dmcindiana
07-03-2023, 01:04 AM
Hi, everyone. Quick background.
Pretty new owner here. Got 10620 in April. One of the teeny-tiny clean-ups I wanted to do was reattach the rear 5-module cradle to its metal bulkhead. It was just sitting loose, unlike the front cradle. Relays had to come out to do that. Attached successfully, put the relays back. Went to a car show that weekend, then drove it to work on Monday. No problem. Leaving work, 2 things start happening kind of simultaneously. The first is that the engine dies at every stop. I get the car safely off the road in someone's driveway, and I'm sure it's a latent loose-relay issue. So I give all 5 rear ones a little wiggle and then I get the second issue, which is that nothing happens when I turn the key. I give another wiggle and I can get it started again, but the dying at every stop is consistent all the way home.
At home, I pull the relay cradle out again, and it was clear I had pushed a starter relay contact out. Fixed that. Idle problem remains. Went through 2 basic checks I read about on here. Idle speed motor opens and closes the way it's supposed to when the key's in the second position. RPM shoots up when I disconnect the right ECU connector, engine running. For the 3rd basic check, I did the Dave M. recommendation to adjust curb idle. Hot engine, adjust in till it goes just above the 775 then back out slightly. Then I had to adjust the upper screw for the microswitch, which wasn't closing as a result of the curb adjustment. That appears to have done the trick. I should mention that the position the curb screw was in before I adjusted was such that I could not slide a piece of paper between the screw and its resting surface, but if I opened the throttle to slide the paper in and released, I could slide the paper back out without tearing it. A little yank was required, but no tearing. Same thing hot or cold.
Question 1: why did this work? After a sudden release of the throttle, the RPM still dips below normal idle before recovering. Why would it matter where the curb idle is set? Am I not masking a problem in the idle circuit by increasing curb idle? Is it that a slight increase of curb idle results in a matching increase of minimum downswing after sudden throttle release? And that's just the little boost that the idle circuit needed to work right?
Question 2: why the sudden onset? Both screws were rusty-crusty. There's no way either screw was backing out on its own. Has my recent driving jostled the entire throttle assembly just enough to back the adjustment arm out a smidge? Anyone with a similar experience? The PO put very little mileage on the car. I've just about hit his mileage in only 2.5 months. (What can I say, I'm enjoying the snot out of it.)
Pretty new owner here. Got 10620 in April. One of the teeny-tiny clean-ups I wanted to do was reattach the rear 5-module cradle to its metal bulkhead. It was just sitting loose, unlike the front cradle. Relays had to come out to do that. Attached successfully, put the relays back. Went to a car show that weekend, then drove it to work on Monday. No problem. Leaving work, 2 things start happening kind of simultaneously. The first is that the engine dies at every stop. I get the car safely off the road in someone's driveway, and I'm sure it's a latent loose-relay issue. So I give all 5 rear ones a little wiggle and then I get the second issue, which is that nothing happens when I turn the key. I give another wiggle and I can get it started again, but the dying at every stop is consistent all the way home.
At home, I pull the relay cradle out again, and it was clear I had pushed a starter relay contact out. Fixed that. Idle problem remains. Went through 2 basic checks I read about on here. Idle speed motor opens and closes the way it's supposed to when the key's in the second position. RPM shoots up when I disconnect the right ECU connector, engine running. For the 3rd basic check, I did the Dave M. recommendation to adjust curb idle. Hot engine, adjust in till it goes just above the 775 then back out slightly. Then I had to adjust the upper screw for the microswitch, which wasn't closing as a result of the curb adjustment. That appears to have done the trick. I should mention that the position the curb screw was in before I adjusted was such that I could not slide a piece of paper between the screw and its resting surface, but if I opened the throttle to slide the paper in and released, I could slide the paper back out without tearing it. A little yank was required, but no tearing. Same thing hot or cold.
Question 1: why did this work? After a sudden release of the throttle, the RPM still dips below normal idle before recovering. Why would it matter where the curb idle is set? Am I not masking a problem in the idle circuit by increasing curb idle? Is it that a slight increase of curb idle results in a matching increase of minimum downswing after sudden throttle release? And that's just the little boost that the idle circuit needed to work right?
Question 2: why the sudden onset? Both screws were rusty-crusty. There's no way either screw was backing out on its own. Has my recent driving jostled the entire throttle assembly just enough to back the adjustment arm out a smidge? Anyone with a similar experience? The PO put very little mileage on the car. I've just about hit his mileage in only 2.5 months. (What can I say, I'm enjoying the snot out of it.)