94 S-10 Vortec Starting problems

[jdpfister]

I have been having a time with my son's Vortec S-10 Blazer.

It started with picking up the truck and doing a complete tune-up and fuel system injection cleaning through the rail and through the intake. The truck runs great and has 50psi of fuel pressure on the rail.

The problem is it will not start. If it is warm I might be able to get it to start by quickly hitting the key and letting the motor turn. The truck will start right up with a little spray into the intake.

I have talked to many people and boy do they have a lot of ideas! I have tested the fuel pump "check valve" by pinching off the supply and return lines.

I am guessing that it is either the fuel pressure regulator although I don't know if it would run good with that bad. or the CPI Injector Assembly which I have found out now you can buy just the part (can't remember what it's called) without all of the injector lines.

Any ideas?

[Dans Collision]

Just in case you didn't solve your problem yet....

Had the same problem with my wife's S-10 with the 4.3 Vin W motor this past July.. Hard start but only when warm. Turned out to be the diaphram in the fuel pressure regulator.... it was leaking thus letting unmetered fuel into the combustion chamber causing the motor to burn rich. Now, I cheaped out and only changed the fuel pressure regulator, and it worked fine. I bought mine at www.1aauto.com Its a $50 part, but it beats $300 at the GM dealer for the whole injector assembly. The kit that I bought even came with the anti-tampering torx bit to do the job. If you want to be sure its the regulator, try the following....

remove the VORTEC cover - 2 bolts
remove the tuning valve - (under the plastic cover)
with the tuning valve removed you can see right into the plenum
shine a flashlight into the hole....if the left side looks clean and or wet that's your problem.

hope this helps

Dan

[swingerstraight]

try testing the fuel pump with a fuel pressure guage install it just turn the key (on ) watch pressure should be an initial drop about 10 psi then go down a little and stop no less then 30-35 psi