Good evening Y'all,

Just finished a rebuild on a '93 FD, nothing fancy. Just a standard unstack, restack with all new seals, all emissions (valves, air pump, cat, etc), oil metering and double throttle removed . Apexi Intake and turbo back exhaust. The stock sequential twin setup was kept, no changes other than replacing all the vac tubing.

Fires up and runs but under heavy throttle sputters and back fires fierce, running rich as F*** at idle, can't get her over 4500 rpm and definitely doesn't drive well under load.

The more I research it, sounds like the stock ECU just doesn't support running with out all the emissions stuff removed. Is that true? I have an '88 FC 10AE and it ran awesome on the factory computer with all the emissions BS removed.


I hope I didn't get myself into a jam as this is a paid rebuild and undeniably going to have my tail between my legs if I tell the boss we have to buy $1600 in Apexi Power FC plug and play ECU and commander.

MEDIC! I need some help plz!!

Rob

 

with the stock ecu any OMP related isses will put the car in limp mode.... to include unplugging it. so yea.... youll need an ecu. the power fc can be had used for ~600 with the commander. its not so expensive. DO NOT BUY IT NEW. its a senseless purchase. there are so many for sale at any given point that buying new is just an exercise in spending money. like tipping more than the bill because you can..... not because you got great service

 

You need to fool the ECU into thinking some of tje emissions devices and oil metering pump are there for it to run right.

You are in limp mode at the moment.

Look up emissions removal and you will find what you need to do.

I put resistors of the same value in for every emissions device I removed and burnt out the ECU power supply from too much current draw.

Read up more and just put resistors in for the devices that are required and its fine.

 

i dont think the resistor trick works with an omp delete

 

Yep you will need a PFC. The problems you have right now are the ECU being in limp mode with no OMP and with no air pump system the car will idle like crap and on/off throttle will suck.

Stock ECU is really only good for stock cars and VERY minor mods, that's it. Hate to be the "I told you so" but 5 minutes of searching before you went that route would have answered that question.

Even if you tricked the ECU into thinking all those things were there and happy you have a full exhaust on a stock ECU. You will be over boosting and that motor won't last the month.

And, no, you can't put some resistors on and fool it. The air pump gone and OMP gone are dead stops - there is no work around for it.

The other option would be to put the air pump/air control valve and OMP back on then figure out some way to keep boost at 10psi.

Dale

 

A slightly stroked base map on a PFC should be enough. New or used just be sure to get an OLED Commander.
But if a “turbo back exhaust” means a midpipe, a PFC won’t guarantee an overboost situation from creep. Only adding some back-pressure ala putting a cat back in, or wastegate porting will do that.
You may also need a boost controller to avoid spiking with the open intake.

 

No association with the seller but I did just see this….
https://www.rx7club.com/market/1158710