97 Tahoe runs a couple of seconds and then dies

[souperbee]

We are working on a 97 Tahoe 4wh dr. 5.7 vortec. This is what we have. BTW it has 230,000 miles on it. Check fuel psi. 58 to 62psi. Replaced fuel filter, (had small amount of water in it) Dropped tank and cleaned installed new fuel pump. First pump wouldn't even run. Return, 2nd pump runs 60 psi engine starts after 2 second prime then dies as if starving for fuel. spray fuel in throttle body and engine keeps running. Get another fuel pump and is doing the same thing. I don't think it can be 3 bad pumps although I've seen it happen. After 2 second prime engine starts and runs a few seconds, sounds real good then acts as if it is starving for fuel. take spray bottle of gas and it keeps running. The vehicle has new spark plugs, distributor, new fuel relay, fuel filter, blew out the fuel lines. 3 fuel pumps. Took intake and cleaned all the fuel lines and injectors, The only thing we didn't do is check the fuel regulator. How do you check the fuel regulator? Would this cause the problem? I am open for suggestions it is driving my neighbor crazy. What are we over looking. Btw did a vacuum test and it was good. No vacuum leaks. needle nice and steady. Suggestions?

 

[lesterl]

With Pressure guage hooked up, observe the PSI for the fuel pressure when cranking and after it starts/ then dies.

Unplug the MAF sensor (the electrical pigtail), and retest. Ohm out the CTS sensor also.

 

[souperbee]

lesterl........I want to thank you very much. The connection to the MAF sensor was bad .I can't believe something that simple gave us so much grief. Anyway Thank you very much once again.
-souperbee :happy160:

 

[lesterl]

It does tell the PCM how much air is comming in, it then calculates a fuel charge to go with the incoming air and injects it, if the MAF malfunctions or the like, then it thinks low/no air, and a corresponding ammount of air. The PCM ignores this input upon startup untill the signal stabilizes.... yours didnt, so it stopped the fuel flow. MAF can get dirty and cause fueling issues also.

Glad you gott'er going.....

BTW the ignition is almost standalone........