The 4L60E has a problem with a valve wearing a bore in the valve body. This could be the problem (assuming that there is not with the programing). You can send the converter back to TCI and we will cut the converter open.

Kevin Steele
TCI
Product Engineer

 

I was cruising the car into Shaumburg the other night and started having some lock up problems. The Car has a TCI 3500 Super Street Fighter, and the TCI shift kit. The car probably has about 500 miles on the TC and shift kit.I was cruising at about 80-90 when it started locking and unlocking every couple seconds. It does it at all speeds where lock up occuts. The shifting of the tranny seems fine, all the shifts feel nice and firm. Just doesn't want to stay locked. I checked the fluid level and thats fine, and it doesnt smell or look burnt. What do I need to look for? Is it a trany prob, PCM prob, or TC? Thanks for any help that can be offered.
Bill

 

I had the same problem. It is pcm related. MMS changed my lockup program and now it locks up in third at 35mph and is very smooth on the highway.

 

Is it something that came after time, because this is the first time its acted up. I had the PCM tuned by Speed Inc to get the Vats and everything removed, and they set everything to the mods I had (i.e the convertor and gears).

 

What wire goes to lock up the convertor on a 98 Trans? If I can ground that out and it stays locked up all the time it would be a PCM prob right? Any opinions?

 

That's a common tuning issue. Normally not hardware related. Ragtop 99 can tell you what you need to do with Edit to fix the problem.

 

Have you a-tapped? Do you have a P0300 code? Even if Speed Inc tuned out the code, unless Jim maxed out the misfire tables to 32,XXX in the idle and low rpm tables you will still have lock up issues if you have any misfires.

Jim @ Speed is aware of how to fix this. I talked to him about it over a year ago when I tried it on my car. If he already did that, then I'd look to hard parts as the issue. First, ask Jim about your idle and low rpm misfire tables though....

EDIT: I just realized that you have a '72 car with this LS1 setup. Not sure what type of custom program you have then. What I just recommended my not apply, I don't know anything about how the hybrid PCMs are set up. You'll have to talk to Jim.

 

I dont have a PO300 code. Only codes i have are for the cooling fan relays, because i dont have them hooked up. I noticed that when it is locking and unlocking the speedometer is fluctuating even though my speed is consistent. Could Ihave a bad VSS sensor? Is the lock up based off of VSS at all?

 

Common problemb G.M. did not fix till '02 to my knowlege. Take to trans shop to install sonnax tcc valve. It will require removal of valve body and reaming bore, but should take care of L.U. woes