I did the search through the archives and found a little. I have found in my painless wiring kit a wire for VSS? and on my passenger side cyl head a sensor. I was under the assumption that an 89 IROC was cable driven. Which i have seen behind the dash. And i'm confused what the 2nd sensor on the pass. side head is for. I have one on the manifold in the coolant passage and one on the drivers side head in the coolant passage what's the one on the passenger side for? Reason i'm asking is because in the archives i read that the Torque Conv. won't lockup if it doesn't see the correct temp. I was also wondering if maybe the VSS wire had something to do with it also? I hate doing 2,000 RPMS @ 60 w/ 2.77 gears. BTW i know the Torque converter isn't locking up because i installed a temporary switch to test and see if it was. And it wasn't @ 55 the rpms went for 1600 or 1700 to 1500 or 1400. But the car kind of bucked when i had it lockup up for maybe 10 - 15 seconds. Thanks, Any help is appreciated.

I posted this in the Transmission/Drivetrain board with no responses.

 

The sensor on the front of the block is the CTS, driver side above plugs 1&3 is the guage sender, pass side has 2, one is the aux fan switch and the other larger one is the knock sensor. 89 has the VSS on the speedo unit driven by the speedo cable. The cable turns a Hall generator which goes to the VSS buffer module and in turn to the ECM. If the speedo cable is bad or disconnected the converter won't lock and the ECM will throw an SES light with a code 24 after approx 10 min or so of driving over 35 mph. 2 things need to happen for the converter to lock. Coolant temp has to reach approx 105-110 (closed loop engine control) degrees and you have to be over 35 mph. Both functions are controlled electronically by the ECM. The ECM drives a solenoid in the transmission to control lock. Also, remember the brake switch is also in series with the 12volts that feeds the lock solenoid as pushing the brake pedal down slightly causes the converter to unlock. The only coolant sensor in play for TCC is the CTS on the front of the block, it should be the 2 wire one. Guage sender, KS, and aux fan sw have only one wire. They have no effect on trans control. More info would help as you mention the Painless wiring. What did you change?

 

Thanks for replying. So since i did not hook up the VSS wire for my tach because i figured "It's cable driven why should i need that..." the ecm might not be locking the converter at all.

 

Correct. The VSS is actually inside the speedo head. Later models have the VSS mounted at the trans in the same place as the present cable unit. Later models used a fully electronic speedo.