-3 tows in the past couple weeks-scared to drive it to work-i keep hearing about a wiring issue involving the rear lights and brakes -and hooking a ground from the neg to the frame-i drove it through a puddle a few weeks ago wondering if i may have got something wet-very stumped