hanman

86 N/A, no mods, all stock, rebuilt engine with about 12k on it. Running fine, let it set for a few weeks, came back to start it, will not fire.
It cranks fine, has spark.
I have narrowed it down to a fuel delivery problem. I can get it to start (easily I might add) if I spray something flammable in to the intake.
I have good fuel pressure, I tested it. Fuel pump obviously is working. I have power to the one side of the injectors, but, I only tested the secondary. I am avoiding pulling the manifold as long as possible.
I have spark to the leading plugs.

I have tested the following:
Fuel pump
Resistor solenoid
CAS
Secondary injector for power on the one side

I am running out of ideas. What I have left to try are:
Testing the CAS wire to the ECU for continuity.
Testing the main relay.

I am thinking maybe the Main Relay may be faulty. But, I think that is a stretch. The fuel pump was working intermittently when I first started working on it, but I have that fixed. It looks to me like the Main Relay sends power to the fuel pump, AND also to the injectors. Is that correct? The the ECU will open the injector circuit to ground to fire the injectors, correct? So, it's also possible the ECU is bad.

If I have to pull the UIM, and I find out that I have constant 12V to the one side of the injectors, that looks to me like it would rule out the Main Relay.

So to wrap this up: I have fuel to the injectors, but they evidently are not firing. What would cause this?
Thanks,
Dave

rbharris1984

Does it just crank and crank and crank?? Could be flooded. Sounds like what was wrong with mine.

hanman

No, it's not flooded, just the opposite. No fuel to the plugs.

harley71105

If it is not flooded you may have the same problem I had for three years with one of my 88 S/4's. Do a search in the archives for "Intermittent No Start" and you will see my post's over several years. This is how I cured my problem:

The wires coming from your crank angle sensor (CAS) have two shielded connectors. One is about 5 inches from the CAS and the other is an IDENTICAL shielded connector under the brake master cylinder. It seems that over time brake fluid seeped into the connector and in my case caused an intermittent no start situation with all the tell tale signs you are mentioning. Get some spray electronics cleaner, carefully open those shielded connectors and spray the daylights out of them. This could very possibly cure your problem. Let me know and PM me.

hanman

Harley, thanks for the info. You have a bazillion threads on your issue. But while reading them I got some really good information from Hailers.
I am still thinking CAS problem like yours, or possibly a bad ground issue with the ECU.

Everything points to the injectors not getting a signal to fire.
Fortunately for me, my problem is not intermittent like yours, but all the time, as in the car wont' start.