Needed to install new crank sensor and IAC because car was stalling. The fuel pump & filter, ICM, coil pack, and plug wires are new too.
After install, the car fired right up. I chose one of the several IAC/TPS reset procedures out there and this is what I got at closed idle:
BLM 131
IAC 16
TPS 44
MAF 6
RPM 800
WOT 4.54
On the road, the car ran great with no stalls, but with just a slight stumble at 25...but it would continue on throttle with no other problems.
Last weekend, just for the halibut, I decided to get more experience tuning the car by trying a different IAC/TPS reset procedure to see if I could 1) match the good scan numbers I got last week and, as a separate thing, 2) track down a fix for the stumble.
So, I started the car and it idled great. Then I shut it off, and did one of the other reset procedures (clip into ALDL, unplug, plug in IAC, etc.).
Unfortunately, I did not have the engine in CLOSED loop before I began. I went at the reset procedure with an OPEN loop state. When I tried a restart, it ran several seconds then died.
So, I tried doing every other reset procedure out there (including the TPS and min. air screw adjustments). The best I could get was for it to run for a minute with me cycling the throttle, but it would die without my help...very frustrating.
Now, I'm puzzled. Since the car ran okay after the new parts were installed, what did that second reset do to the car that will not let it run?
How can I get it to run so I can tune it???
My only idea is to unplug the ECM, then check IAC pintle position, reinstall the IAC, unplug the crank sensor and crank the engine...then replug the ECM and try firing it again. That is how the car was set up when it ran after I first replaced the IAC and CPS.
Any other ideas out there?
Thanks for your help!
Steve
After install, the car fired right up. I chose one of the several IAC/TPS reset procedures out there and this is what I got at closed idle:
BLM 131
IAC 16
TPS 44
MAF 6
RPM 800
WOT 4.54
On the road, the car ran great with no stalls, but with just a slight stumble at 25...but it would continue on throttle with no other problems.
Last weekend, just for the halibut, I decided to get more experience tuning the car by trying a different IAC/TPS reset procedure to see if I could 1) match the good scan numbers I got last week and, as a separate thing, 2) track down a fix for the stumble.
So, I started the car and it idled great. Then I shut it off, and did one of the other reset procedures (clip into ALDL, unplug, plug in IAC, etc.).
Unfortunately, I did not have the engine in CLOSED loop before I began. I went at the reset procedure with an OPEN loop state. When I tried a restart, it ran several seconds then died.
So, I tried doing every other reset procedure out there (including the TPS and min. air screw adjustments). The best I could get was for it to run for a minute with me cycling the throttle, but it would die without my help...very frustrating.
Now, I'm puzzled. Since the car ran okay after the new parts were installed, what did that second reset do to the car that will not let it run?
How can I get it to run so I can tune it???
My only idea is to unplug the ECM, then check IAC pintle position, reinstall the IAC, unplug the crank sensor and crank the engine...then replug the ECM and try firing it again. That is how the car was set up when it ran after I first replaced the IAC and CPS.
Any other ideas out there?
Thanks for your help!
Steve