Hello all im new here and I have a bit of a issue. I have a 1993 Chevy S10 Blazer 4x4 with a 4.3l CPI with 222k miles. Every now and then it will start and idle just fine, sometimes it wont start at all. When it does start and when is around 2500 rpm it will sputter until it reaches about 3000 rpm and runs fine. Sometimes when I press on the gas, it just immediately dies and won't start back up. I have replaced parts left and right trying to figure this out and I am stumped on it as this has been happening for a few months now.

Here is what has been replaced:
Fuel pump, fuel filter, spiders, fuel nuts, spark plugs, spark plug wires, distributor, cap & rotor, ignition coil, harmonic balancer, timing chain.

The fuel pressure with the key on raises up to 62psi and when running it is at 58psi. The EGR has been cleaned and I can't find any noticable vacuum leaks. The harmonic balancer was replaced when this first started happening as I couldn't get the blazer in time and found out it had slipped and since I had it torn down that far I figured I would change the timing chain also.

To me, it seems like I replaced almost everything on the ignition and fuel side. Does anyone have any ideas on what I should try next?

 

Might be worthwhile checking fuel pressure and leakdown at the service port AND at the fuel filter outlet. This thread will help. Post all 4 readings and we can help you analyze them. https://blazerforum.com/forum/2nd-ge...eakdown-88305/


The electrical connector at the fuel injector has been known to develop a poor connection which can cause issues similar to what you're describing. The pigtail is available at most auto parts stores.

 

The fuel pressure at the service port will go up to 62psi and drop to 56psi in 10 minutes.

I am going to run by Home Depot today and get the adapter for the fuel filter and I will post back with the readings.

EDIT: Got the adapter and at the fuel filter it goes to 84psi and drops to 76psi in 10 minutes