TrianglePiston

I just installed a PFC that I purchased brand new. My ’94 FD is all stock except for a Pettit downpipe and has 32K original miles. I’ve had the car since January, and this site has been very helpful so far. But this is my first post asking for help. I have searched and could not find another post with a scenario like this. I have also read both the PFC FAQ and the ECU manual, and followed the installation procedure very carefully. The car ran fine before the install except for the 3k hesitation (which I was hoping to eliminate by installing the PFC).

When starting the car after the install (it was a cold start), it ran around 900 rpm and ran very rough. I know the car is supposed to run rough when you initially start it, but it never smoothed out one bit for the full 30 minute learning period. As the car warmed up it ran between 600-800 rpm. Even after the 30 minute period, the car was not drivable. I have adjusted the idle bleed screw to no avail. And this is more than just an idle problem as it runs badly at any rpm when you rev the engine. And yes, I have cut the proper wires. I do electrical work for a living, so I am confident that this was done correctly. I also reconnected the ground wires that were attached to the factory ECU and the “Control Unit” for the cooling fans. And there was no Check Engine light ON at any time.

When running, there was a light hint of black smoke from the exhaust. I know the PFC has a base tune that is rich, but I was not expecting any black smoke and was certainly expecting the car to be drivable.
And I have also verified that the PFC is the correct model # for my car.

Any ideas? Any help would be greatly appreciated.

SonicRaT

iTrader: (6)

Have you reinitialized the PowerFC and reset everything to the default values?

TrianglePiston

Well, I put the stock ECU back in for troubleshooting purposes, and car still runs the SAME with the stock ECU! Darn! Now I'm really in trouble.

I re-connected all the wires that were cut when I re-installed the stock ECU. I really have no idea why this is happening. During the PFC install, I removed the air tube going to the TB to get at the Idle bleed screw, but it was already out 1/2 turn to begin with. I put everything back the way it was very carefully. Is there something else that could have come loose while taking off the air tube? It was just 4 nuts and hose connected to the side of it. Could a blown fuse cause the car the run like this? I did a quick check on some fuses under the hood and they look fine.

I'm uploading a video and I'll post a link so you can listen to it. Hopefully someone can give some insight after hearing the car run. The video is right after installing the Power FC, but currently with the stock ECU back in the car, it still runs like it does in the video. Let me know what you think.

Thanks in advance for your help.

TrianglePiston

Here's a link to the video

FD Running very rough with Power FC or stock ECU installed - YouTube

Banzai-Racing

iTrader: (11)

Sounds like you knocked the hose off the map sensor when you were messing around with the intake elbow. When the car is running what is the boost reading on the commander?

TrianglePiston

I really really hope that's the problem. I'm going to check that when I get home from work. That would make the most sense since the problem remained after reconnecting the stock ECU. We shall see...

TrianglePiston

Yep that's the culprit! Thank you very much! As soon as it stops raining, I'm going to fire it up and take her for a spin with the stock ECU just to make sure she's still in good running order.

My only concerns now are:

-Do you think it hurt the engine to run without the map sensor hose? After I originally installed the PFC, I let it run for about 30 mins for the learn process. I read that it's supposed to run rough on the initial startup, so I thought it was behaving like normal.

-I started the car last night after putting the stock ECU back in (and the map sensor hose off), but had to shut the engine off right away because of the fumes and it was running like crap. It was a cold start, so I hope the engine did not flood. Do you think the plugs will still be ok?

cewrx7r1

iTrader: (2)

Hopefully you learned something from this.
Operator error causes many so called weird problems.