electrical problem unsolved

garden1 · Post by **garden1** » Sat Feb 26, 2011 3:53 pm

SO i just got my 1st gen 4g63 in a mighty max. This was my first time i have ever done this swap. It was fairly easy because i am a student at an automotive program at a college, so i had some good resources like michell on demand and all data. One of these days ill upload their wiring diagrams, wich in my opinion are better than any other diagram i have seen. My swap started the first time i turned the key over. Very exiting, but only one problem that i cannot figure out. During open loop the engine runs fine, but once i am in closed loop(once the engine warms up) the engine starts to idle high and it misfires. I narrowed it down to the closed throttle switch. once i unplug it the engine stops misfiring but there is still a high idle. I unscrewed the closed throttle switch, and whenever i touched the tip of it to any part of the intake manifold or throttle body it starts to do the misfiring. anyone have any ideas. I have gone through all my wiring twice and haven't figured it out.

jeffball610 · Post by **jeffball610** » Sat Feb 26, 2011 6:49 pm

All of this sounds like maybe the base timing isn't set right. I believe the closed throttle switch tells the ECU to use certain timing maps and such. Remember the ECU needs to have a wire grounded out to set the timing and idle. It tells the ECU not to mess with things while you get the base settings in. After you take off that ground wire, it will play with the settings you have to make it run like it thinks it should.

I'm sure you knew all of that, but just in case you missed something, go back and double check.

garden1 · Post by **garden1** » Sat Feb 26, 2011 8:20 pm

My base timing seems to be correct but it wont hurt to check it. Just need to borrow a timing light. this whole setup did come out of a 90 lazer fml. Thanks for your suggestion.

garden1 · Post by **garden1** » Mon Mar 07, 2011 6:30 pm

My idle being high was the problem. once the ecm saw the closed throttle switch actually closed, and there was high idle it tried to retard timing, causing that irratic idle. once i got the rpms around 700 (closing the base idle screw) the timing went down to 5 degrees btdc. The reason why i couldnt tell if the idle was abnormal was because i didnt have the exhaust hooked up. Man i feel like an dumb ass. Thats how you learn though.