1G TPS overvoltage

[Wilson76]

My 93 laser 1.8 5sp is currently having issues. It will randomly loose power, the RPM drop to about 2k, and then will only rev a few hundred rpm more before dropping back to 2k.

My father (a master mechanic and land speed racer) suggested it might be my TPS. I got out my multimeter and checked it, the input voltage is a whopping 11v and the idle signal voltage is 1.2v going up to 10.8v at WOT.

I read that the input voltage should be 5v and the idle voltage should be about 0.4v and WOT voltage should be about 4.75. Could this overvoltage be my problem and what can I do to fix the issue?

When the car looses power the CEL comes on but the only error code I get is a code 15 no signal to ecu from speed sensor. I'm really confused. Any help would be greatly appreciated. Thanks in advance.

 

[steve]

The 4G37 ECUs are different in many ways but you should see +5v on pin 23 Green/Red wire and ground on pin 24 Green/Black wire just like on the 4G63. The TPS output goes to pin 19 Green/white wire.

If you not and you're sure you have the right pins then check with the connector disconnected to see if the ECU is putting out 12v there or if it's coming from something connected to the harness.

I think code 15 is actually a fault in the 1.8L version of the Idle Position Switch next to the 4G37 ISC which is connected to the same sensor voltage and sensor ground as is the MAF.

Another way the 1.8L ECUs are the same as the 2.0L is in the capacitors leaking. You should check the condition and make sure there isn't any damage.