Idle RPM haywire after engine and tranny swap
06-21-2011, 06:23 PM
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Idle RPM haywire after engine and tranny swap
Hi all, I have been searching for any related problem on this thread but cant find it. My EG5 old 1.5L carb engine blown off, and now I just had the engine swapped with JDM D15B auto and I used back the manual tranny from old engine and the ECU is P2J. The problem is when the engine is crank cold the idle RPM will stay high at about 1500 and stay high all the time thru. What I did now after crank cold start I will let the engine warm up for say about 5 minutes, shut off the engine and start again. The idle RPM will drop now to about 500 to 600 which I think it should be that way, but the problem is when the car is stopped at like junction or traffic light the RPM will drop further and the engine will die. I dont know what to do....please help
06-21-2011, 08:49 PM
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Re: RPM haywire after engine and tranny swap
I have checked all the vacuum lines are on, forgot to mention I am still using the auto ECU. Does it got anything to do with it??
06-22-2011, 01:24 AM
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Re: RPM haywire after engine and tranny swap
Thanks bro, anyway I still cant figure out why high idle RPM at cold crank and it ll drop when engine is killed and restart again.
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06-22-2011, 09:14 AM
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Re: RPM haywire after engine and tranny swap
My opinion, I would think the auto ecu controlling a manual trans is the problem. Not sure how or why, but i would assume the ecu is not receiving the info it is looking for. Hopefully someone with knowledge of this will chime in here.
06-22-2011, 05:26 PM
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Re: RPM haywire after engine and tranny swap
I don't think you have a choice BUT to change out the ECU. It is the wrong one for your application. I'm doubtful the IACV is the issue.
06-22-2011, 06:54 PM
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Re: RPM haywire after engine and tranny swap
Yea, I strongly feel the ECU is causing the problem, becoz after the auto tranny from that JDM D15B swap with manual, there were few unused sockets left out. Now if I am gonna put in manual ECU, how about the engine harness, should it be replaced too?
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