I am completely new to all this forum stuff, but I have a friend that uses forums to get information, so I thought I'd give it a shot.

I have a 1997 Blazer with the 4.3L Vortec CMFI Fuel System. This stupid thing WILL NOT start!! Before it would only do it when cold. Then lately more and more. So I tested the pressure and noticed it was dropping on the return side. I replaced the pressure regulator and now the car won't start at all. The plugs have a GREAT spark but are dry. The fuel pump is priming, pressure is there along with fuel. So far my belief would have to be somewhere between the supply line and the spark plugs ............ fuel injectors? Pump with not enough pressure??

Can anyone help me?

 

What are the pressure readings
1. With the engine off, but the key turned on.
2. With the engine off and the key turned off.

 

Yeah, we need to know what pressure you are getting at the fuel rail on the engine to properly direct you. Have you double checked your work? It is quite easy to bend over a pin or two on the main spider electrical connector on the top of the plenum. But that would only explain why one or two cylinders would be without fuel.

 

I'm not exactly sure what the psi is off, but I do know with key on, it's 44 psi.

I dumped about 2" of fuel into the throttle body. Cranked and started!!!!! After about reaching closed loop, turned the car off and it held the pressure and restarted the car again and it worked. Test drove fine.

After a few hours, again, nothing.

I believe it's the fuel pump now. And am I wrong? Is that one whole unit - pump and sending unit sold together? And does anyone know the approx cost of this unit? I think I found one for about $130.

 

My daughters Blazer had this exact problem, and it was the fuel pump. She had a friend replace the FP and it fixed that problem but he did something wrong and now she has another issue. I placed a POst in the Engines and transmissions forum asking for help with that. Good Luck

 

Sad thing is ... these pumps/sending unit for a 4DR 4.3 are NOT cheap!!!

 

Yea, I know, You could try Autozone, I find them cheaper than most part suppliers, and if it's a car you dont figure on having for many more years you can go to a salvage yard.