Si Corolla Problems

[nightblade]

Hi all

I have an Si 1.6 1996 corolla. If been trying to fix the starting problem for a while now and have been told that its a vacuum leak because there is high RPMs but from cleaning the throttle body, IAC valve and checking for leaks it doesnt seem to be the issue.

When the driving along when slip it out of gear to role the idle is still around the 1200rpm when the engine is warm. Another thing is that if i let the car in gear and reaches low rpm it chugs in 1st 2nd and 3rd gears, not 4th or 5th. The clutch is bad in it but its strange that it only does it in the first three gears. During the week while driving and the car was warm, the volt gauge didnt seem to be giving an accurate reading and was bouncing and also the heating gauge went right up (checked today and all the coolant is gone from the reserve tank even though there is no signs of leaks and only filled it in November) for about 10 seconds and then back down again and then stayed at normal temp, and the radio is being weird with the mp3 player and the bluetooth (the radio is only a few weeks old) by them both cutting out.

I did get it diagnosed in january and it came up with the MAP sensor so i changed that. He did say that it could be either the wiring or ECU as well.

Im starting to think that its all related to the ECU?

Has anyone had similar problems and found the cause?