Stranded with no spark - 86 328

Good to hear you got it started. And quickly too.

So, it would crank but no start. Not even a stumble i.e. no light off at all until you pressed the flap? I'm leaning towards the fuel accumulator but it was already getting [some] fuel...

 

I was there assisting this AM..

It was as if the fuel was vapor locking in the fuel distributor in a not warm/not cold condition. I had this happen in my 928 a couple times. When we depressed the air plate on the fuel distributor, it added fuel to the injectors and the car would start.

Warmup regulator with an incomplete mixture? Cold start valve not adding enough fuel to get a start cycle to pull down the sensor plate in the CIS distributor?

 

On my 328 GTS (Euro version) car in a warm/cold situation the engine is sometimes flooding. It happens on taking in gas after a two mile drive at the gas station. It won't start. Happened two times.
After disconnecting the coldstart injector it would start again on full throttle.

Maybe you have the same situation. Pushing the regulator plate down will add more air to the mixture so the mixture becomes less rich.

Since one year now I disconnected the coldstart injector and never had a starting issue again. Even cold start is fine without it.

 

That's what I was thinking, with maybe a leaking cold start injector which is flooding the intake.

 

(I assisted some as well - if you count 'pushing' as 'assisting'. LOL)

It was strange, because at first, we could smell fuel, but had no way to test for spark, so David checked the fuses/relays as described in the original post. Curt immediately thought it was a fuel issue from our description, so he suggested (and performed) pushing on the air sensor plate, and voila - it worked.

But now - reading through the various replies here, I'm confused. Does pushing down on the diaphragm create a *LEAN* condition or a *RICH* condition???

~Matt

PS
We should have tried unplugging the cold start injector. Didn't think of that at the time.

 

Rich.....very rich.


Your statement about vapor locking is very possible. This crap we are being sold as a substitute for gasoline vapor locks easily. That cars defense against that is residual fuel pressure and if that is lost vapor lock is often the result. It can be other things too but the good news is CIS is one of the easier fuel injection systems to diagnose.

 

MicroPlex ignition has many places where a single failure can take out both banks of spark. I'd confirm/deny spark during starter cranking before deciding what to do next -- JMO.

 

What Steve said.

It takes compression, ignition and fuel to make it run. Narrow it down to one of the three before focusing on individual components.

Spark is very easy to confirm. Get it out of the way.

 

Sometimes these cars always smell like fuel... though after I redid my fuel likes with the kit from SRI mine doesn't smell so strongly.

This is all to say you may smell fuel but you aren't getting fuel. Do you hear the pump running when you turn the key to the "on" position?

 

Just for fun, I will place a bet on a failed crank position sensor.

 

Thanks for sharing David. The little connectors inside the multi connector need a tight fit to avoid building resistance. The copper wires also have to be treated with a form of corrosion protection spray.