No 4 volt sensor.

[scooter]

All my sensors have only 1volt in. If i unhook my tps, it goes to 4v. I cut the wires and ran new straight to the ecm, but it still drops voltage when i connect my tps. I tried two different tps.

Any ideas?

Thanks, todd s.

 

[cammeddrz]

i thought that the tps read like .6v (or something) at idle and then full voltage at w.o.t. the ecm should have a solid-state circuit that drops voltage as soon as the tps is hooked up and it sees that resistance

just for kicks hold the throttle wide open and then check the voltage. i could be wrong but its an easy, and free way to rule things out

 

[scooter]

i thought that the tps read like .6v (or something) at idle and then full voltage at w.o.t. the ecm should have a solid-state circuit that drops voltage as soon as the tps is hooked up and it sees that resistance

just for kicks hold the throttle wide open and then check the voltage. i could be wrong but its an easy, and free way to rule things out

.1V out, but constant 4v in to the sensor, in fact most of your sensors are 4v.

 

[cammeddrz]

really your 5.0 is .1v at idle? wow that sounds low but every manufacturer is different. is it a 3-wire tps?, either way what does it read at w.o.t. ?

 

[scooter]

really your 5.0 is .1v at idle? wow that sounds low but every manufacturer is different. is it a 3-wire tps?, either way what does it read at w.o.t. ?

Yes that is low, supposed to be .7-1.0V at idle, that is my problem..........

I have tore that wireing harness out completely, and installed a different one. I am not sure whats wrong, but it has to be in that harness.

 

[BRUTUS_T_HOG]

how is the ground for the TPS? shorted connector?

 

[scooter]

No ground. one wire is 5Volt, the other is sig return ("common" wire goes to allot of the sensors then back to the ecm), and one is the actual "position sensor" wire (green). they all three go to the ECM, no chassis ground.

I cut the connector out completely......

 

[cammeddrz]

don't get upset at me mentioning such an elementary suggestion, but my tps always reads really low until i adjust it does the voltage change as you open the throttle? you haven't really answered that yet

 

[scooter]

Im not upset. Sorry.
If i have 1 volt goin in, you can quess how much voltage i have at WOT. 1 volt.
I only have 1 volt in not 5 volts. Tps is not the problem, its in the wiring harness. Put on a new harness and ecm. We will c if it fixes it or what.

THANKS, Todd S.

 

[fordmike1]

Is the ground on the engine harness grounded? There should also be a ground that is bolted to the back of the head with the engine harness and it should go up to the firewall. You should have a ground that hooks to the batt. neg. and then to the fender and another one that comes right off the computer with a bare wire that grounds the wires coming from the distributor. Make sure that all of these grounds are clean and bolted down tight. See if this helps you any.

 

[scooter]

Ok got the new harness in and hooked up. Runs, but had a miss at idle. I will work on it more tomorow.

THANKS FOR ALL THE HELP.
Todd S.