i have a 1985 corvette the tps is not sending a signal to ecm how can i fix it put new tps new plug on tps set the tps at 5.4 v help 856-207-1767

 

Hint: Don't post your phone number to the entire world.

 

The TPS should be set to 0.54 volts, not 5.4 volts. I assume that was a typo...

Actually, the reference voltage for the TPS is 5.0 volts, so you couldn't get to 5.4 volts anyway.

Just to check everything, ground your meter to some metal part of the engine. Back probe the TPS connector while it is connected to the TPS. Ignition on.
Measure the top TPS wire (should be 5 volts).
Measure the middle wire (should be 0.54 volts at idle -- throttle closed).
Measure the bottom wire (should be zero volts -- ground).

How did you determine the TPS signal wasn't getting to the ECM? Did you measure it? Did you use a scanner? Did you get an error code? Some other way I didn't think of?

 

Look at your TPS connection to ECM in this link. Then if need be, run your own wiring to the proper ECM pins.

http://www.google.com/imgres?imgurl=...QEwAA&dur=3647

 

no kidding

Now we know you are in Cumberland County, NJ

 

[QUOTE=Cliff Harris;1584731420]The TPS should be set to 0.54 volts, not 5.4 volts. I assume that was a typo...

Actually, the reference voltage for the TPS is 5.0 volts, so you couldn't get to 5.4 volts anyway.

Just to check everything, ground your meter to some metal part of the engine. Back probe the TPS connector while it is connected to the TPS. Ignition on.
Measure the top TPS wire (should be 5 volts).
Measure the middle wire (should be 0.54 volts at idle -- throttle closed).
Measure the bottom wire (should be zero volts -- ground).

How did you determine the TPS signal wasn't getting to the ECM? Did you measure it? Did you use a scanner? Did you get an error code? Some other way I didn't think of?[/QUOTE

yes i got a code 21 but the light will go off than will come back on i really think the ecm is bad when the light is off the car runs fine when the light is on the car bogs down and it loses power like it miss fire and pinging i did change the pig tale and the volts was 5.4 on the top one and 5.4 on the middle the bottom was 0 unless my meeter is bad but i just got it and i got the code by the a and b port when i turn the key on first i got a 12 and it flashed 3 times then i got 21 the service light keeps going on and off

 

where is the ecm located on this car been looking for it its not under the hood from what i can see

 

i know was not thinking when i did my post

 

ECM location

http://forums.corvetteforum.com/c4-t...on-1985-a.html

 

The ECM is mounted in a tan plastic bracket that is bolted to the firewall under the dash on the passenger side. Take off the passenger side kick panel (several 7mm screws) to get to it. The ECM is held in the bracket by two 10mm bolts. You must remove the two connectors to get the ECM out. The connectors have latches that must be released to remove the connectors. Earlier connectors have a metal latch that must be pried up to release it. Later connectors have a plastic latch with a handle that you squeeze to release.

Here's a "top view" with the dash pad off. The two black pointy things are part of the ECM. They guide the ECM into position. The tan rectangle is the ECM bracket: