cumberlandrx7

Ok so here's my problem, and I appologize if you've heard it before but I didn't have the patience to keep looking. I have a 1990 gxl N/A, last summer I did the TII swap (N370 afm and pressure sensor, and N3A7 ecu which came with the TII engine, N/A harness) I couldn't get it to start with the N3A7 so I made a thread on here, I was told by more than 1 person that I should get a N374 ecu and that would fix everything... I got the N374 and plugged it in and to my surprise it started! but I had an issue with not sending a signal to the injector for the rear rotor. Just to clarify, I had the car running very very smoothly, not lean or anything but it could just idle, once I rev'd up it cut off and bogg'd out and this was with the N374 ecu. I had to wait out the winter and I finally got the car in the garage and bought an N370 ecu and went to plug it in today and... hmmph... nothing. I'm not getting any spark, the ignition coils have voltage, the ecu is not sending any signal to either of the rotors for ignition. This is getting very fustrating because people keep telling me different things and it seems they've been wrong alot so I don't mean to be rude but if you aren't very knowledgeable please don't take a stab at it. I have been waiting 2 years to get this thing going and I aint missing out on this summer.

Brodie121

iTrader: (8)

N374 will most likely not run the rear rotor with a usdm harness as n374 is a jdm ecu. This is a common issue. N370 is what you want, is the one you got out of a running car?

cumberlandrx7

I bought it online and was told it was from a running car. I did open it up to see if anything had been noticeably damanged but the only thing that caught my eye was a black chip ontop of another chip with a sticker that reads "FC3STR.VU5" but it just stands out as none of the other components have stickers, could be nothing dunno.

Brodie121

iTrader: (8)

ok is the bottom thing you think is a chip possibly a socket for a chip? Because it sounds like you have a chipped ecu. Now i dont know why it wont run, it could possibly have been setup on a bridged motor, which iirc has a different timing setup. anyway, could you possibly snap a picture of the inside?

Brodie121

iTrader: (8)

And is it an n370 for sure? as FC3S is a japanese designation, "FC3STR.VU5"

cumberlandrx7

As far as I can tell it is an N370 ecu. I did start to think the second I unpackaged it that something felt loose and maybe the covers/lids w/e were changed. Again like I said I bought it online so I can only take the sellers word on this for now. I was only able to take a few photo's with my phone but here they are.

http://img687.imageshack.us/img687/3479/imag0049g.jpg

http://img232.imageshack.us/img232/6291/imag0052h.jpg

http://img26.imageshack.us/img26/6041/imag0050cy.jpg

http://img35.imageshack.us/img35/61/imag0051id.jpg

Hope this stuff helps. Thanks

cumberlandrx7

bump. hate to do this but I could really use this message boards help. Thanks in advance.

cumberlandrx7

Anyone have any feedback to help me at all?? I've already tested this by hooking a wire with an led on it to the positive side of the battery and to each of the 4 injector pins right from the ecu. When the car is off the led is on (ground is established) and when I turn the key it is supposed to turn off but it's still on. With my N374 ecu however this works properly, the light turns off and when the key is turned and the car is started the ecu grounds and the injectors get current so the light flickers on/off/on/off etc. This tells me its not an improper ground so is there anything else I can try or is this a for sure faulty ecu? I don't have the funds/time to keep throwing money into ecu's I already have 4 and I don't plan on collecting them. Please help someone!!!

jackhild59

iTrader: (7)

Here is where you are:

You have a N374 and it is a known issue that the 374 will work with an orginal TII, but NOT with a N/A to turbo conversion.

You have a POSSIBLE N370 that does not work at all. You are trusting someone who told you that it is a 370 and BTW it was rattling when you unboxed it.

Now you are demanding help and getting pissey? No one can help you on this board. You have TWO nonworking ECU's and you indicate that you have a total of 4 ecu's that don't work. The solution is in your hands.

Question: Does the stock N/A ECU make the car run? Does it drive (don't go into boost!) It should. If it doesn't, you have a harness problem. If it does, you have another bad ECU.

Good Luck!

cumberlandrx7

I appologize if I am getting pissey but you have to put yourself in my shoes, "IF" i want to return this ecu to get my money back I need to know for sure it is the problem, as each day passes I am getting closer to losing the oppourtunity and being out of $. Also, the further down this forum list it goes the chance is nobody will even look at it... so I appologize but I need the help and am pretty desperate to get this car running.

The seller of the N370 is from a garage and I contacted him and he garauntees it was pulled from a car that was started and and idled fine and was parted out. He also offered me his number to see if he could help but he wasn't very knowledgable about the car. The 4 ecu's I have btw are an N3A7 (came with the engine and doesn't work, obviously) the N374 which I know wont work, the stock N350 from the N/A engine and then the N370 I just bought.

I haven't tried the N/A ecu no, but I can tonight. I just assumed that since the N374 starts the car up and idles fine that the harness wasn't the issue but that was a bad judgement call on my behalf. If the N350 doesn't work however then I guess I have alot of wiring to trace, I just find it strange the N374 starts the car still if the harness is the issue. Thanks for the reply and I'll give this a try.

Brodie121

iTrader: (8)

An N3A7 ECU is from an FD. And your saying it came with your motor? Now excuse me if this is dumb question, but do you have a 13brew?

HAILERS

Bingo!

cumberlandrx7

Nope it's not a 13B-REW because A. The engine mounts were stock and fit perfectly B.The engine ha top mount intercooler C. Single turbo D.Everything fit on the engine is 100% installed and everything went smoothly, I had tons of photos for wiring and tagged everything so once i get the ecu in its ready so everything in the drivetrain fit perfectly.

