Cascade Crew

[BigDaddyVu]

My iroc has a slight miss or its more like a stumble on idle after starting it warm or cold (it clears out after 1k rpms) then after 5 mins of driving at idle at a light it dies but after then a quick restart it runs like a champ. i have new iac, maf, tpi, dizzy, coil, plugs, wires, and o2. it only does this when its cold and humid. i wonder if the bar sensor may have an effect on it.

[blue89]

Have you checked the timing?

[Twilightoptics]

[blue89]

I would disagree. I think the 89/90 TPI car's had both a MAF and MAP but went back to MAF in 91 or 92. Prior years were MAF as well.

[Twilightoptics]

[chevymad]

I think all the map cars take a baro reading off the map sensor b4 the engine starts. LG4's dont because the sensor isnt a true map, its a vacuum sensor. They read backwards.

[blue89]

[91RSVert]

Alot of your newer cars do have map and maf. Partly because where one doesnt work well, the other does. Also for backup.

My gp has dual, your L31 should have dual also.

[BigDaddyVu]

[quote="Twilightoptics"]

[Dewey316]

Do you have a scan tool, or way to datalog. I would look at what the sensors are saying, it could be that your coolant temp sensor is sending bad data, and then overfueling the motor.

[BigDaddyVu]

by any chance you know the exact location of the sensor?

[Dewey316]

It should be someone near the t-stat, not sure exactly where it is on the TPI cars, but the ECU should get the temp from somewhere in the intake. Not much you can find out by just finding the sensor, you need to find out what temp. the computer is seeing.

--John

[Twilightoptics]

You need to see the values before parts swapping. On a TPI motor the ECM CTS is on the front of the intake next to the cold start injetor switch.