Hey guys, Ive been searching but could not find any answers. I have a 94 FD with full exhaust and greddy intake and a walbro pump. The car starts fine and shows 20 on the vacume gauge. Its when I try to accelerate at any rpms the the engine shutters and bogs down. If I realase the accelerator it idles perfect with no noises. I have also noticed that on the boost gauge it does the hesitation as it approaches 0 psi. It does it if I am in park or in gear. Any help will be great.

 

Do you have a Check Engine Light? Check your boost sensor just to make sure, but I don't think it would idle well if that was the issue. It really sounds like it's in limp mode.

 

How high can you rev up, and are you also limited in MPH? If so your in "limp mode".

 

The cel is not on, I cant accelerate the car at all without it stumbling and wanting to shut off. What causes limp mode in these cars?

 

IF he is in limp mode, it doesn't care how fast your going or RPM. Given enough time, and probably down hill you can do 70 mph in limp mode. It just won't advance timing under load....whenever the UIM looses vacuum.
Certain sensor/system failures recognized by the stock ECU will cause a CEL and put it into limp mode. I'm not certain that's it, it's just the first thing I thought of. You still have the stock ECU.....correct?

 

Yes it does, if in limp mode(safe mode) your limited since you trigger your ecu to keep you below 40mph and when your try to rev your also limited and your car will start to backfire, stumble ect. I know this first had.

 

Sound like what mine is doing, what was your cars issue? I am very familier with mecahnics buy rotaries are a diffrent world to me.

 

Well in my case I reset all the codes and replaced the OMP, now after this I still was in limp mode and there was nothing else that I had that could cause this, so I checked the voltage from the ecu to the omp and ended up being that I would have a 5volt reading but as I hit 4k it wouldnt send back those 5v(1-2v) so I had to redo some wires that were bad and it ended up being one after another, so in the end there were too many damaged wires that I just bought a whole new engine harness, reset the ecu and I was back in business!

In your case check your omp first since this is a very common issue in these cars that throw you in limp mode.

 

Thanks for the info. I will look into this.