Hello,

I just recently purchased a 93 FD not running with a new rebuild that had never been started. The person I bought it from said it had a fuel leak and that he couldn't figure out where it was coming from.

I get the car home and go ahead and try to start it. The car runs for about 6 seconds then dies. I decide to locate and fix the fuel leak before I start it again just for safety reasons. I jumper the fuel pump on and start looking for leaks. I had the intercooler off at the time and I smelled a HORRIBLE gas smell, but I didn't see anything leaking! All the sudden gas started POURING OUT OF THE UPPER INTAKE!!! It turns out it was a damaged o ring on a secondary injector. Once that was fixed, the car ran great.

I had just completed a full non sequential conversion and was planning to install a
Power FC once I got the car in good running condition.

Since it was running great, last night I installed the PFC exactly per the diagrams on the forum. I turned the key on, and the screen on the PFC never displayed anything. I thought that was odd, so I went ahead and tried to crank it. It sounded hydrolocked as the starter was having a hell of a time turning the motor over.

I took off the intercooler and it was FULL OF GAS AGAIN.

What the hell!

To sum it up:

Car was running perfect.
Installed the power fc, screen never displayed with the ignition on.
Tried to crank it but engine was full of fuel again.

Why would the power fc turn on the fuel pump and open the injectors?

Screwed Power FC? If so, to run with just the stock ECU would I have to reconnect the wires I cut for the PFC?

I previously owned an LT1 FC and wanted to get back into the rotary game. This isn't a good way to treat an ex V8 guy. I'd hate to put an ls1 in it... :p

Thanks,

Brando

 

karma is a bitch, haha!!

I have no clue what your issue could be...if it worked without the PFC, I'd start there.

 

Sounds like you shorted your power fc. Take it apart and look for a burnt section on the printed board. The short may be keeping one or more of the injectors stuck open.

Unfortunately powerfc's only come with a 30-day warranty so you're sol as far as that's concerned. The stock ecu for a while until you get a replacement would work, the powerfc may be repairable if you can find someone local who can repair that burnt segment.

 

oops nevermind.

Dave

 

I figured it was probably a toasted PFC.

Soooo.... the question is, do I have to re solder the wires I cut to install the PFC if I were to reinstall the stock ecu? It was just emissions crap, right?

I'm not concerned about the check engine light being on, I'm just worried about the stock ECU going into limp mode.

I'm planning on buying the resistors for the solinoids I removed tonight since I got rid of the 33 feet of bastard vacuum lines....and now I have to put the frekin stock ECU back in.... grrrrr

Thanks,

Brando

 

Just make sure to install the resistors if you are going to run the stock ecu or it will go into limp mode. Im sure this is something you know but just making sure.

 

Thanks the responses!

The only question I have left is if I have to reconnect the wires I cut to install the PFC in order to reconnect my stock ecu, and if I don't reconnect the wires, will it go into limp mode.

Thanks!

Brando

 

Here are the 4 wires that you cut for the PFC:

3J = EGR switch (Ca only)

4F = split air bypass solenoid

4O = EGR solenoid

4P = AWS solenoid

 

why did it short out? if you dont figure that out, why isnt it going to fry the stock ecu too?

 

The power fc was purchased used, and the person I bought it from had bought it from someone else and never verified that it worked in the first place.

I think the PFC was shorted out before I installed it. The car was running PERFECT when I removed the stock ecu and installed the PFC.


Here is the wiring diagram I used to install it:

https://www.rx7club.com/attachment.p...d=179938&stc=1


The question of the day is:

Thanks,

Brando

 

ttt

 

you will just get check engine light when connecting back the stock ECU. Not going to prevent your car from running properly.

Reza

 

Thanks man!

 

On the Diagram it shows a pinout 4C and a 3M, those are for the Knock sensor(white wire) and I believe the black wire is for your injectors. Those shouldn't be cut. Maybe this is where your problem is. I would re-splice those two connections and see if your PFC comes on. If it does then there was your problem. You then will probably have to clean your plugs and crank over the engine to relieve it of the excess fuel before you try to start it again.

 

FSM says:

4C.....Ground (CPU).
3M.....Knock sensor.

 

I'm gonna throw a big thanks to the ******** that made that diagram.

Thanks to everyone else to noticing this error for me!!!

I'll let you know what happens tonight after I reconnect the wires..

Thanks!

Brando

 

4C=CPU ground, that would be the reason why the Comander wasn't lighting up.

 

4C=CPU ground, that would be the reason why the PFC Commander wasn't lighting up.

 

http://westpenn.rx-7.org/ApexiPFCpinout.htm