HAILERS

Why did they sell you a sixth generation ECU? For a series five car/engine?

Brodie121

iTrader: (8)

If it ran partially on the N374 there isnt really a reason it wouldnt run on an N370 unless the ECU has something wrong with it, was the car the N370 came out of stock?

+1 to trying with your n/a ecu

cumberlandrx7

mmk guess I gotta try that then, I won't be able to until tommorrow but thx for the help guys oh and HAILERS i have no clue and I wondered the same thing once I got home the problem is I bought it straight cash under the table from a japanese motor import company

g14novak

iTrader: (1)

I was wondering the same thing. The computer is chipped so it could have been modified.


You have a chipped N370 sitting there. Why don't you download a rom tuner, get a rom tuner box and reset the chip? 240 guys do it all the time.

And what do you mean you bought it straight cash under the table? You mean they jipped you on no warranty since you don't have papers? That sucks.

You said you have 4 ecus? n/a, jdm t2, usdm t2, and fd, right? Just hook up the n/a and dont boost it until you can get a good ecu or safc. but more than likely good ecu.

cumberlandrx7

Ok I finally got a chance to get in the garage. I made a mistake btw the N/A ecu is an N351, though I don't think it makes a difference. I tried to start the car and it wouldn't go, I didn't spend much time trying to figure out what it was because I think I remember trying this ecu when i first swapped the engine in and found something weird with the fuel pump not working properly (I could be wrong on this my memory is weak). I did notice however the engine check light was on, now I don't remember if it was on for the N370 or not but neither the N3A7 nor the N374 showed any errors. Is this sounding like it could be one of a large list of possible problems??

jackhild59

iTrader: (7)

Now I am thinking...Why would a Japanese Import Motor company have a chipped N370 ECU laying around? And why would someone at that company sell it to you for "cash under the table"?

So let me frame that thought into a statement.

You bought a shady ECU from a thieving, dishonest employee of a company that has no business reason to even have the ECU they allegedly sold you.

Maybe you got f----d, because if he will steal from his shop, he will darn sure steal from you. You know that Karma hates a thief?

You should post this problem in the TECH SECTION FOR NON-WORKING STOLEN PARTS section of the board!

HAILERS

Somehow I think the pinouts for a FD are somewhat different than for a series five. Might check b/t the two FSMs to figure that out.

I know nothing about FD's and I'm surprised that the series five EM harness would fit on the FD ECU. I guess it does though.

Seems to me the FD ECU has twelve more pins than the series five ECU. Seems we'd uh noticed the lack of compatibility of the harness to the ECU. Got me.

cumberlandrx7

Ok let me clarify a few things so that we can stay on path with debugging this not making false assumptions.

I didn't buy the ecu from the japanese motor import company, I bought it online and the seller has agreed to exchange it because he works in a garage and parts rx7's.
If the ecu is chipped I can just echange it for a new one but he said this one was in the car and they had it idling.

As far as my statement regarding my under the table buy. I bought the engine from a japanese motor import company.
This was at the beginning of last summer, they are a good company with good reputation. I, yes I, brought cash along and I was the one who asked him if he would take $350 less if I, out of my own choosing, yes ME, paid in cash. He was reluctant and I was tight on cash but he agreed.
That being said, he gave me their number and said call if I have questions about the swap or anything else, this did however leave me without a proof of purchase of any kind.
At the time I didn't mind because like I said, tight on cash lol.
The ecu that came with the engine was wrapped and packaged seperately along with some other spare parts they had no use for.
Even after unpackaging it I was unaware it was the wrong ecu, I never checked the pin-out and I had no reason to plug it in yet, so I swapped the engine in and with the FD ecu, there are 4 connector slots, the 3 from the harness plug in directly but one is left missing.
I knew right away I couldn't use this ecu but it was already pretty late in the summer and with no proof of purchase how would I exchange the ecu from the company i got the engine from.
That's why I started a thread on what ecu I need, I was told to get the N374 over the N370.

So that leads us to where we are now.

Anyways, back to debugging. I'll see if I can pull the error codes and get it started with the N351.
Should both the N350 and N351 start the engine??

HAILERS

Either should Start the engine.

cumberlandrx7

hmm ok so I pulled the error codes, now I have the N351 ecu in but would some of these error codes show up although they aren't errors? just confusions with the ecu???

Anyways, with the N351 ecu I got 3 codes:

Code 30 - Solenoid, Split Air Valve
Code 38 - Solenoid, Accelerated Warm-up System (AWS)
Code 41 - Solenoid, Variable Dynamic Effect Intake (VDI)

the split air valve, I did the test for it as described below and the output was 11.98v
I unplugged it and tested from the plug attached to the harness and it doesn't change to 2.5 either.

Anyone know the cause of this? or should I replace the valve with the one from my N/A engine?

For code 38, I don't see the AWS on my engine, nor on my old N/A and there is no connector near where they specify, I assume then the AWS has been removed??
I can include pictures if necessary but if I am not mistake it is located beside the BAC right??

For code 41, I am at a complete loss. I cannot find anything not even in the FSM (which btw does not recognize 41 as an error code) about how to test this or what could be the cause.



Here is the test I followed (from the FSM)

cumberlandrx7

Oh and the N370 ecu does not even light up the engine check light.

Is there something I can unplug that will 100% always throw a code??

no_luck

iTrader: (3)

tps sensor easy to get to and will throw a code