84 GSL-SE (EGI)

This morning on the drive in, the engine would intermittently kick into a cycle of reduced power, regular power, reduced-power about 3 or 4 times a second. lt happened at all RPMs, and went to low power mode for an extended period at one time.

There has been no mechanical work done recently, and when I popped the hood I could still get it to do it at curbside just by pulling the accelerator cable...

I assume this is a vacuum problem or a sticky valve (hope its not the comp), but I have no idea where to start looking.

Any thoughts?

 

It's a rotary, there are no valves. Vacuum problem maybe.

 

I thought there were some vacuum activated valves that adjusted what happened with the EGI, is that not the case?

I've tried looking through the archives, but the problem with any search I've done is not too little info, but toom much.

If you know you've participated in a thread discussing this before, please respond so that I can use your name to filter the results a little further.

Any help appreciated!

 

There are indeed. The air control valve and bypass air control valve for example.

You're problem doesn't sound familiar, but it might be in the description. You mention the reduced and then regular power happens at all rpm, but do you feel it only in first and second gear? (that is, low speed) If so it's likely the TPS that is out of adjustment.

Offhand, I wouldn't think the valves or a loss of vacuum are the problem.
The ACV and BAC affect the idle, not the power when you are moving and at higher rpms.
Vacuum leaks, depending upon how bad and where they are will cause anything from a high idle, bouncing idle, or no idle. But even if it's bad enough to stall at idle, it can run decently when you are driving at 3 or 4k rpm, unless it's major which doesn't seem to be the case for you.

What does the rpm do at idle when you increase the rpm? I gather it bounces, but from 800 to 1500 or from 800 and drops to near stall then recovers, or...
How is the idle if you do not touch the throttle?

"went to low power mode for an extended period at one time. " My first thought is a dirty fuel filter. When were the fuel and air filters last changed? Also, do you use injector cleaner in the gas?

If you have not done so recently, I would clean and oil the throttle linkage. The secondarys sticking open will cause all kinds of grief.

The TPS or fuel filter would be my guess for now. If it was happening at low speeds and idle, TPS. If it happened at high speed also, fuel filter. More detail may point to something else, but that's all I have for now.

-John

 

Just found the gremlin!

Their is a secondary wire from the front ignition coil that I assume is tied in to the EFI system. It was "broken" inside the insulation. I found it only because it was causing stalls more and more regularly.

Also, although I knew it wasn't flooded, the "flood restart" procedure of taking off the main lead from the front ignition coil WAS getting me going again, 4 times out of 5...

Eventually figured out it had to be something else I was touching...

Took a few volts through my system to get it to "stall" for me, but boy was I happy to take those volts if that's what it took to kill the gremlin!

<insert happy dance here>

 

Good for you!
Intermittent wires and connections have got to be the hardest problem to trace.

The wire on the front coil is indeed tied to the EFI system. It tells the ECU the engine RPM. If the ECU does not detect it's signal, it will stop the fuel pump.
Which, of course, is why disconnecting it will unflood the engine.

Nice gremlin kill.
-John.