Ben,

Did you perform a CASE on the car after you installed the cam? Have you put race gas in it to see if your KR is eliminated or reduced?

i thought you didnt have to for a 97, or is that just for a pcm?

You must always perform a CASE if you change the cam, crank/cam sensor, or PCM. The 97'* have a knock module that can be transfered from the old PCM to the new PCM but that does not guarantee that you won't have to do a CASE.

No CASE learn was performed. The car fired up and ran just fine, no stumbles or anything. All seems to be fine other than when the torque converter locks.

I'm not running race gas, but the KR is there whether I'm using 91 or 93 octane. It has to be something related to the torque converter, because there is no KR until the TC locks in 3rd. You can drive in 1st, 2nd, or 3rd gear with the TC unlocked and get 0 KR, at any RPM. But when the TC locks and 'bogs' the engine down there are regularly 4-5 degrees of KR, with spikes as high as 10-12 degrees.

My AFC has me running rich everywhere in the powerband right now, so it'* not a fueling issue. LTFTs are consistently rich throughout all speeds and RPMs.

Todd, do you think this isn't a "flash KR" issue? Whatever it is, I want to make sure my trip to Ohio isn't in vain, ya know?


EDIT: Would a CASE learn help this situation? If yes, can you explain a little?

KR is most likely to show up when the motor is under the greatest load, that would be 3rd or 4th with power applied and the TC locked up (as your mentioning). If your PCM does not know the crankshaft variation you could very well be asking for almost +6 degrees of more timing than you want and that could certainly result in KR especially on a higher compression motor.

Your first step should be to get a CASE learn done on the car. Your second step should be to scan the car when it is having the problem and log everything you can so we can take a look at whats happening.

So aside from doing a CASE learn, do you think it'* alright for me to show up on the 14th with the car in current form? (i.e., should I be changing any parts or checking anything else?) Also, does that affect the time you would like me to show up at your shop?

And by the way Todd.... thank you for checking in here to make sure I'm doing things right. I appreciate it greatly.

Well wouldn't you know it..... the dealership wants $75 for a simple CASE learn. I had a nice, polite conversation with one of the techs and explained that I was only looking for a 5 minute procedure... he was polite as well, but wouldn't budge on the price. I'll call a few other places.

Todd, if I can't get an affordable CASE done in my area, would it be alright to bring the car as-is on the 14th? Maybe budget a little extra time for scanning and dianosis, and have you guys do the CASE?

Ben,

I'd like to make sure its a tuning issue and not soemthing more serious before making you drive all that way. Do you know anyone in the local gp club with an hptuners or dhp powertuner? I think they can do CASE learns....

Yeah.... I thought of that right after my post last night, lol. I've got a local GP guy with a PowrTuner helping me, but now we've got an issue with the gear selector. Read about that issue here.

Some good tips for you Ben from Todd. No doubt you're going to have to work through some of the possible causes in a methodical way in order to rule them out or identify them as the cause.

If you work with a DHP Powrtuner for the CASE Learn, you may have better success doing the proceedure in Neutral as opposed to Park.

Cheers,