Plug in new Mugen ECU, engine cranks but car won't start. Plugs back factory ECU and car starts right away. What's wrong?

This is on an '01 ITR with Mugen '00/'01 ECU jumper harness.

 

not to sound stupid, but all the plugs "snapped" in right? when I got my jumper 1 pin was a bit off. I bent it very slightly and then everything clicked in place. Bad jumper? do you have a buddy with a 97 R? plug it in a vehicle without the jumper.

 

all plugs checked and checked. same result.

unfortunately i don't know anyone with a 97 or 98 R...

 

??? Not sure, did you try talking to the people where you got the jumper?

 

call king motorsports... maybe they coulld help you out.. there pritty good over there.

 

not sure if it could be related or not, and I dont know too much about Mugen ECUs or how they are built, but I ended up frying my AEM ECU somehow, and I believe it was from plugged it in and unplugging it from the harness frequently. Was your battery connected when you tried to plug in the ECU? I had to send the ECU back and they rechipped it and it worked fine. Maybe you shorted out the ECU somehow? I would definitely try to find another R to plug it into. good luck

 

How much is the mugen ecu and what exactly does it do? Can someone fill me in?

 

You have the 00-01 model ? You have to GND the immobilizer and the car will fire up right away. IM me if you cannot figure out how to do it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AJ PwR &raquo;</TD></TR><TR><TD CLASS="quote">You have the 00-01 model ? You have to GND the immobilizer and the car will fire up right away. IM me if you cannot figure out how to do it. </TD></TR></TABLE>

I got the ECU and jumper and did not need to ground anything and it fired up right away. Car during idle ran like *** with the A/C on.

 

that ECU sure worked well in 234 Dan!

yshi - who has no $flow & can't buy it off dan

 

NO need to ground my immobilizer unit either. Immobilizer unit is bypassed with the Mugen ECU. Car ran well but didn't feel any improvement except for a deeper exhaust tone due to different mapping of fuel/air mixture. This is with Mugen header (2.5') and twinloop. Maybe a Mugen intake will make this package complete and work the ECU to what it's design for.

 

Isnt the Mugen program for their N1 motors?

Your gonna need to get some cams gears and fpr to tune the ecu to your setup maybe even a VAFC...

As far as I remember the Mugen program runs super rich...not exactly the best for throttle response and peak power

Hit the dyno and base line your stock ecu with your Mugen and see what the A/F looks like.....Mugen = 11.9:1 lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yoshi234 &raquo;</TD></TR><TR><TD CLASS="quote">that ECU sure worked well in 234 Dan!

yshi - who has no $flow & can't buy it off dan </TD></TR></TABLE>

I agree... you know you need the ECU....I'll hang on to it for ya...

 

I just noticed two of the wires are cut on my jumper harness. Can someone check and verify if that's normal?

 

Hey Nimbus, that doesn't look right what you have compared to mine. my jumper does not use the first three slots (looking at it from left to right). it only has the Red/Green wire on the forth slot. there are NO wires in those slots. When I unplug it you can see through it.

 

Those cut wires are for the secondary O2 sensor.

Who did you get the harness from?

Also, there is NO need to ground the immobilizer. The Mugen ECU doesn not have an immobilizer as mentioned in a earlier post.

What I think may be suspect is the harness. I am guessing that A16 ('99-'00 Civic) is wired up for the fuel pump relay wire and not A15 ('00-'01 Integra). I may be wrong.

If you have any more details please email me so I can help you solve your problem. I don't get a chance to check honda-tech that often any more so email will be your best bet.

-kenji

 

Can someone check their harness for connector A (bigger grey plug), row 2 (wire side of female connector). From left to right, first wire color should be black/blue (A12) as seen in pic.

I need to know if the next wire color (right of blk/blu) is orange, then blue/white, then red/yellow, then green/yellow.

Thanks!

 

Nimbus,

Judging by the pictures you have posted that is not one of my harnesses.

The orange wire that is left at A13 is for the 3-wire IACV for a '96-'00 Civic SOHC motor (non-EX). I have never left that wire in place for a OBD2v2 to OBD2v1 harness. Apparently, the plugs that were used to make that harness came from a '96-'98 Civic engine harness, which is fine. However, I do not feel it is acceptable to leave wires in place that would serve no purpose.*

*Your application (00-'01 ITR to Mugen N1 ECU) would not warrant the use of that particular wire nor some of the other wires I have seen included in the other picture. I am not bashing the quality of the harness I am just stating the facts.

In addition to this, the pictures of the D plug show wires that are cut (not removed) for the secondary O2 sensor. I would not let a harness ship with that sort of workmanship. The wire/pin(s) should be removed completely.

I am still more than happy to help you in any way I can to get your car running for your race on Wednesday.

If you can't get another harness in time I will call you and walk you through the trouble shooting procedure. Email me if you have any questions.

-kenji

 

Nimbus,

I looked at my wiring and it looks nothing like yours. The wires are not event the same color. reading left to right. BLK/BLU, 2 slots empty, Red, Grn, Blk/Red.....hope this helps.

 

Dan, you have the right harness. Kenji and I have determined mine is wacked...

Looking at the bright side, atleast I know the problem is my harness now instead of my ECU.

 

Got the right harness. Everything working fine now. Thank you.