retiredone

42 psi fuel pressure, runs on starting fluid, cranks but no start. Help

Silver85

I would focus on the injectors. Use a noid light to test them and see if they are firing. You can ohm them as well to see if they are still electrically sound. CHeck to see if they are getting the pulse signal from the ECM.

retiredone

Thanks, I will look in that direction.

corvetteronw

Google "L98 starting sequence". So you can properly diagnose before throwing parts at it.

retiredone

Notes on the c4. Car had been sitting for 5 years in garage. Absolutely show car clean. Battery completed dead. Fuel pump was not running. Replaced battery,fuel pump and filter. Noid tested injectors, firing both banks. Car runs if gasoline squirted in intake. Appears fuel injectors are gummed up. Anyone have any advice? Would it be possible to use a cleaning kit at fuel rail to get it going or replace injectors? Car is very clean less than 4000 actual miles. My first Vette.

aklim

Are you saying it starts and keeps on running after start if you spray gas in the intake?

If the injectors are bad, I wouldn't bother to rehab them. Get a tested set from FIC that are reman. https://fuelinjectorconnection.com/c...3-injector-set

They are probably Multecs and not designed with Ethanol in mind.

Silver85

Don't waste time trying to clean them. You might get them good enough for the car to run but never back to factory spec IMHO.

4000 miles! Wow. Post some pics. That sounds like an awesome find!

retiredone

I appreciate your comments. I got the car started just a few minutes ago. Every injector was stuck closed. I disconnected them all electrically. I made up a fused jumper wire directly from the battery. Tried applying power with no result to first injector. I then tapped on the injector and reapplied power. Heard the injector activate. Cycled several times with key on. Each injector came to life. Car started on first crank. Idled rough and then cleared up. I will try her out and go from there. The car is black on black all original. I'll post some pictures a little later when I figure out how. Thanks everyone.

aklim

Every injector will be closed or fuel will pour into the chamber. IIRC, it is in a constant "hot" state and when the ECM fires it, it grounds the circuit and "ungrounds" it to stop a millisecond later. Since you tapped it and it fired up, I suspect that your problem is that when you start the car, the vibration will rattle the injectors to be equivalent to the tap and the car runs.




Which do you have?

retiredone

Have the Multec. It is starting and running now. I will probably replace them in the near future. Do you know the specs as far as flow and do you have replacement recommendations?

Silver85

Call FIC (link above in previous post). They will set you up.

81c3

I bet after you change the fluids, do a good safety check and condition check of all rubber parts.... and put a few miles on it, it will run fine. I have 35k miles on my original multecs... car runs near perfectly. That said, I do plan on a swap this winter just for preventative maintenance sake as well as a chance to replace the EGR valve and FPR along with any questionable vacuum lines etc and of course new gaskets never hurt anyone....

aklim

Dump them.

retiredone

1991 c4 3680 miles.

She seems to be clearing up quite well. I give her a chance before swapping injectors. Adding Lucas injector treatment as we go. Thanks again.

JimLentz

That sure is a sharp looking car!

I recently replaced the factory Multecs on my '92 with the Bosch from FIC. Even though the car was running fine I figured with 43K miles with much of that being exposed to ethanol it was a good choice. I found the resistance on one of the injectors was about 1/4 of what it should have been. The ethanol was "eating" away the insulation on the coil and eventually it would have blown the fuse for that bank. Anyone want some old Multecs?

aklim

A little snake oil will perk it right up.

billschroeder5842

Great Car!

Your beast will awake slowly, but awake it will.

Driving her is the best medicine you can can give.

NavAir

After 26 years, those Multecs deserve to be put out of their misery. If you ever actually drive the car , you will likely have it die on you when it gets hot, due to one or more of the Multecs shorting out when hot. That is what happened in my 1989.

Steve

aklim

Either make trap targets out of them or beat them with a hammer. 8 injectors, 4 and 4 maybe? People buy snake oils because they are cheap enough they can afford to try a "Hail Mary".