I went and checked for a 5v reference from the Black wire and got hardly anything, 32mV. The resistance at the black wire is still around 50 ohms. The resistance at the yellow wire is off the scale but it has continuity. What does this mean? Also, at what pin does the black wire connect to the ECM, I know the yellow is 10 but not sure about the black. I checked for a 5v reference from the TPS and I got 5v dead on. However, this was from the grey wire, not the black as you said. Did you mis-type??

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"If they do not run, Then they will die." - Stonewall Jackson

'87 IROC, 355 TPI, Converted to SD, 700R4, B&M Megashifter, 3.42, Trick Flow Twisted Wedge Heads, Comp Cam, Comp 1.6 Rockers, Lucas 23# injectors, Edelbrock headers, Flowmaster 3'' exhaust, gutted cat, Mallory coil, Mallory HyFire IV ignition box, Mallory Sidewinder 8mm wires, Autolite platinum plugs, K&N filters, Transgo Performance Shift Kit, Corvette Servo, 2,000 Stall Torque Converter

[This message has been edited by irocbsa (edited February 06, 2001).]

 

IROC,

You are correct. Not only did I mis-type, I gave you the wrong data for your car and ECM

The black wire is the signal ground for the CTS and other sensors. You should be able to read almost no resistance to ground on this wire. The yellow wire should have a 5 VDC reference voltage on it with no sensor connected. The voltage will drop depending upon how much resistance is connected.

The gray wire on the TPS should have a constant 5 VDC supply. If the voltage is present, the ECM supply is O.K.

If you are still reading resistance along the black wire, between the sensor socket and the ECM connector, the wiring is still suspect. The black wire should be connected to terminal 'D2" at the ECM. The same terminal is connected to the black wires at the TPS and MAT sensors. A quick check might be to measure resistance between the CTS socket black wire and that at the TPS socket. There is a splice in the wiring harness somewhere between the engine and the ECM, but I'm not sure where it might be located.

Sorry about the incorrect information. The above data is correct for your engine, however, as long as you're talking about the '87 TPI.

I'd post a photo of some of the factory splices that you can find in the harnesses, but my server is down right now - thanks, Mr. Gates.... You'd be underwhelmed with some of the splices.



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Later,
Vader
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"I know how to solve your problem, but I can't tell
you since you might use the information illegally..."
Adobe Acrobat Reader 4.0

[This message has been edited by Vader (edited February 06, 2001).]

 

Hey, thanks again man. I found one splice in the black wire but it looks like it goes to the MAT since the other wire is also black. In case you didn't notice in my sig, I'm running a speed density conversion integrator from Street and Perf. Is this info still correct?? I am assuming that it is since I still have the factory harness. I tested resistance the PROPER way at the black wire today and got none between the sensor plug and the ECM harness pin D2. As far as resistance to ground, I got an off the scale reading on both wires. Can I replace the entire wire, from sensor plug to ECM?? I don't see how the wires could be bad if there is continuity the whole way through on both of them??? What am I not understanding here. I'm at the end of the road as far as knowing what to do. Thanks.
bsa

[This message has been edited by irocbsa (edited February 07, 2001).]

 

ttt