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Throwing 13 Error Codes in 1993 FD3S. Backfire/Sputtering under throttle/load
Hey guys. I imported a JDM 1993 FD3S (Series 6) a few months ago. It has a 1996+ (Series 7) engine swap in it running off of the 1993 Series 6 ECU and wiring harness. The guy I bought it from in Japan said it was only throwing code 44 & 45 and that it was running fine until the ECU picked up the codes. Well, I just pulled the codes myself and it’s picking up the following:
25 - Solenoid Valve, pressure regulator control - open or short circuit
26 - Metering Oil Pump Stepping Motor - open or short circuit
31 - Secondary Air Bypass Valve - open or short circuit
32 - Secondary Air Switching Valve - open or short circuit
33 - Solenoid Valve, port air bypass - open or short circuit
34 - Solenoid Valve, Idle Air Control - open or short circuit
40 - Solenoid Valve, Purge Control - open or short circuit
42 - Solenoid Valve, Turbo Precontrol - open or short circuit
43 - Solenoid Valve, Wastegate Control - open or short circuit
44 - Solenoid Valve, Turbo Control - open or short circuit
45 - Solenoid Valve, Charge Control - open or short circuit
46 - Solenoid Valve, Charge Relief - open or short circuit
50 - Solenoid Valve, Double Throttle Control - open or short circuit
It looks like a lot of it has to do with the turbo system. I removed the UIM, pulled the Solenoid Box(Rack), and tested them all, they all seem to be good. Although I must mention, the wiring to the solenoids is TERRIBLE. It looks like the previous owner cut all of the solenoid connectors from the Series 7 rack and merged them with the Series 6 harness using some kind of shoddy butt connectors.. Should I test them for continuity or something(is that how it works?)? Please excuse my ignorance, I know next to nothing about wiring and electrical connections. The car has been in “limp mode” since I got it. Apply 30% throttle and all it does is backfire and sputter, but it can rev up to 5k rpm if you throttle it gently. It can drive up and down the road but not with any reasonable throttle/load. Would somebody mind pointing me in the right direction? I’m not really sure where to go from here. I’ve done basic maintenance like plugs, wires, fuel filter, oil, etc. but clearly that’s not the issue here. Any help would be much appreciated!
A guess is that the previous owner was running an aftermarket ECU of some sort that would ignore most, if not all those codes and just removed it before sending it off to it's new home half a world away.
I'm not sure about all of them, but the OMP/MOP code #26 is one that for sure will put you into limp mode (fuel is cut and timing won't advance if the manifold doesn't see vacuum).
Since you have accessed at least some of the wiring carnage, I'd suggest cleaning it up as best as you can with good wiring, soldered joints and wire shrink. Then wrap it in some good self-sealing silicone tape before putting it back together. If you can't do that yourself, find someone to do it for you. Then purchase an aftermarket ECU. Apex'i PFC is probably the least expensive these days. I recommend NEW PFC....you don't want to buy yet another headache. Make sure it's for the JDM models. $1000-$1200 is a guess with the latest OLED Commander screen which is what you want. It's pretty much plug-n-play with the stock ECU. That should get you out of limp mode and at least able to drive the car.
Start the car, then rev it a bit and Key off key on before it stalls. Should take it out of limp mode. Get some 2 stroke oil in the tank because you don’t know if your omp is working and see how she drives.
A guess is that the previous owner was running an aftermarket ECU of some sort that would ignore most, if not all those codes and just removed it before sending it off to it's new home half a world away.
I'm not sure about all of them, but the OMP/MOP code #26 is one that for sure will put you into limp mode (fuel is cut and timing won't advance if the manifold doesn't see vacuum).
Since you have accessed at least some of the wiring carnage, I'd suggest cleaning it up as best as you can with good wiring, soldered joints and wire shrink. Then wrap it in some good self-sealing silicone tape before putting it back together. If you can't do that yourself, find someone to do it for you. Then purchase an aftermarket ECU. Apex'i PFC is probably the least expensive these days. I recommend NEW PFC....you don't want to buy yet another headache. Make sure it's for the JDM models. $1000-$1200 is a guess with the latest OLED Commander screen which is what you want. It's pretty much plug-n-play with the stock ECU. That should get you out of limp mode and at least able to drive the car.
Yet also not the worst purchase. I paid $8500 for the car prior export expenses. I bought it for resale, so as is, I might be able to maybe even make some money off of it.
I don’t think the previous owner had a PFC on it, although it’s possible. He installed coilovers for me free of charge just so I could raise it high enough to drive on to the boat, seemed like a nice honest guy and disclosed the issues in the ad (not sure if there were actually only 2 codes at the time he listed it or not though). Yeah, the OMP will definitely throw it into limp mode, along with some of the other codes I’ve listed. But the sheer amount of codes it’s throwing leads me to believe it’s a short in the wiring or some kind of wiring related issue. I find it hard to believe that almost everything that has to do with the turbo system is bad. Especially when I tested the solenoids and they’re good. I also had the idea that a PFC would be the answer to all my problems, but I found the same suggestion from the gentlemen who commented below you in another thread, to rev the car up and turn the ignition off and then on before the motor could turn off to bypass the limp mode, and it didn’t work(this has worked for other people). The car would still sputter and backfire after trying it multiple times.
