DocToxic71

My 2 boys and I have been working on a basket case 93 FD we purchased 9 months ago. Since then we have used this forum extensively to assist in the recreation of the car. I will post pictures soon. 5 months ago we purchased a JDM motor/trans/ECU and proceeded to tear down and rebuild the motor. The rotors generate good compression and turbos spin freely. The rebuild included new silicone vacuum lines, deleting a few solenoids using the simplified sequential diagram, air pump delete, addition of a new AST and other minor upgrades. The car was previously run with a ReAmiya ECU which we reconnected until we can get ahold of a PFC unit. 5 days ago we were finally able to hear the car turn over for the first time and wow did that feel good! After assuring all fluids were filled and new gas in tank we attempted to start the car yesterday without success. The car turns over but will not fire. The problem we are having currently is I'm unsure if the cause is fuel or spark and will begin to start testing for both this weekend.

My question, is there a recommended sequence of checks that catch the most common issues or do most just dive in and validate each system as it comes?

Regardless of the process, both boys have been engaged in the build, and have learned more than I could have hoped. Even better, both now have a deep appreciation and love for the rotary motor.

Thanks for any help available.

cr-rex

iTrader: (114)

It's hard to give a diagnosis with more information. Honestly, when it comes to a stock or reflashed ecu they don't play well with things being deleted. That could be your problem entirely. It's hard to say. Would you mind listing in detail everything you did to the motor? It should be pretty easy to diagnose with more information.

DocToxic71

Thanks for the reply. I'll try to cover what we did. The car was purchased with the block attached to the transmission but that is about all that was connected. All accessories, radiator, starter, pulleys, emissions harness, Map sensor, cruise control unit, A/C system, UIM, LIM rats nest, all exhaust from cat forward and exhaust manifold/turbos were in boxes. We found multiple parts missing in the boxes, so rather than buy the missing parts (1800 + the cost to rebuild the old block) we settled on a JDM motor/transmission which included the majority of missing parts. We started the process of connecting the JDM 16bit ECU to the car but found that significantly more difficult than re-running the old harness to the new motor. We used as many new solenoids as possible and rewired the old harness to the plugs on the "black box". The previous owner included a pack of block off plates along with most of the gaskets for a rebuild. As we pieced the motor back together, we removed the air pump, ACV and tube, and AWS and tube. The rats nest was deleted due to significant corrosion to the tubing and the difficulty of fitting the nest under the new style UIM. We installed the motor to the engine bay and connected the engine bay harness. The fuel was replaced, engine filled with oil and coolant. With clutch depressed, the engine will turn over freely but there appears to be no either no spark or fuel getting to the engine. I plan to start checking for spark first, then tracing back the fuel supply to assure the fuel pump is working and the filter is not plugged. Near as I can tell the trigger for spark and fuel supply come from the main harness, correct?

Thanks again.

TC

Sgtblue

iTrader: (16)

It's been a few years since I fussed with the engine harness, but what "black box" are you referring too? How did you delete the rat's nest and what UIM are you using?
The trigger for spark (timing) comes from the trigger wheel and the crank angle sensors at the front main pulley. The wires are shielded and connect to the main harness (NADM harness pictured)...

DocToxic71

That picture was extremely helpful on multiple occasions for us in the past 3 months. Many thanks for providing it! The black box I'm referring to is the JDM ('96 on?) replacement for the rats nest, the plastic box with 1 less solenoid and internally run vacuum lines. We attempted to run the old rats nest system multiple times but kept running into corrosion and failure to connect with the '96 UIM. The '96 motor is, as expected, much cleaner and has a simplified routing of some vacuum lines. We live in a state that does not require smog checking so I wanted to simplify the system somewhat.

