I need a genious Options

[Gtguy22]

So some of you have followed my progress with my 94 2.2 gt. I had put a jdm engine in the car. Since i did so, the idle has been too high, around 1500-2000 cold start then down to 1000-1300 warm. I tried vac leaks, map sensor, mass air flow sensor, checked timing, i am completely stumped, the car is running really rich and poorly. Its killing my gas milage, and im out of ideas. PLEASE HELPPPPP

[GrimReaper]

In the case of a faulty temp sensor, the ecu will not light the check engine indicator (unless there's a cut wire).

If the temp sensor reads an inaccurate temperature, the ecu have no other way to know if it's accurate or not, it will assume that this is the exact temperature. The air/fuel ratio will be too rich (or too lean, depending on the situation) and the car will have rough idle and poor performance, depending of the situation again.

2 ways to check it, 1st, with a scan tool to see if the temp readings are close to the ambiant temp. You must have it checked cold (cuz your problem is about cold fast idle). With apropriate scan tool connected, start the engine and watch the readings to see if it's close to reality.

2nd, with a multimeter, check the ohms refering to a chart with the ohms/temp values of that particular brand/model.

Faulty temp sensors can have accurate readings in some temp range and inaccurate readings in other range, so you have to check it in it's full temp range, from very cold to fully hot.

I strongly suggest to have it checked by your local shop with a scan tool, it's much more accurate and it will cost you only a few bucks.

Hope you'll find your problem soon. Let us know, it might be helpfull for others.