Rx7_Nut13B

iTrader: (1)

OK i have a problem that i just cant find the problem.

Specs. 93 A/t ECU N3A2 18 881B

When i first got the car it had been sitting for some time and hadnt run. So when i got it home i changed all the fluids and put some oil into the motor, before i tryed to move the motor. So after i let it sit, i turned the motor over by hand and put some more oil in it. Well long story short, it started and ran pretty good for sitting 6+months.

So i changed the belts and after that i am getting a Check Engine light,and it will not start right, nor will it run right. Kidda have to play with the gas to keep it running if you can get it to start in the frist place.

So the check engine light shows a #2 Code ( No NE Signal ) witch is the Crank Angle sensor, Ok i check the sensor itself like the manual says to, it was Fine. So i called a friend that works at Maz-Max ( A local Rotary Friendly Place ) and he said it is most of the time the Wiring harness, so i check the connections and sure enuff the wire was broken at the connector. So i order some used ones from a member of the fourm and soilderd them on there and srink raped them. Ok i thought i had the problem solved. Well it is still giving me the same check engine code and still not starting. Yes i did clear the codes. Disconnect the Neg and wait 20 sec and hit the brake. The only thing that i can think is that the wires touched the engine block and hurt the ECU, Someone told me that they are AC instead of DC, is this true.

Then thing that is getting me is that i still have spark and it spells like i am getting fuel. Cause it will try to start untill it floods out. Then it is allmost impossible to get it to try and pop off or make any nosie that sounds like it is trying.

I am desprit to find the problem, i am thinking about running new wires all the way from the Crank angle sensor to the ecu. But have to find out with pins they are.

Maybe i can check the ohm's at the ECU harness to see if there is not a short in the wiring.


I AM WIDE OPEN TO ANYONES HELP

Please if you want give me a Call (979)233-1702 I will be Up really Late i am in Central time Zone (Texas)

Also one more thing The Hold light is flashing and didnt no if that had to do anything with the problem.

Thanks

Rx7_Nut13B

iTrader: (1)

Ok sense i posted this , i have been doing some checking and did everthing in the manual.

I have checked to see if the wires are shorted to ground and they are not, then i check the ohm's at the harness where they go into the ECU and they are in the Normal range, So now it is saying Change the ECU.

Does anyone have a ECU for a 3rd gen Auto

Or is there something eles i can try.

Gadd

So you've checked for continuity between the connector and the ecu? I havent seen an ecu fry becouse a sensor wire was grounded. But it may be possable. I can't remember what the connectors look like, but is it possable you switch them? I'd double check your connections.

Sgtblue

iTrader: (16)

If you end up wanting to change out the ECU, just post a WTB in the 3rd gen. parts section. I've seen them in there and Ebay periodically. Might be someone out there that has done the manual swap would let it go cheap.

Rx7_Nut13B

iTrader: (1)

Yea i have checked the Ohm between the connectors and everthing is fine, if you go with what the manual says it should be.

Yea i am going to eather find a 5sp or Auto ECU. Eather will work just with the 5sp i will loose my Hold button. Am i Correct on this point.

Mahjik

iTrader: (1)

IIRC, the plugs are different for the ECU between Auto & Manual (which is why the manual swap can be a pain because of the wiring).

BoostFrenzy

Some what unrelated but when I removed my ECU to fix the blower I noticed coming off one of the larger harness connector is a single pin female black connector that doesn't appear to go to anything (no, not a grounding strap that goes on the bolts)... i think the wire was black with yellow stripe?

weird eh

Rx7_Nut13B

iTrader: (1)

Bump..

Just wondering if anyone has anymore ideas before i change the ecu

***LOOKING FOR A ECU ALSO***

Rx7_Nut13B

iTrader: (1)

Update!!

Of i talked to Chris @ Rotary Proformance and told me that the 5sp and Auto ECU connectors are the same, that is how they can use the Power Fc in a Auto.

Also i ask about if they had a ECU to sell, they didnt have a N3A2 , but had a N3A3, and N3A4. Does Anyone no what these two go into.

Also he told me that i am on the correct path after i told him that i am getting a #2 Code with is the NE Signal and should not have spark, BUT i still have Spark!!

Also i got the Hold light blinking and this ECU is the New one that is suppost to stop the Blinking light.

I am getting Closer to the Solution....YES

BigAl65

So, did it appear to run fine before you changed the belts? I sounds like you may have unhooked an electrical connector while working on it. Check the connections at the air pump and other areas close to the belts.
As for the hold light, cross the tat and gnd (or the ten and grd, I forget) and the hold light will give you the code for the transmission computer.
Allen

Rx7_Nut13B

iTrader: (1)

Yea it started and ran Great.

Then after that i start it and all this stuff started to happen. There was a Broke wire on the Cranck Sensor.

Mahjik

iTrader: (1)

Looking into the archives, the connections are the same. You'll have to jumper the neutral safety switch and that should be it.


https://www.rx7club.com/3rd-gen-archives-73/flashing-hold-light-23584/

Rx7_Nut13B

iTrader: (1)

OK check this out.

I found out that a

N3A1 is a Fed. 5 speed
N3A2 is a Fed Auto
N3A3 is a Cal 5 Speed
N3A4 is a Cal Auto

So can i use a Cal Auto computer in my Fed Auto

It will proably give me a Check enigne light for someother thing that are not on the fed. I no one would be the sensor that is on the egr Valve

BigAl65

I notice you said you disconnected the negative on the battery and waited 20 seconds and hit the brake to clear the codes........If I'm not mistaken, you should disconnect the negative and HOLD the brake pedal down for at least 20 seconds to clear the codes......
it may sound silly but its worth a try.......

Did you check the auto ecu codes?

Rx7_Nut13B

iTrader: (1)

How do you check the Tran Codes

BigAl65

Read my post about 4 before this one.......the hold light will flash the problems....

bfeito

Hey Man,

I have a 94 5 spd. ECU sitting in the garage, with the harness as well. If you want it, shoot me a PM and we will work something out.

Brent

Rx7_Nut13B

iTrader: (1)

Ok now things are really getting wieird,


I have had my ECU out of the car for a day now i put it back into the car and the check engine light is out and the hold light is not blinking any more, but now it is trying to start so i checked the spark and there is no spark on the Front Trailing, so i check the power going to the coil pack and there is none. How do you check the ingitor with out mazda's checker.

Is there a diagram to build your own.

All ready searched the fourm and a few says to check the igintior but how do you do this.


I am Really Really Sorry for all the Questions but this is the only way to learn. Well that and Reading, witch i love to do also.

THANKS TO EVERONE SO FAR THAT IS TRYING TO HELP!!