Originally Posted by 97fd3s
Start the car, then rev it a bit and Key off key on before it stalls. Should take it out of limp mode. Get some 2 stroke oil in the tank because you don’t know if your omp is working and see how she drives.
Unfortunately, I saw you recommend this to someone in another thread, I tried it myself and I’m still stuck in Limp Mode. Although, I never put 2 stroke oil in.. regardless, took it up and down the road, still sputters/backfires above 30% throttle. Tried revving it, ignition off then on several times to bypass limp mode, same thing. Even just revving it in my driveway above 30% throttle it sputters/backfires. Although, if I rev it gently it will go up to 5k rpm. But yeah, the problem remains. Stuck in limp mode.
It the OMP isnt working and you dont have 2 cycle oil in the gas tank you are going to have an expensive paper weight if you keep running it.
2 cycle oil is the same as premix, right? I bought some Idemitsu premix and threw some in when I first bought the car, but none on this current tank. I’ll be sure to put some in. Don’t suppose a little white smoke on cold starts would be the result of not premixing? Or is that fairly normal?
Yea same thing. No oil in the combustion chamber will accelerate wear, its a necessity. I have a working OMP and premix half ounce to the gallon. Without an OMP you will want to increase that mixture but I cant remember whats recommended.
As for your issue, id probably take what the previous owner said with a grain of salt. Post some pictures of the wiring issue, look through the FSM and make sure all the wires are where they need to be. Check for grounds, etc. The ECU’s and wiring were quite a bit different on the 96+ from my understanding.
Yea same thing. No oil in the combustion chamber will accelerate wear, its a necessity. I have a working OMP and premix half ounce to the gallon. Without an OMP you will want to increase that mixture but I cant remember whats recommended.
As for your issue, id probably take what the previous owner said with a grain of salt. Post some pictures of the wiring issue, look through the FSM and make sure all the wires are where they need to be. Check for grounds, etc. The ECU’s and wiring were quite a bit different on the 96+ from my understanding.
Yeah, I’ve read you should always premix (stupid/lazy me for not doing so, I know). Interesting you say 1/2 oz per gallon, reading briefly online guys are saying 1oz per gallon. I’ll read up more on it later.
Yes, I’m coming to find I should have taken diagnostics into my own hands in the first place rather than taking his word for it and throwing money at the car.. 13 error codes later. I heard JDM manuals aren’t the easiest to find but I’ll search around. I’ll check for grounds when I get home from work. I’ve read the Series 6 and Series 7 are relatively similar, yet different. Different plugs/pin outs, but both run an 8 bit ECU. I don’t have a very great photo of the bad wiring, but here’s one I took a few months ago. You can kind of see connectors. When I was putting the Solenoid Box back in the other day one of the connectors disconnected while gently handling the wiring. They’re definitely not secured well.
Thanks for the info. If the OMP is bad I’ll probably just delete it and premix(if I don’t just end up selling this headache as is).
Also, good to know. I’ve yet to do a compression test. The smoke doesn’t smell sweet, it just smells like the car is running really rich. The smoke goes away after a few minutes. It’s also really cold in Washington right now, not sure if that might have anything to do with it.
Sounds like you have a frankenstein. JDM control system. USDM harness, ? ECU.
You could search the forum on converting a JDM to USDM, but it may be easier to just pick one (JDM or USDM) and make everything consistent all the way from the ECU to the wiring harness to the controls). Once it's all consistent, it will be much easier to troubleshoot any problems.
Sounds like you have a frankenstein. JDM control system. USDM harness, ? ECU.
You could search the forum on converting a JDM to USDM, but it may be easier to just pick one (JDM or USDM) and make everything consistent all the way from the ECU to the wiring harness to the controls). Once it's all consistent, it will be much easier to troubleshoot any problems.
Hope you sort it out before flipping it
It’s very much a Frankenstein haha. Very overwhelming car for my first Rotary. I think I might just be better off selling it and importing something cleaner. It’s already been sitting for months. I could have had this one sold and another one here by now. I’d imagine this would sell fairly quick, not 100% sure what to ask for it though.
Just buy an Apex’i if you wanna keep the twins Sequential or a Link if you don’t. Don’t waste any more effort on the stock ecu. Get the plug in for whichever ecu connectors you have and just go through the harness. Once you’ve taken out all the solenoid wiring and the omp wires there is not much left. Also your harness won’t be as crispy as the lhd cars as it does not go anywhere near the exhaust.
The link g4+ is a great ecu for the money. Basically the same as the Vipec that Mr Coleman is so fond of.
here are the pin outs for both the 8 bit and 16 bit ecu’s courtesy of cough cough adaptronic.
...The smoke doesn’t smell sweet, it just smells like the car is running really rich. The smoke goes away after a few minutes. It’s also really cold in Washington right now, not sure if that might have anything to do with it.
