Hey guys, the 87 t2 i just picked up won't idle when warm. I bought it, figured it would be an easy fix... the clutch was easy. it was new, but it just needed a new pilot bearing... 10 bucks to fix :P

Anyways, it starts good, runs fine up until the temp needles starts to move into the operating range, and all of a sudden the idle drops to 200ish, and bounces around there for a few seconds before it stalls.

I checked resistance on the tps, it's a tad out of spec, but shouldn't be enough to keep it from running. Turning the BAC valve screw doesn't seem to do much either. Anyone have any experience with this?

Dirk


P.S. Maybe i should mention the 02 isn't connected right now either...

 

doesn't the o2 have to be hooked up

 

OK, update time. I wired in the 02 sensor, made no difference. Checked voltage on it, it's within spec.

I put a brand new coolant temp sensor in it, made no difference. Even checked voltage at the ECU, it's within spec.

So I went back to the TPS. Here's what I found:


Terminals.....Mode..........Spec...............Actual
A&B.............Idle........1000 ohms........780 ohms
A&B.............WOT.......4k-6k ohms.........7k ohms
A&C..............Idle........4k-6k ohms.......6.6k ohms
A&C.............WOT.......4k-6k ohms........231 ohms


... and that was as close as I could get it. So it looks like I need a TPS?

I also can't find the check connector for the TPS, or the idle mixture screw. I know where they should be, but they're just not there

 

Put a voltmeter on the O2 sensor output. Read what it is when it is running (cold), and how it changes when it stalls. Anything over 0.45v is rich, less is lean. I suspect that once the temperature switch tells the ECU to go into closed loop mode that your mixture is going too lean, and that is causing it to die. Normal operation is for it to maintain a rich mixture during idle and acceleration.

If this is true, then you have to figure out why it is going lean. Possibilities might include:
1. Vacuum leak (letting air in that the air flow meter did not measure)
2. Clogged primary injectors
3. Inoperative injector
4. Boost sensor
5. Air pressure sensor
6. Bad/disconnected air flow sensor
7. ???

Any codes?

There is a nice troubleshooting procedure in the FSM which details what to check for 'stalls when warm'