jamesbob02

My car is getting terrible shudder that feels like its in the driveline in 4th gear, around 45 mph, with light to medium throttle. My initial guess was that the TC was locking and unlocking rapidly, so I took an ALDL log and it looks to me that the problem only happens when the TC is actually locked up, and it's not unlocking and locking like I thought.

I know you can ground out the ALDL terminal and make it lockup all the time, but is there a way that I can turn off the lockup temporarily, without changing it in the PROM? I don't currently have the capability to burn chips, and I can't wait for someone else to do it for me.

Also, I have a full log, with all the other values, if someone is willing to look at it and help me figure out what may be going wrong. Here's and example log below.....I started from a stop sign and went full throttle to about 60, and the car ran fine, but when I slowed down to ~45 and allowed 4th gear and TCC lockup, I got the shudder between, about, seconds 66 to 70, until I put in more throttle and shifted down.

Thanks!

Apeiron

Unplug the connector.

Trickster

It's located on the left side of the tranny pointing down into the tranny pan. Careful, that plastic connector does get brittle with age, fluid, & heat. So does the adaptor plug it goes into.

jamesbob02

Thanks guys, I'll give it a try. However, upon further inspection of the log, I think there's something else wrong. My car is throwing a code 43: ESC system failure, but I've had that before and it was false, I know there's nothing wrong with the new knock sensor or any of that circuit, or the computer or memcal, because all were replaced before and the code was still there.

Still, in that area I was talking about where I'm getting the shuddering, my spark advance drops to around 20, and my knock retard goes up to its maximum during the run, of 20.4 and hovers there. Also, my injector pulse width QUADRUPLES, MAP pressure TRIPLES, BLM shoots to ~144. All of these things are in sharp contrast to before and after this "shuddering" time in 4th gear with lockup. For note, my knock count was stuck at 6 from the time I turned on the car til I turned it off.

I HAVE NOT tried to go beyond about 50, because I'm worried about the car, but I may try to take it on the highway and see what it does around 60-70.

If any of you guys that read ALDL logs a lot want to look at this, here's my log that I've cut down to include most of the important stuff, it's in Excel 2000 format. I don't know enough about this stuff to be able to pinpoint what's wrong. I've got the full log, too, if anybody needs it to help.

I'll reset the code and see if I can't log at what point it happens.

Thanks for the help.

http://students.ou.edu/R/Jimmy.D.Rob...art of run.xls