S10 Intermittently Will Not Start

[wreck1998]

I have a 1998 S10 4.3L that two weeks ago would not start after sitting for about a week (it would crank but it appeared it was not getting fuel). I went back the next morning and it still did not start so I had a towed to a shop which checked the fuel pressure and it was fine. They diagnosed it as a fuel injector problem and replaced the fuel injector assembly.

This morning the same thing happened but this time when I gave it one more try about an hour later the truck started. Rather than just start replacing, I am looking to see if anyone has any ideas for troubleshooting.

Thanks.

[MT-2500]

A quick test on fuel delivery problem is to give it a shot of carb cleaner in air intake.
If it fires up with/on carb cleaner you have fuel deliver or fuel pressure problem.

Run a complete fuel pressure test.
What was there fuel pressure reading on it?


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.

[nuckolls_7]

i am having the same problem with my 98 blazer right now. Did you find out how to fix it?

[MT-2500]

Originally Posted by nuckolls_7

i am having the same problem with my 98 blazer right now. Did you find out how to fix it?

I hope you have better luck on a answer than I did.:sarcasm1:
Many people post and then do not follow up.

But if you need help on yours start a New Thread and give all info and someone will help you.