weez58

I've been chasing a no start problem with my '86 951. First it was no spark. After bypassing the alarm, changing speed and reference sensors and their harnesses it turned out to be a DME problem. I had that fixed. Now I have spark, fuel pressure is 40+psi, noid light shows pulsing at all four injectors, still no start. I can get it to run with starting fluid, but only until the fluid is gone. It acts like no fuel.

Any ideas?

Humboldtgrin

Bad fuel.

weez58

New pump and filter. Flushed the old gas out and replaced with new. To your point, maybe I didn't flush it well enough. The plugs looked totally dry.

GJB928

I'd pull the fuel rail and have injectors fire into jars to see what is happening. If they don't spray, try them individually with a battery. Be careful with spark and fuel though.

Tom M'Guinn

I'd check the resistance across each injector, and check the harness for frayed wires under the connectors. If any of the injector leads get shorted (in the harness, which is common, or in an injector), it can act like a bad Christmas tree bulb and prevent any of them from firing. The noid light should reveal this, but it depends on how things were hooked up when you tested. Other than that, I'd look to physically (and safely) look to see if fuel is getting in there. Pulling the plugs and cranking is usually good enough to see/smell raw gas.

weez58

Thanks for the input, I'll check these things out.

Paulyy

From experience, If the injector harness gets shorted, it'll shut off the DME until you turn off the car and back on. If it stays shorted, your car will not start at all. You can check with a Noid light, i used a generic LED and noticed it was still flashing when the harness was shorted. But it wasn't as bright.

Also if something else gets shorted that goes to the DME, it'll most likely shut it off also.

weez58

Pauly,

If the DME shuts off, would you still get spark?

Thanks for the input.

-Bob

weez58

Solved. I sent the injectors to Fuel Injection Corp. They cleaned and tested them. After 20 years it rumbled to life!

Paulyy

Sorry mate didn't see your reply. Glad you solved it.

But to answer your question. From memory, yes it should still spark. Because when i was having issues, i checked the spark and it was sparking. That's how i ruled out the ignition system.