I'll try to make this short because I don't want to create a long post that will scare away help...there are a lot more details if they will help.

I could tell my power was slowly being sapped from the engine and decided to check the timing. Sure enough, it had slipped considerably. So I time it back to stock and it runs great again.

The problem is, I'm throwing a code 43 (ESC system failure, I know what this means) and getting an awful shuddering in 4th gear with lockup and medium throttle, around 45 mph. I've not tried to push the car further in 4th gear yet for fear of screwing something up, so the problem may or may not be ONLY around 45 mph and ONLY with medium throttle.

I've gotten a code 43 before and it was false and intermittent and went away....all the checks I've done are pointing toward another false code here.

I've got ALDL logs and can read and relay or transfer them as necessary, so where do I start?

Thanks!

 

Come on guys, I really need some expert help here!

 

Post the part of the log that has the problem in it. Is the distributor hold down coming loose? Anything else you've noticed??

 

I think it was a combination of a loose clamp and my tight plug wires (made4u looms and custom cut) that turned it. It's really tightened down now. There's nothing significant I've noticed.

I've been this situation before, where I've corrected the timing from ATDC back to stock, since the balancer ring had slipped and it took me a while to figure that out, and I also gained a lot of power then, but there was no problem like this. In fact, I was getting the false 43 codes when the timing was in the ATDC region, along with rough running and fuel combusting in the headers, making them glow, but ALL those problems went away when I corrected the timing.

Anyways, here's a log of a run from a stop sign at high throttle to about 60, then I drop down to the 40's and allow 4th gear and lockup. That's when the problem starts happening. You can see it in the fluctuations in the mph and rpm. It occurs during that 5 second interval that the TCC is locked up. There are some crazy contrasts between that region and just before and after it in knock retard, pulse width, MAP, and other things. I think someone more experienced than me would see something very wrong here.

The log is in Moates format with .csv extension. I can make it Excel if necessary. The important log items are in the HO-IO columns region, but everything's there if it helps.

Thanks for taking a look, here it is:

http://students.ou.edu/R/Jimmy.D.Rob...amaro/run1.csv

 

I don't know if this would cause the problem or not, however there is a 4th gear switch inside the tranny case that does go bad from time to time along with the TCC solenoid.

 

Anybody taken a look at the log yet?

 

Yeah I did. I bet it has something to do with the HUGE amount of knock retard you have. Get that taken care of and your car will probably drive alot better.

It also looks like you're having to put a lot of throttle into it just to cruise aka 40% throttle. I "think" that's due to the knock retard.

Are you running cheap gas? Do you have an aftermarket chip in there? Something is causing lots of knocks.

Here is a chart from your data. Knock retard in Degrees is in pink. Blue is RPM

 

Yeah I was seeing the same thing...but not sure what to think of it. It's possible that my ESC system really is messed up and is causing the weird knock retard.

As for the amount of throttle, that really is not a factor. Notice I was speeding up in 4th gear, low rpms....I know my tranny well enough to know how much throttle I can put before it downshifts. Basically, I was pushing the car into this "shudder" is thoroughly as I could to get a good reading.

I run 91 octane, but I could have gotten a bad batch of gas, I've heard of that happening, and people pull their hair out and the problem goes away with a new tank of gas, but would I see this ONLY in this region if it was bad gas?

As for the chip, it is stock tables with things like EGR, AIR, VATs disabled, so it's not that. If I had an AutoProm, I'd burn it to avoid the knock retard, but it's clear that would be treating the symptoms and not the problem.

There's not much gas left in it....I'll go around in D and try to run most of it though, and get a new tank. I know I can avoid the region if I absolutely have to. Also, I'll thoroughly go through the Helms manual flowchart for the code 43.

Something of note, though, that I would definitely like opinions on: You said that something is causing lots of knocks there.....yet my knock count is the same throughout the entire log....what does this mean?

 

Oh I've got another question.....how do you make that Excel graph with multiple y-axis data ranges so that you can view multiple sets correctly?

I was resorting to creating individual charts because anytime I factored in RPM, the new data range forced everything else to be unviewable, basically.

 

Yeah, I was noticing that the knock counts were steady but it kept pulling timing. Not sure how to explain that. I didn't realize you were trying to put that much throttle into it I thought you were just cruising under light throttle. I was asking about the gas and chip because many of the off the shelf chips just bump up timing which when mixed with low octane gas could hurt you.

I agree that it does look like something is messed up for it to be showing that much timing being pulled. Maybe someone else can chime in on it.

To plot on the second y axis, just double click the data line and click the "Axis" tab. Then there is an option to plot on a secondary axis.

I didn't notice anything else weird in the datalog but I'm far from an expert.

 

Well thanks for taking a look at it! I really appreciate it.

 

Well I took the TCC connector off and did a run, and that took care of the lockup shudder, which was exactly what I thought was happening.

HOWEVER, the engine still fluttered and struggled in that range, so my guess is the TCC shudder was a RESULT of whatever is screwing up the engine in that area, does this sound right?

I'll finish running a tank through it and checking on the ESC system, and I'll post again.

I think the main clue here is the knock count staying constant, yet a lot of timing is being pulled out in that range....anybody else have any suggestions?

Thanks.

 

I started going through the flowchart for tracing a code 43 problem, and the very first item asks to see if there is fixed knock retard between 4 and 20 degrees in idle, closed loop. It says this is to check if conditions for code 43 still exist, because if a code 43 is current, the system is supposed to apply a fixed 15 degrees of retard. Well, the ALDL reads ZERO knock retard, so the book says the code is intermittent.

Ugh, I don't know what to do!