Sgtblue

iTrader: (16)

Appreciate the thanks, but not my picture...just one I saved for reference purposes myself. I don't think I'll be much help. You have a 93 but the later model JDM engine has some differences from what I'm used to seeing. cr-rex and some of the other guys will be way more help.

cr-rex

iTrader: (114)

Cool.... just to clarify, you ARE trying to use the jdm black box? What are the details on your engine harness? Everything you're doing is with the re-a ecu correct?

Absolutely none of the 16bit stuff will work on a usdm fd. I think it was dale Clark that was able to get the black box to work but with your situation of deleting the things you've deleted, I would advise deleting the black box and all the solenoids as well. Keep in mind, stock and reflashed ecus don't play well with things being deleted. Not saying the it's the case here but it's possible that it's not starting for that reason.

definitely do all the standard troubleshooting like you're doing to verify the systems are working as they should. That's important to do regardless. Testing the fuel can be done through the diagnosis box near the fuse box. Use a piece of wire and connect f/p and gnd. It will turn the pump on and from there you can verify everything fuel related.

spark can be checked by putting the spark plug near one of the shock tower bolts and cranking. You'll see the spark jump. Also make sure you're coil packs and plug wires are ordered correctly. Those 3 plugs that go into them can be mixed up very easily. I think it's supposed to be white-blue-black but I'm not 100%. There should be a picture somewhere. Check that your tps is calibrated properly. Check that your crank angle sensors are on the correct ones. White on top, grey on bottom.

we can get you sorted out but doing this troubleshooting with that ecu is likely to lead no where. Unless all the stock components are in place, it's hard to determine what the no start issue is with that ecu. You mentioned you were getting a power fc at some point, after we run through everything we can run through to verify all the systems are working and you still have a no start condition then I would feel comfortable saying it's the ecu along with all the deleted

DocToxic71

Thanks cr-rex, we have been outside working for the past few hours. Positives are that the spark is present at the lead plug on the rear rotor. After checking spark, we sprayed starting fluid in the intake manifold and the car briefly fired!!! Understanding this may be wildly optimistic, the hope is that we are narrowed down to the fuel system. We will try to test the fuel system with that jump at the diagnosis box you described tomorrow. I really appreciate the help.

Understanding the Re-Amiya (Redom) ECU is not the preferred option here and we expect to swap to the PFC unit as soon as we can get one ordered, just trying to keep the kids excited about the project. We have all hit that spot in builds where we loose momentum, at least I assume I'm not the only one who has. It was great to see my son's face when the car fired! All his friends keep telling him to do the LS swap, he doesn't want to and I wouldn't let him if he did. That look of excitement was priceless.

I'll update as soon as we work through the fuel supply. We will move forward with the assumption that the ECU is likely the culprit.

Thank you, I really appreciate the help.

DocToxic71

Okay, here is a bit more info. When jumping the diagnostic port, I can hear the fuel pump kick on at the tank. As I understand, the ECU is controlling the injectors so further problem solving is likely to lead nowhere as long as we are using the re-a ECU. Does that seem reasonable? I will get the PFC ordered today.

The car needs a mid-pipe, the car was previously switched to a 3 inch system and the pipe is cut on the engine side of the cat. Anyone have an opinion and reasons for either 1. keeping the cat and having a custom joint made on the engine side, or 2. going to a straight pipe. Again, we don't need the emissions stuff in Idaho (nice change from previously living in Cali).

Sgtblue

iTrader: (16)

If you have the stock twin turbos, running an aftermarket downpipe, mid-pipe, and aftermarket cat-back can often provide too little back-pressure. This can overwhelm the relatively small wastegate on the twins and lead to an over-boost situation called 'boost CREEP'. And as with any over-boost situation, that can cause the engine to run lean which is 'no bueno' on a rotary. That said, some guys say they've run that way for years without issues. But each car is just a little different and IMO it's a little like playing Russian roulette. Especially when it's a relatively easy (if not necessarily cheap) fix to install a decent stock or hi-flow cat made for a rotary. And other than maybe a bit quicker spool up, I don't think you'll see any huge performance gain with a mid-pipe. Side benefits of running a cat is a car that won't make eyes water within 20 yards with stink. And IMO a better sound regardless of cat-back choice.
And don't confuse CREEP with SPIKE. Spike comes from opening the intake side of the engine and usually presents itself on cool/colder days when the air is dense. It can be controlled by a boost controller. CREEP is a little more insidious IMO, and harder to predict. A boost controller won't do anything for CREEP. Besides running a cat, the only other way to avoid Creep on the stock twins is to port the wastegate, which requires it's removal.
My .02.

