Gdalegonalot

My1989 C4 stopped cold 6 years ago while driving. Towed it home. I'm a good mechanic with a lot of tools. No codes, replaced fuel pump, relay and filter. 40psi at the rail. Replaced all distributor components, plugs, wires. Tried a different MAF and computer. New battery. Checked timing, OHMS at the injectors and all ground straps. This summer it started five days in a row, would run for 4-5 minutes and then die. Now, tries but will not start. Most of my hair is already pulled out.

JimLentz

Do you have spark to the cylinders? Are the injectors firing?

aklim

Why did you replace all those things? Timing check is great, Ohm test is misleading and checking grounds straps is great.

HOWEVER, why is it not starting? ASSUMING you have a good fuel pump, you should be getting 40+ psi at the rails when you are doing a WOT run IN GEAR. That will show us that the pressure is holding up under load.

So, when it doesn't start, did you check spark and fuel pressure?

Gdalegonalot

As I indicated in my message, "This summer it started five days in a row, would run for 4-5 minutes and then die"

It ran well on all 8 cylinders, meaning that timing, fuel PSI, injectors, etc., are working as they should. It tries to start, but can't quite make it.

aklim

Meaning it RAN like it should. Till it didn't.

Gdalegonalot

Yup!

aklim

When it fails, test fuel and spark. What is the pressure at failure point? Does it have spark and what quality?

Gdalegonalot

OK, I'll take your suggestion by leaving the fuel pressure gauge hooked up and installing my spark tester before attempting to start the car.