I tried putting an NA tune '95 JWT ECU in my 4.5 gen today, and at first it idled fine. After driving for a few minutes, however, it would no longer hold idle. The RPM needle would just drop straight to 0, and the car would stall. There was no hesitation--it would just straight stall if I didn't give it gas. When I plugged the OEM ECU back in the car idled fine. Does anyone know what the problem may be? Perhaps it is an AF problem? The car drives fine w/ the JWT aside from the idle issue. Thanks in advance for your help.

 

Perhaps Jim f'ed up your particular ecu during your 6 year waiting period. Did you try pulling the codes? Maybe it was a hickup, but double check your iacv for the hell of it. I would hook the jwt back up and try to get under the engine bay to see if its opening.

 

What TB are you using?

 

I'm using a 4th gen TB. I just tried the ECU in my VQ30DE 4th gen, and I had the same problems--it seems like it is a problem with the ECU. I bought this ECU second hand on the .org, so I'm going to have to talk to the guy to see what's up. This ECU was supposed to be in good working condition. We'll see how far I can get. Thanks for you help guys.

-Tim

 

I had the ecu for about 1 month and it worked great no idle issues ever. I did sell it to you in "good working condition".

 

Babymac:

I didn't call you out in this thread, because I was still diagnosing the ECU problems. I just said that I would have to "talk to the seller to see what is up." I apologize if I offended you, but that was certainly not my intention.

So, I messed with the IACV screw and was able to keep it from cutting out. It still hesitates a little bit, but I will work with it some more. Thanks for the help guys. Time to go have some fun @ 7000 rpms.

-Tim

 

I was not offended and really hope you can work this out. Good luck and 7200 rpm is really fun!