If it’s not accompanied by a sweet smell and a rough idle it maybe normal then...just steaming off condensation. I didn’t consider that as it hadn’t been that cold here in the Midwest...yet.
Just buy an Apex’i if you wanna keep the twins Sequential or a Link if you don’t. Don’t waste any more effort on the stock ecu. Get the plug in for whichever ecu connectors you have and just go through the harness. Once you’ve taken out all the solenoid wiring and the omp wires there is not much left. Also your harness won’t be as crispy as the lhd cars as it does not go anywhere near the exhaust.
The link g4+ is a great ecu for the money. Basically the same as the Vipec that Mr Coleman is so fond of.
here are the pin outs for both the 8 bit and 16 bit ecu’s courtesy of cough cough adaptronic.
You’re the man, thank you for that! Only thing is, what if swapping out ECU’s doesn’t bring it out of limp mode? I’ve read of people experiencing similar issues to me even with a PFC. And I haven’t been able to find any threads with anyone throwing as many codes as I am. I thought for sure the ignition on/off trick would have bypassed the codes but that doesn’t seem to be the case. I guess I’m just scared to fork out 1.2k on an ECU just to have it not fix the problem when I’ve already spent $800 trying to fix a car I’m just going to sell anyways.
If it’s not accompanied by a sweet smell and a rough idle it maybe normal then...just steaming off condensation. I didn’t consider that as it hadn’t been that cold here in the Midwest...yet.
The idle seems pretty good to me. Then again, it’s my first Rotary. Not sure what a healthy one should sound like. But yeah, it just smells rich. Although, today I noticed there was a bit of what I assume to be water in the muffler after starting it. Probably just condensation.
Most of those solenoids all share the same power, it’s just branches out in the harness.
Sorry for the late reply, been considering my options. Yeah, I heard the share the same wire/fuse. I don’t know how to, but I’ll try to figure out how to test to make sure they’re good. I feel like it has to be that considering literally all of them are throwing codes. Ideally I’d like to do this as cheap as possible since I’m just selling the car. In the worst case, I’ll just pick up a Standalone, cheap exhaust manifold, Holset turbo, etc. go single and delete all of the emissions/turbo control stuff.
Please ignore my previous comment. I can be a bit of a moron. For some reason, I was under the impression that I needed to retain some of the solenoids in order to run the stock twins. Upon some research, I’ve decided to go non-sequential (poor mans) and delete all of the turbo control and emissions solenoids. OMP, Wastegate/Turbo Control, FPR, pretty much everything I’m throwing a code for. I have a boost gauge, manual boost controller, and Power FC I’ll be installing once the Power FC arrives this coming week. I got the Power FC for $890 USD shipped brand new from Black Hawk Japan. If this doesn’t solve my problem, I don’t know what will. Also, I found two 60 amp fuses in place of a 30 amp fuse & a 40 amp fuse. As stated prior, I don’t know much about wiring, but I read online that running higher amp fuses than recommended can result in a wiring short. The fuses belong to the “b2” and “EGI” slots. Do these circuits run with the solenoids? Is it possible that this damaged my solenoid harness? Thank for all the advice.
I’ve already thrown $900 at it doing maintenance and throwing parts at it to try to fix it. Might as well spend another $900 to get the car driving good to make more money than I would selling as is. Assuming the wiring is bad, I can’t just wire in resistors and use the stock ECU, so Power FC it is. Worst case, it doesn’t fix the car, I sell the Power FC, get most of my money back and sell the car.
u must have bought this really cheap to be willing to spend a lot of money to fix it. FD's aren't cheap to keep up and just throwing parts at it will get expensive really quick. so how much u willing to spend before giving up and selling at a loss? visit the foxed.ca site to download a copy of the fsm so u can diagnose this properly.
u must have bought this really cheap to be willing to spend a lot of money to fix it. FD's aren't cheap to keep up and just throwing parts at it will get expensive really quick. so how much u willing to spend before giving up and selling at a loss? visit the foxed.ca site to download a copy of the fsm so u can diagnose this properly.
Yeah, I bought it for $8500 before shipping from Japan. Really clean car inside and out too. This is my first rotary car, so there’s been a bit of a learning curve.. The parts I bought for it were for what I initially thought was wrong with it. Now that I’m going non-sequential and deleting all of that stuff, I may as well have just flushed that money down the toilet. If the Power FC & non-sequential doesn’t fix it, I’ll probably give up. But even at that point I could possibly make money off of the car, so. Thanks for the recommendation of the FSM.
Installed the Power FC today. I can finally drive the car for the first time since I bought it. Still need to play around with some of the settings, learn the proper values and that sort of stuff, but I can officially apply as much throttle as I’d like. Thanks again everyone for the advice.
10-09-19, 08:25 PM
Probably not the smartest buy you've ever made.
Although, I never put 2 stroke oil in.. regardless, took it up and down the road, still sputters/backfires above 30% throttle. Tried revving it, ignition off then on several times to bypass limp mode, same thing. Even just revving it in my driveway above 30% throttle it sputters/backfires. Although, if I rev it gently it will go up to 5k rpm. But yeah, the problem remains. Stuck in limp mode. 
