anthony86

the primarys work good the secondary turn on, at 3800 like they should but one clicks spontaniously

anthony86

Yes the front secondary works perfect the rear secondary clicks for a minute then quits for a bit and then starts again

anthony86

Ive been trying to find out what would make it click for a while then quit clicking. Then fix the problem. Because I have no clue what would make that one injector not work right. The only thing I can this is the ecu is no good? Then car runs great and accelerates great, the boost is working great till the secondarys turn on then it starves for gas. Do you have any ideas that would make that injector not work right?

fcrotory

iTrader: (20)

Could just be a bad injector. Try getting them tested and cleaned.

So, your car starts fine and will even idle untill its warm? But if you stab the throttle or rev it it will come back down too far?? Sounds like your throttle plates might need adjustment. Its kinda a pain to get right again once it gets messed with. Just make sure after you adjust throttle plates you check tps and make sure its still at 1k-ohm at closed. Well as close to 1k-ohm as you can get.

satch

iTrader: (1)

The signal wire from the ECU if accidentally grounds out it would fire the injector. If one of the wires in the injector plug are pulled back then the injector would not operate properly. If the signal wire at the ECU were pulled back then it would also affect operation. You can unplug the TPS and disconnect the vacuum hose to the Boost Sensor to create load on the engine. In doing so, you can rev the engine above 3800 rpm while in neutral and the secondary injectors will fire. And rev the car in neutral w/no modifications done and see if the engine bogs. Then place the engine under load and compare the two.

fcrotory

iTrader: (20)

You wont have a motor if you dont put at least a t2 fuel pump in it.

anthony86

Alright im gonna go get a new fuel pump and put it in really quick. Sure it will run better, but that wont make that one secondary injector work good. Do you know what would make that one secondary injector not click right?

jimmydanny

Mine did before, but I can't remember exactly what was wrong... I have to think, might get back to you,, might not.

ANd for the record, N318 ECU's do exist, they are JDM/EU ECU's, US is N332 (both manual).

EDIT: Btw, if you got cash to fix your engine, you can probably spend 100-200 bucks on a new ECU on ebay or on the forums here, and try that and see what happens.

But I would check the two grounds on the top of the engine (one in the solenoid rack/IC support, one on the engine).

anthony86

Thanks let me know if you remeber what it was. I changed the injectors last week thinking that one was no good and after i did it, the same injector still didnt operate correct. All the wires going from ecu to the injector look ok look fine. Im thinking that something is wrong with the ecu. I put a new fuel pump just now luckily it was in stock but it really didnt make any difference. Im gonna go check the ground and see how they look... the engine sat for a long time so it has alot of oxidization and rust on it.

anthony86

So I checked all the ground for the most part they look good, however I noticed the ground that runs in the distributor wire is broken could that affect anything? And I couldnt find a ground on the solenoid rack, but the others are pretty clean

anthony86

Do you guys think I should get a new ecu? maybe thats why that one injector isnt working properly?

anthony86

let me know if you guys think this is a bad idea... Hook a jumper wire at the ecu from the good working secondary injector to the bad secondary injector, then see how the car runs at 4000 rpm.

anthony86

So I hooked a jumper wire from the good secondary injector to the bad one and i ran great no cut out but still probably not as good as it should. Does anybody know what would make that rear secondary not click right???

Akagis_white_comet

iTrader: (4)

Bookmark this, you will refer to it often:
Rotary Resurrection home of the budget rebuild.

This is starting to get out of hand, so I'm going to step in and make a few corrections to prevent misinformation.

