idle/ starting problems when hot

[PKRWUD]

You really need a breakout box to properly diagnose this one, but two things you can look for are a short to ground in your spout circuit, or in your O2 sensors wiring. A bad TFI module is also possible, but doubtful. If you have a known good one to try, go for it, but don't buy one. There is one other possibility, but it's tougher to check. The wire that is the second from the bottom in the connector that goes to the TFI module (should be dark green with a yellow tracer), goes to splice that goes to the negative side of the coil in one direction, and to pin 4 on the ECM in the other direction. The wire that goes to the ECM has a 22k ohm resistor inline, and if that resistor goes bad, it could cause similar problems. To test it, you need to disconnect the harness from the coil, the TFI, and the ECM, and measure the resistance between pin 4 at the ECM harness connector, and the pin at the TFI connector that has the dark green wire with the yellow tracer.

Take care,
-Chris