Hey everyone. I just recently finished a modified engine swap (the previous engine had the rear stationary gear blown) and as I am only a month into the world of rotaries, I thought I would ask for some help?
I am currently working on 93 FD Rx7 modded with a Greddy single turbo and inter cooler system.
After learning how to NOT flood the engine during cold starts, the problem I'm having right now is that at idle, everything is ok, but upon acceleration, I'm severely bogging down unless I'm lightly holding the accelerator. At full acceleration, the engine bucks and misses, even backfired twice.

Now, I'm new to rotaries and do not have much experience with turbos even. I have an exhaust leak at the front of the manifold. Also, during the swap, I had marked the Crank NE and G connectors, but at some point the marks had rubbed off, and I may have gotten them reversed.
Just wondering what would happen if the connectors were reversed, and if the exhaust leak would affect the turbo/over all engine performance?
Any help would be gratefully appreciated

 

What kind of standalone EMS is it running?

Sounds like it simply needs to be tuned. So it is VERY important that you find a knowledgeable tuner before you start getting on the throttle.

A rear stationary gear is also a very impressive failure. Almost never happens.

Yes, if the VR sensor wires are reversed, then timing will always be wrong. Lock timing with your ECU at -20 and confirm that the pointer lines up to the mark when checking on L1.

 

I'm not sure what EMS it is running, any way I could find out?
Sounds good with the advice of being tuned. I do have a guy in mind, so he'll be looking at it soon.
What's involved with tuning it?
And yeah, that's what I've read about the stationary gear. It was missing 6 teeth and had a large
crack on the end.
I'll try switching the sensors around and see what happens. Would the exhaust leak at the manifold
affect the turbo and boost in any way?

 

Find the ECU (probably in the passenger footwell or glove box) and check the brand.

Exhaust leaks pre-turbo will effect boost, so solve the leaks before the car is tuned.

Tuning involves creating a fuel table across the entire operating range of the engine, creating a timing table in the same way, and then tuning all the corrections to those tables. It's quite an involved process.

 

I found the ECU, its an Apexi(sp?).. the previous engine was already tuned, all i did was put a stock engine in, removed the rats nest, and everything i didn't need to put it in as the old one was. I have new exhaust gaskets coming, confirmed my crank sensor connectors were hooked up right. (white connector on the top, grey on the bottom).

Based on alot of reading i've done, it sounds like the vehicle is in limp mode at this current point. All vacumn lines that are needed with the mod are hooked up, same with connectors.

I'm wondering if the massive leak at the manifold before the turbo would be enought to put it in limp mode? It idles fine, light accelerates fine until 4000 rpm, then kind holds there. If you put hard pressure on it, thats when it bogs. I still have the stock ECU that came with the stock engine when I first swapped it, and I've read about unplugging the battery and pressing the brake peddle 20 times or something?

 

And by the way Aaron Cake, thanks for the help so far.. I'm still very new to the rotary world, and any and all help (and patience! haha) that can be had is very very appreciated

 

Just an update, installed a new set of gaskets for the exhaust manifold, leak is gone. Confirmed cam sensors are hooked up correctly. At this point, engine is still running rich, but I'm able to build boost, but still running like crap haha.

Test drove for 30 kms total tonight at varying speeds. On cold running, car bogs down, misfires, has rare/occasional backfire. Once warmed up, runs pretty good, but still bogging down at higer rpms (when down shifting, its normal.) During my test drive, drives normally on light to medium acceleration without bogging/misfiring, but randomly does it a 25% of the time.

Still running an Apexi ECU, looking to get the stock engine I swapped in with an aftermarket Greddy intercooler and single turbo, with Fastlab fuel regulator and pump installed. Gonna get the ECU tuned sometime next week.

Any comments for what would be making it running rich would be helpful.. Oh, and also noticed its running 45 psi for fuel on idle,and 10 psi for vacumn at idle.. On acceleration, drops to 20 psi vacumn until buiilding boost, then boost gauge rises to 0-3 psi, then jumps to 5 psi (35-4000 rpm, vehicle bogs on heavy accel, normal on light accel), but overall, runs ok on light acceleration..

On edit, i put a stock engine in, and swapped the aftermarket parts over to it, after removing the stock parts before swap.

Any thoughts?

 

I'd just like to mention, that based on what i've read, with an aftermarket ECU, you can't go into limp mode due to its tuning..just wanted to confirm?

 

He already said what you need to do.. have the car tuned.

 

Yeah i know.. Just wanted to make sure i've got all the bugs worked out before the tuning is done. No sense in wasting all that money for them to say something is not working properly.