1. N318 is the ECU for all J-spec S4 cars with Manual Transmissions. N319 is the Automatic version. For simplicity, let's refer to them as the N31x ECUs. European-spec S4 cars were only N/A and received the N322 ECU, while North American S4 NA cars received the N326 (manual & early automatic) or N327 ECU. The difference is that Euro-Spec cars have a distributor while everywhere else uses a CAS. For easy reference, let's call these N32x. North American S4T2 cars received the N332 & N333 ECUs. Functionally, they are identical, so we can call them N33x. S4 Verts in North America received the N338 ECU. I've read that it can be used in place of a N332/N333, but cannot confirm it in my own experience. Do a search and you will learn more about it. Euro-spec S4T2s got the N344 ECU. For the most part, the part number prefix indicates development order.
How I know this: I have all 3 regions' parts catalogs

2. In the picture, I see a S5 Radiator (pressure cap on top of radiator, S4's is on thermostat housing). It probably isn't of much concern, but I believe there is no Coolant Thermoswitch in the bottom of it like there is with the S4. If memory serves, I believe the coolant thermoswitch was for the Cold Start System, rendered inoperable by a TSB from Mazda shortly after the FC's introduction. If I am incorrect about this, feel free to respond with the correct information.

Your cooling system needs minor but immediate attention as it can suck in air through the open hose barb underneath the S4 pressure cap. This barb is for the overflow bottle's hose, which you have on the S5 radiator instead. Move the hose to the S4 location and put a vacuum cap over the S5 barb, preferably with a zip-tie for extra security.
How I know this: Spent plenty of time in the parts catalogs and trying to find a suitable radiator for my 20B S4 on the cheap.

3. The intercooler is a J-spec one, making me wonder if your engine isn't a J-spec one as well. All North American TII intercoolers say "Turbo II", while the J-spec ones read "Rotary Turbo". Again, no functional difference between the two but it does beg the question of what you actually have...

4. Combining items #2 & 4, my gut feeling says you have a J-spec S4T2 engine. The only way that I know of to pin this down is to check for EGR passages in the rotor housings near the exhaust ports. The bonus to this is you'll have to remove the turbocharger and be able to positively identify it by the flange. S5 is a very square/rectangular flange while the S4 one is shaped more like a trapezoid.
S4:
S5:

5. Do a continuity test between the injectors and ECU connectors. (check the Wiring Diagram for the correct pins). Anything more than 0.10 ohms means someone has hacked into it and did a shitty job. 0.07 ohms is flawless, but a a little leeway to account for age is okay. Anything more than 0.10 ohms needs repaired.

6. I don't think your ECU is junk as FCrotary implied. Granted, butchered wiring can fry one and they do have some soldering issues that crop up (cold solder joints/leaking capacitors, all well-documented items). I have not personally seen a fried or damaged ECU beside a known good one so I cannot say with certainty one way or the other. Aaron Cake is better equipped to answer this kind of question than I am.

7. There is no logical reason to replace the fuel pump with a TII one, unless yours is dead. If your pump is questionable, test it via power & ground straight from the battery. You will hear it run if it is good. If it is bad, just go straight to a FD pump as both Aaron Cake and myself did. Clokkar is correct about Fuel Pressure. Satch is correct about Fuel Injector Impedance and the Resistor Box.

Also, remove the jumper wire you put in between the Secondary Injectors' signal wires immediately. There is good reason why our ECUs have individual outputs for each injector. Piggybacking them as you did could lead to detonation and rebuilding your engine. The rear rotor is 180 degrees out of phase with the front rotor. When one apex seal points up on the rear rotor, an apex seal points down on the front rotor. When you fire both injectors at the same time, you are ignoring this difference and injecting fuel in one rotor before it is ready for it. This amount then explodes early, which is called pre-ignition or detonation. If you had done this on the primaries, it would happen very quickly. In addition, you are making the injector output on the ECU pump twice as much current as it should. This makes things melt inside it...

8. If my hunch is correct and this is indeed a J-spec engine, the harness would have to have been modified/extended to be routed correctly on a LHD car. In the picture, I see a few spots with bare wires visible. This would indicate that someone had been in there, which is why I am going to strongly recommend doing a continuity test on EVERY SINGLE WIRE IN THE EMISSION HARNESS. The main one that affects everything is the ECU Ground, illustrated here:
Proper RX-7 Grounding Procedures

