Hey everyone. I just put in a Power FC, and have been working on tuning it (with the help of chucks notes). Up until now the car has been running fine, with a smooth idle and no hesitation. Last night when I went for a spin, the idle all of a sudden was hunting like mad and wouldn't settle. After the warm up time, I took it out, hoping that some driving would settle the idle down. It didn't. Instead the engine wouldn't rev past 4000rpm, and would stumble and skip (alot) at 3000rpm. Even if I clutched it in to rev it up, it still wouldn't pass 4000. This behavior continued for about a hour, and I decided to try gunning it again to see if it would get past 4000, and out of the blue, it did. The hesitation was gone and i could do rev up to 8000, but the idle was still horrible.

I figured it may be the secondary turbo not kicking in, or a vacuume hose leak, but I replaced the stock hoses with silicon ones, and both turbos started working at the end of the night. I also reset the PFC in case and changes i did to it messed with the car.
Other people with similar problems say that it may be a clogged cat, fuel filter or injectors. The cat heat light was lighting up, but that only happened after I put in the PFC, and didn't affect performance.

1992 JDM Fd, Twin turbos, PFC, No air pump, intake, xs power IC, aluminum rad, cat back.

Any help would be appreciated.
Thanks

-Dave

 

When was the last time you cleaned your injectors or replaced your fuel filter?

Dennis,

 

it may be fowlling a plug. fuel filter...a major vaccum leak..lots of little things can generate that.its possible like you said your secondary is no kicking in,...check hose..before we went to a single set up we had ours melt a hose a the second turbo would not kick in...

 

is the map sensor line connected. did you do the sensor check on the commander?

 

Also, tonight after it is good and dark fire up the car and look in the engine bay for arcing. I replaced a harness recently for a customer that had lots of wire insulator missing where the coil harness plugs into the main harness. It was creating all kinds of spark and would run like crap, then suddenly it would go away and be just fine.

 

wont rev pass 4k rpm, and non stable idle, sounds like stuck injector, happened to my as well, try playin around with the injector % to lean then rich with PFC and revvin it, might clear up the jam

 

Thanks for all the tips guys. New fuel filters are in the mail, and so is a midpipe + resonator (in case its the cat). I'm also gonna load up on techron to clean the injectors as well as try lean then rich trick with the PFC. I didn't notice any arcing under the hood, or any vacuum hose leaks (but i'm gonna look closer once i get the manifold off)

Again, thanks for the help.

-Dave