97 wont start

i have a 97 chevy 350 5.7L with CFI fuel system and has stalled when while driving. so we replaced the fuel pump and worked again. Just recently it stalled again and wont start so we replace the fuel pump, filter and regulator. And still wont start. We have spark but fuel wont get into the cylinders. We have exelent fuel pressure. We tested it. We replaced the distributor cap and the starter but still wont start what can i try because alot of people say to change it to a MPFI system but i allready have injectors to each cylinder and dont want to spend 750 dollers on the upgrade.:banghead:

Spark to all cylinders?
Is dist turning and timed right?
How much fuel pressure?
CSI or SFI fuel injection?
Check ECM-1 fuse in under hood fuse box.
Are the injectors getting 12 volts on on side and injector pulse on other?

I am having the same problem with my 97 chevy 350. Fuel pressure is at 50psi. Runs great once it is stareted. I had it hooked up to a computer, it showed all is well but it will not start cold unless I shoot it with starting fuid. What did you figure out on yours?

Kevinb

I am having the same problem with my 97 chevy 350. Fuel pressure is at 50psi. Runs great once it is stareted. I had it hooked up to a computer, it showed all is well but it will not start cold unless I shoot it with starting fuid. What did you figure out on yours?

Kevinb


This post is old and poster has not even answerback to start with.

If you want help with yours start a new thread and give all info.
Truck sise and engine and engine code and mileage and CSI or SFI fuel injection.

With 50 lbs fuel pressure it is to low on pressure.The only true test on a fuel pump is to check the direct fuel pressure from fuel pump.
A quick test is to block off the return line and see if fuel pressure comes up to 75-85 lbs.
But do not run the pump at full pressure very long.
Also when testing fuel pump and pressure you need to tape a gauge to outside windshield or outside mirror and drive it on the road for 20 -30 minutes
until the pump gets has run a while to check for a pump fading out after hot.

Hard to start cold or hot and fuel pressure testing guide lines.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
If pump has full pressure with return line blocked and low pressure without it blocked most usually the fuel pressure regulator is leaking or not holding pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak in system.
Post back fuel pressure readings.




Give us you full fuel pressure readings like.

50 psi is too low. It should be 60 or higher. I would look at the fuel pressure regulator that's located on the fuel injector "spider" under the plastic intake cover.

Also, stick with the Delphi fuel pumps. They will last unlike the cheaper parts store brands.