9. Every FC's stock ECU requires an Airflow Meter to operate. Considering the highly questionable state of the wiring, engine and associated parts, my personal recommendation is to do a compression test (determine overall health of engine). Once you have those numbers, you'll be able to go the next step. If your engine is getting tired, get it rebuilt by a GOOD shop such as Banzai Racing Banzai Racing Home Page. Once you have a known healthy engine, then turn your attention to wiring. Considering how the present harness is, most likely a hacked-up J-spec one with North American additions, going to a standalone would make a lot of sense. C. Ludwig does excellent work in building harnesses, or you can build it yourself. Either way, once you have a standalone, the Airflow Meter can be removed entirely. You may wish to look at my build to see how to approach building a harness correctly: https://www.rx7club.com/build-thread...888195/page13/

clokker

iTrader: (2)

Wow, that was quite well done.

anthony86

The engine is under 60,000 miles. I compression tested it when I recieved it and it has about 80 lbs compression. the radiator cap is plugged off so it wont leak. The engine came from japan. anyways the wiring harness is in decent shape except for were it was cut, but I have it back to normal and seeled off. The harness was alittle tight going into the car, but ive been planning on getting an adapter or something to fix it. I tested all the elctronics on the engine step by step with the manual and they are all working like they should. I apreciate the help and advice thanks. But Im still wondering why the rear secondary injector doesnt work like it should. I checked all the ground, I tried adding one to the ecu and engine but it had no difference.

anthony86

Thanks for the ground chart im sure a few of them are dirty the engine sat for a very long time... I didnt know were most of them were im gonna clean all of them tomorrow and hopefully It makes a difference. Im pretty sure they were never cleaned. Thanks

satch

iTrader: (1)

Some of the causes for the injector to not work properly are wire related as already stated. So perhaps you might want to check this out. The rear secondary injector has a Light Green/Red wire at pin 3F. Now you can see if this wire is properly placed within the ECU plug or not. You can w/the plug pulled from the ECU take a voltage reading on the LG/R wire w/key to on and see if you get 12 volts or not. If it does not read 12 volts then the injector plug is not secured to the injector or the wire in question is pulled back in the injector plug and thus not making proper contact.

And backfiring w/the accelerator released is commonly caused by the TPS.

jimmydanny

Well, it is not entirely correct either. I have seen several S4 TII in Europe that are not imported, and not swapped. And Japanese S4 TII ECU's (some) were labeled N340, why is that?

First you say that European spec S4 were only N/A, then you say that Euro-spec S4T2 got N344.

I think you made some of us more confused, I will stick to my S5, I need a N374, much easier to relate to :P

anthony86

Thanks tomorrow morning im gonna clean all the grounds make sure the injector has a good clean conection... should have did that when I changed the injectors owell. Im pretty sure the wire is in the right spot, the computer came with the engine. ill double check you never know, it could be wrong. Do you have any other advice for stuff I should check for while I have the manifold off???

anthony86

I accidently broke a prong off the intake air temp sensor. Is that important or is it something i can go buy some other time?

fcrotory

iTrader: (20)

I never said his ecu is garbage. I told him his harness is garbage...because it is!! Obviously this guy is very inexperienced with rotarys and needs to explain his problems more clearly. Hacked harness and electronic issues...Hmmm wonder what it could be?? Using a s5 afm on a s4 harness is all bad. Boosting with a na fuel pump?!?! BAD!! I told him he didnt need a t2 pump to run it at idle or free rev. But NOT to boost. The OP needs to read more about these swaps and what not to do.

anthony86

Im pretty good with rotarys... just not electrical stuff, kinda ok with turbo stuff. Getting better...

anthony86

My fuel pump was old anyway and didnt hurt to change it... im just looking for advice to get my car running better. Not trying to argue with people about it, just want my car to run right. I know that harness is crap but I dont want to do all the work at the moment to change it, or I already would have changed it.Im open to any good advice to fix it.

fcrotory

iTrader: (20)

Well considering the lack of info you supplied. Not that good lol. But ive been down the same road. My knowledge of rotarys is small compared to some of the guys on the club. BUT, ive done these swaps and been thru most of your problems. Ive blown a motor due to lack of knowledge. But you learn from your mistakes. As you can see you didnt get much help from the thousands of people on here. Thats why im throwing in my 2 cents. Because i needed LOTS of help when i first started and help was scarce lol.