Engine not starting when it is warm outside?

[ericjohnmc]

Hi,

I would appreciate any help that I can get on this issue. I have a 1994 s-10 Chevy Blazer with a v6 engine. My issue is that my car doesn't seem to start when it is warm outside. It seems that the fuel pump is not making any noise when I turn my key to the on position. After giving up on the car yesterday and leaving it at work, I drive in this morning with another vehicle...and Bingo...the Blazer starts this morning. I can hear the fuel pump turn on before starting. So, I am pretty sure it is the fuel pump acting up. Is there anything that anyone can think of that would cause the fuel pump to work > not work > work again? I did have the fuel pump replaced about 4 - 5 years ago. The vehicle has 120k miles. Is there anything that I can check before replacing the pump? Thanks for any help!!!

Eric

[Mikado14]

Yes, you can check the fuel pump relay. I believe it is located on the fire wall above the master cylinder.

[ericjohnmc]

Thanks for the info Mikado14. Do you have any info on how to check this relay? I will do some google searching on it. Is it just something like using a voltage tester to verify it is working? I will see what I can find, but I appreciate your response.

[BlazerLT]

Best just to replace it.

Is your engine the CPI or the TBI injection?

[ericjohnmc]

How can you tell which fuel injection it is? I just walked out to my car and searched every part around the fuel injection and could not see if it is CPI or TBI.

Thanks for responding!

[BlazerLT]

Does it have the round intake kinda like a carb?

Or does it have the orange VOTEC plate on top of the engine.

[ericjohnmc]

This Blazer has the Vortec plate on top of the engine.

I am going to get the fuel pump relay tonight and put that in after work....and hopefully this will end the issue. Car started and ran fine yesterday...but has done this three times where it won't fire, but turns over just fine. A few hours later it is working again.

I appreciate all the help you guys have given me!!

[BlazerLT]

AHA!

Remove the upper plenum cover and check for fuel leaks in the fuel injector and internal fuel lines.

Chances are the fuel pressure regulator on the injector is leaking.

[ericjohnmc]

Thanks for all the help BlazerLT. I will check that out tonight. I didn't have time to replace the fuel pump relay, but for sure will on my days off starting tomorrow. Since it is so cheap, might as well put a new one in....and also will remove the upper plenum cover and check like you said.

I appreciate the responses a lot. Thanks!

[BlazerLT]

Please take photos of your upper plenum off so I can diagnose.

Also remember to use a fresh gasket when you put the cover back on and remove the old one completely.

[ericjohnmc]

Ok will do. I have a digital camera, so it will be no issue taking some photos.

I will post back once I have done this. Thanks!

[BlazerLT]

sweet! and make sure they are in focus.

Check this link out for hints on photos and remember to clean the EGR port out while you have it off.

http://www.s10forum.com/forum/showth...pi+replacement

[Mikado14]

What I am about to type is serious and no sarcasm.

If the original post says that the pump is not running when the key is turned on, how can the problem be the regulator inside the plenum?

Please explain.

[BlazerLT]

wups, I help so many now I forget what thread I am in.

In this case I can almost guarantee the fuel pump has gone out.

Never yet have I heard of a relay going bad.