DocToxic71

That is what I was looking for. Since we have the cat I'll take it to a shop and have them fabricate a connector to the stock 2" downpipe and the 3" cat/mid pipe. The rear is 3" already.

Incidentally, we primed the fuel lines by jumping the fuel pump and have the car starting and idling now!!! Obviously is quite loud and won't run smooth but at least we are making some progress!

Thanks again to all contributing to this forum as well as those answering specific questions for me. This has been an valuable resource in our project!

Sgtblue

iTrader: (16)

Glad you got it running. Progress!
Well, I have to somewhat correct what I said above. I didn't pickup on the fact that you have a 2" downpipe. Wasn't aware that the JDM stock DP's were smaller.The NADM cars had a pre-cat in the stock downpipe which was a bit of a time bomb. As such we all ditched them and installed an aftermarket DP. Those are all 3" and I assumed that's what you had. I'm not sure, but creep probably wouldn't be as big of a threat with the 2" DP and a midpipe/cat-back. But you would still have the stink and it would be louder. But some inexpensive header wrap and sealant tends to quiet it and helps with heating up the floor of the car.
Just FYI...this is what we had to deal with on the NADM cars when they were new....Stock w/pre-cat and aftermarket for comparison....

DocToxic71

Got it, I think we will try to get the old 3" cat/mid fabricated to fit. If necessary we will replace down the road.
Ordered the PFC today from Banzai and look forward to getting it hooked up.

DocToxic71

PFC arrived today. All the instructions are in Japanese so will work on getting an English translation of the manual. If anyone has the link let me know.
Thanks

Sgtblue

iTrader: (16)

---> http://www.apexi-usa.com/manuals/ele...cs/414h001.pdf

DocToxic71

DocToxic71

Great news! Car is running and driving with the PFC and 3" cat mid pipe. What a day! Thanks again for all the help through the past year as a resource.

DocToxic71

Now that the car is driving, we have noticed the secondary turbo is not effectively spooling. After checking on the forum I've found that we definitely need a boost control and gauge. Any recommendations for controllers/gauge with the understanding that we are running the PFC?

Mr357

iTrader: (14)

As in the secondary turbo is building little to no boost? The first step is to get a gauge hooked up and see what your boost pattern is. A boost controller is a good thing to have, but I don't think it would help you get boost out of a turbo that isn't making any or enough.

Sgtblue

iTrader: (16)

Agree with above, a boost controller only limits the boost level. If it's not spooling it's a different issue....
From the 3rd Gen. FAQ sticky......
For turbo info and trouble-shooting---> Turbocharger Overview

Boost gauge install is pretty straight-forward but FWIW there here are a couple links. At least as often are questions about WHERE to put the gauge and what brand gauges to buy. Personally I bought DEFI 'D' Series gauges back in the day. They're reasonably accurate, weren't expensive and font and back-lightening come really close to stock. 'D' series are discontinued now, but IIRC their SPORT series are pretty much the same. My boost is mounted on a Pettit column mount, so it's right in the line of sight of the tach...where it's most useful IMO. The only other aftermarket gauge is a temp gauge. I could use the PFC Commander, but I'm old and analogue is what I'm used to...and I don't have to read in Centigrade. It's mounted low in a single pod on the 'A' Pillar as described in the first link below.
Boost Gauge Installation
Boost and Water Temp Gauge Install

Crappy pic but FWIW....

DocToxic71

That's what I was looking for. Thanks