I have a 99 st10 blazer that dies at idle with in 10 minutes.
It does it hot cold when ever. I've replaced the EGR and i'm currently hunting for vac leaks.
I've pulled the O2 sensors off same result. if you pull the intake plastic tubing off it gets worse.

Help

 

Just a guess...Idle Air Control vavle?

 

After trying different things one night...the next moring the truck wouldn't start at all. I replaced the fuel filter and the truck started up. But the stalling problem has not gone away. I'm thinking its a fuel pump going bad or a regulator leak in the upper plenum.

Any thoughts.

 

The first thing I would do is hook up a fuel pressure gauge. This will let you know if you have a fuel supply problem (by watching the pressure when the pump is running) or a leak down problem (by watching the gauge when you turn the key off).

Other than that, you could clean the throttle body (I like to just remove it to clean it thoroughly), the MAF sensor (be careful!), the EGR valve (new gasket required - screened gaskets are available), and checking and/or replacing the plugs, wires, cap & rotor.

 

I got out of work todaygot in the blazer started up i back out of the space and 10ft later the motor died and could not get it started again. I had it towed to my house. I then tested the fuel pressure with a gage I just bought. pressure came up fine. I pulled of the gage and about a 1/4 glob of snots came out with the connection of the gage. I then tried to start the car and it did. this is not cool!!!!! I can't tell if the truck is reliable enough to take back to work..... Is the regulator screen clogged up? crank sensor or ignition problem??
I wish I still had the problem I wanted to see if it had spark. Jesus???

 

"glob of snot" doesn't sound good... Sounds almost like the fuel was gelling which doesn't happen with gasoline... Have you tried any fuel system treatment or fuel antifreeze (ISO heat in the red bottle)?

 

I've never used any treatment in my fuel. Are you saying to try and use some?
I have a new fuel regulator that i'd like to put in. the new one i havehas a very fine mesh screenattached to it.I'm thinking that might be filled with thesamejunk. I'm just afraid of what i'm going to find under the plenum. Such as a huge mess. I would assume the injectors would be ok since its running again. Its not dying either at Idle. But I don't want to drive it long distance yet. last tow was $66.

What does the CID motor stand forand how are the injectors fired in this system electronic sequencial. Not like the old 94 motors. I'm also wondering if the vacuum line inside connected to the regulator is ok.
Its been 160,000 miles new motor and new trans. I did myself. not the first blazer i've had last one was an 88 I dumped it at 250,000.

 

Not sure what you mean by CID... The '96+ motors are SCFI (sequential central fuel injection). This system has six sequentially fired injectors located in a central injector pack. Each injector feeds a pressure actuated poppet nozzle that requires 50psi to open. The poppet nozzles are often the problem with this setup, but if it is running properly, you should be ok.

About the FPR, if it is running, it is not the problem. I would recommend you atleast run some ISO Heat through a few tanks of fuel and possibly change out your fuel filter after words. Then run some Chevron Techron Concentrate Plus through a few tanks as well.

Gasoline should not gel, what you described as snot. In fact, it is quite difficult to get gasoline to gel which is what has me confused as to how it managed to happen in your fuel system. But, once you cleared the clog and have things running smoothly again, you should clear the system out with a water remover (ISO Heat) followed by a fuel system treatment (Chevron Techron Concentrate Plus).

 

Took the blazer to work today ran great going to work. Drove another 25 miles and motor died. Then kept on dying when ever i went to stop. I took the plenum off the everything is fine underthere replaced the regulator and gaskets. I think its a sensor somewhere thats giving up. My friend thinks its a crank sensor going which would make sence no code dying at idle. Idle air would not be it because it would start if I press the gas peddle.

 

LOOKS LIKE I FOUND THE PROBLEM!!!!!!!!
I got the truck to die again. I put the inductive timing light on and watched the motor die. It was hard to tell if I was loosing spark because it died so fast. Then the motor wound not start for a few cranks and definatly no spark. I was poking around when it would start. I pressed on top of the coil power plug and bam it died instantly every time. pulled the one of the power wires in and out of the plug no problem. I took the wire of of the connector removed the bad spot of wire reconnected it and ran no problem everytime.

It just goes to show you need 3 things for an engine to run spark fuel and compression. Look at those first before all the high tech sensors that are bullsh!t.

Thanks for all the help.