Doing a custom project. I installed an LT1 from a 96 Caprice into an 87 Fiero using a 4T60-E trans. Using a 95 LT1 PCM to run everthing. As you may or may not know, the LT1 PCM wants to see a 40 tooth reluctor ring for the VSS that spins at driveshaft speed. Well, the 4T60-E only has a 30 tooth reluctor ring that spins at wheel speed which means that the signal coming from the 4T60-E's VSS is going to be significantly less than what the LT1 PCM wants to see stock. Well, I figured Tunercat had this nice VSS adjusting tool so I would set it up for the 30 tooth reluctor ring that spins at wheel speed, or approx 24,000 pulses per mile. Well, the problem is, when I make the adjustment and reflash the PCM, the engine will not run. It starts, but then immediately dies just like if there was a problem with the PASS-KEY system. Well, I pull the program back off the PCM and undo the changes made to just the VSS tables and the engine runs again. So what gives? Is the PCM seeing something in the changes I make and deeming them to not compute? What do I do now? The Fiero has 245 40 18 tires on it (approx 800 revs per mile) and a 30 tooth reluctor VSS sensor. NEED HELP. The LT1 PCM needs to be able to shift the 4T60-E or I am going to have to add another PCM just to control the trans. Any help would be appreciated.

 

Where are you changing this? Is it in the constants? I am looking and don't see anything for a pulse per mile table in my TC.
Just trying to look at your problem,
Botch

Nevermind, I see where you were changing it. In the speedometer calibration tool. I dunno.

 

I talked to TC at tunercat. I screwed up and was using the revB "EE" .tdf for the 95 PCM. The "EEb" (revB) is for early 94 LT1 PCM's ONLY. That is why tables were offset and stuff was getting messed up. Got it fixed and it shifts the 4T60-E just fine. In case you are wondering how I wired the 95 LT1 PCM to control a 4T60-E, check out this diagram of what I did: http://dtcc.cz28.com/LT1Fiero/index.htm