getting 4.74 volts when trying to adjust the tps voltage??

[Guest]

[patd2345]

so i was trying to get my tps voltage within range and when i hooked up my meter it said 4.74 volts at he green wire, i moved the throttle and at WOT it went to 4.75, what is going on? about 2 months ago i adjusted it to around 0.98 and it ran good, the only thing i did to the car, is installed a clutch switch( the ford style i swapped out of a 4cyl mustang), it seemed to idle better with it all connected, before i had a wire jumpering the two plastic connectors making sure the touched all 4 metal contacts in the plastic connectors

[Joel5.0]

1. ........

2. Please add your locaton info to your profile......

3. The TPS does not need to be adjusted, as long as it stays within its functional closed throttle window of .7 - 1.1 vdc and no TPS related failure is present in a KOEO/KOER self test, no need to adjust it....... besides, the TPS is a non-adjustable sensor.

4. Disconnect the TPS and check the voltage readings between VREF and SIGRTN and TP and SIGRTN at the harness connector and LUK.

[patd2345]

i meant to say i was trying to get it under 1.00 volts... i unpluged the connector to the tps and and i got VREF:0.02V
Sig RTN: 4.76V
TPS: 4.78V

[Joel5.0]

I think the readings are mismatched however, you should only have one of the wires with 5 vdc at the harness connector....... could you post the reading/wire collor from the harness?

Looks like there's a short to VREF......... once you post the results/wire color I'll LYK what to check for next.

[patd2345]

alright here ya go
gray/red: 4.76V
gray/yellow: 0.02V
black/white: 4.78V

[Joel5.0]

gray/red: 4.76V = VREF
gray/yellow: 0.02V = TPS
black/white: 4.78V = SIGRTN

Based on the above, looks like theres a short between VREF and SIGRTN somewhere.

Suggest to leave the VOM connected to that wire monitoring voltage and disconnect the other sensors, one by one (EVP, BP, ECT, ACT) to see if the output drops to 0 vdc. If the output stays at ~ 5 vdc, also disconnect the clutch pedal switc and see if the voltage drops to 0 vdc. LUK

[patd2345]

ok i disconnected every sensor, and nothing, stayed at around 4.5V then i disconnected the clutch switch and nothing but when i connected a jumper wire i got it to go to .40V
hers the pics of what i did :


and i got

 
next i connected a jumper wire like i had before i installed the switch

and i got

the tps wasn't connected to TB so thats why the voltage is so low

[Joel5.0]

Here is the problem...................



The white/clear connector on the LH is the clutch pedal switch side for the ECM....... the Black/Wht wire is the SIGRTN wire shared with all the sensors. The black connector on the RH is the Clutch Pedal Safety switch for the starter...... if you cranked the engine with the jumper installed as shown, the SIGRTN circuit on the ECM PWB should have a section blown/burnt, due to the shock it gets from the 12 vdc START voltage pulse. The jumper to force an in-neutral condition should have been isolated to the two pins in the white connector.......... and if you wanted to be able to crank the engine w/out pressing the clutch pedal, the jumper should habeen between the two pins of the black connector ONLY. The reason why the TPS reads fine with the jumper wire installed as shown above, is because the ECM is "using" the ground from the starter solenoid body through one of the Red/Lt Blue wires of the black connector.

Suggest to remove the ECM, open it up, and check if it has a burnt/blown section of the SIGRTN line....... something like the example shown below......



LUK

[patd2345]

ok so it has always ran pretty bad to ok and couldn't figure out why, do you think this might be it, it had the surging and rough idle, ok so i pulled the eec apart and it looks like there is a break in a wire ot looked similar to the one in the pic you gave to me
hers some pics:

[Joel5.0]

Yep..... SIGRTN circuit is kaput...... need to do some repair work to restore that line and fix it like shown below.....



NM the way it ran, if you had run a KOEO self test, you would have a had a long list of "hard failure" codes  showing ....

[patd2345]

see thats the thing i couldnt pull any codes i traced all the wires to the eec and tested the resistance and they had no breaks and still couldn't get any flashes at all, is that whats causing it? and about a 3 months ago(the car never gets driven) with the jumper wire still installed i could pull codes and i got .96volts at the tps wire so im thinking it broke recently 

oh and for repairing it i just need to solder a wire in that connect the 2 posts together, the one each side of the break right?

[Joel5.0]

The only way the self test could be triggered, would have been by installing a jumper wire between the STI and a ground (instead of the SIGRTN wire at the VIP connector)....... Yep, restoring that line would do. Just make sure you don't install the jumper wire between the clutch pedal switch assy. connectors after the repair.

[patd2345]

update: i soldered the wire where the break was on the eec and made sure it had continuity and it did, bolted it up and installed it in the car, it started up and idled perfect and had excellent throttle response, it never ran better, then started to idle rough. so i did a base idle reset(the same procedure on this website) and the idle came back better no loping up and down, but it still idles like it has a aftermarket cam in it which it still has the stock one. i tried to pull the codes and got nothing again following the same procedure on this website, im stumped 

[Joel5.0]

Make sure you follow the jumper from STI to ground setup and LUK.