Sudden idle issue after fixing heater hose leak

The other day, the clamps holding the heater hose broke, so replace them and it fixed the leak. After that, my idle was off, car would stall. I adjusted the idle higher with the screw on the throttle body so it doesn't stall. Tried various things, unplugging the two things over the heater hoses on the fire wall, didn't change anything. Might have knock something while working on it, but can't find anything.

It is worse when cold, it doesn't even idle higher than when hot. Car runs fine otherwise, but exhaust smell like unburned gas at idle, must run super rich.

Any idea?


edit: the car is a 92 GT-Four JDM by the way.

I've been digging into fuel trim issues as well, and all of the standard stuff applies: O2 sensor, Air Flow Monitor, Intake Air Temp Sensor, Coolant Temp Sensor...

This is an utterly unscientific stab at this. Disconnect the battery and see if the ECU relearns idle conditions?

Do a vacuum leak test with throttle body cleaner?

Also which way did you turn the screw on the throttle body to raise the idle?

Roreri":2mvdark9 said:

I've been digging into fuel trim issues as well, and all of the standard stuff applies: O2 sensor, Air Flow Monitor, Intake Air Temp Sensor, Coolant Temp Sensor...

This is an utterly unscientific stab at this. Disconnect the battery and see if the ECU relearns idle conditions?

Do a vacuum leak test with throttle body cleaner?

Also which way did you turn the screw on the throttle body to raise the idle?

Click to expand...

Yeah, I thought about the ECU, disconnected the the battery and it changed nothing. To raise the idle it was counterclockwise.

I don't understand how it came after I fixed the the hose. It also came back to normal for a few minutes while I was driving. I thought I might have disconnected a vacuum hose, but I can't find any. Might be a cracked vacuum hose too. Is the cold idle vacuum actuated?

I believe cold start is triggered by a switch on the coolant tree. I assume you burped the coolant after fixing the leak and topping it off?

underscore":crtlvssw said:

I believe cold start is triggered by a switch on the coolant tree. I assume you burped the coolant after fixing the leak and topping it off?

Click to expand...

Yes, I did it and then the shop did it too with a service machine. Maybe I disconnected something or wires were damaged and holding by a thread. A few months mechanic that worked on my car broke the temp gauge sensor wire. The shop that fixed it said it looked like the loom was damaged and the fixed that wire. I'll take a look there.

To go off like that and to temporarily come back, must be electrical.