jimmydriver

I have a mechanic with 45 years of experience completely stumped. The vehicle has a new ICM, EGR valve, distributor cap, rotor, fuel pump, another new fuel pump, fuel pressure regulator, battery, positive battery cable, we've tried 3 different computers, 3 different spiders, and a lot of foul language. Drive it to the store, shop, come back out and try to start it and sometimes it won't start without starting fluid. It never stalls but sometimes it idles rough. Any ideas?

mountainmanjoe

at least you know it's fuel related. Is it making good pressure? Is the filter inline or in tank. Lines could be rotten.

jimmydriver

Filter has been replaced with the pump. Pressure has been checked often.

Gumby22

When the hard start condition is present, before using starter fluid, does it sound like it’s trying to start, or does it just turn over?

jimmydriver

It cranks but that's it. It almost always happens after I drive it and it's warm.

Gumby22

Being a 1995, the OBD1 system would only be monitoring for basic faults so I don’t think it’s likely that codes will help with this problem, but check for them anyway, especially if the SES is on.

Whether or not it has useful codes, try testing the EVAP purge valve using either or both methods below.

1) Engine warm, but off, disconnect the canister side of the purge line and attach a vacuum gauge to the valve. Run the engine and check for idle spec vacuum (15-18 in*Hg) with the purge valve plugged in** - if present, unplug valve, purge the vac gauge line - recheck - any vacuum with the valve disconnected means it’s not working. Verify power/ground current flow with a 9000 series headlight in place of the valve - very bright = good circuits. Replace valve and re-evaluate hard start with functional EVAP system.

**EDIT: You may have to manually jump the solenoid to direct power and ground to open it - I can’t recall, at the moment, if the 95 models commanded purge at idle. If not, the light bulb test won’t work at idle, either.

2) Just unplug it for now. If the problem persists, remove the valve and cap the vacuum port on the intake. Hard start next time = good valve. Look for a different source.