TB adjustment screw and TPS voltage

Wall96cobra · 05-03-2005, 11:44 AM

I've been told you should NOT mess with the adjustment screw on the throttle body (which I did to keep my car from going dead after the tune). Someone was saying it could mess with the TPS voltage but I can't see how it could. Has anyone ever heard this?

rtusnake · 05-03-2005, 11:52 AM

I've never heard that before but i guess anything is possible. I have adjusted mine as well and seems to be fine. Maybe someone else knows

Italian LX · 05-03-2005, 11:59 AM

Quote:

Originally Posted by Wall96cobra

I've been told you should NOT mess with the adjustment screw on the throttle body (which I did to keep my car from going dead after the tune). Someone was saying it could mess with the TPS voltage but I can't see how it could. Has anyone ever heard this?

It could change the voltage at "closed throttle" slightly (the voltage would read a little higher). However, I don't think it would be high enough to wreak any havoc on how your car runs. Most TPS sensors I have checked read a lot lower at idle, so unless you have adjusted yours, it's probably still below where it should be.

Wall96cobra · 05-03-2005, 12:11 PM

Quote:

Originally Posted by Italian LX

It could change the voltage at "closed throttle" slightly (the voltage would read a little higher). However, I don't think it would be high enough to wreak any havoc on how your car runs. Most TPS sensors I have checked read a lot lower at idle, so unless you have adjusted yours, it's probably still below where it should be.

That's how I was looking at it. As long as my car idles ok then I don't see a problem or how it could affect part throttle or wot driving.

86GT · 05-03-2005, 12:13 PM

The TPS on the 86-93 cars needs to be under 1.0 at an idle. Most people will adjust the idle set screw and then ream out the mounting holes on the TPS to adjust for a voltage of .98 or so.

As for the 94+ cars the EEC takes a snap shot of the TPS value at startup. This then becomes the idle TPS value until the car is restarted. If it were me I would still not let the TPS value get above 1.1.

Wall96cobra · 05-03-2005, 04:08 PM

Quote:

Originally Posted by 86GT

The TPS on the 86-93 cars needs to be under 1.0 at an idle. Most people will adjust the idle set screw and then ream out the mounting holes on the TPS to adjust for a voltage of .98 or so.

As for the 94+ cars the EEC takes a snap shot of the TPS value at startup. This then becomes the idle TPS value until the car is restarted. If it were me I would still not let the TPS value get above 1.1.

So is there a certain voltage or range it needs to be in the WOT position also?

86GT · 05-03-2005, 06:24 PM

No, The WOT depends on the TP breakpoint. The TP breakpoint is set to 2.7 from the factory. This is then added to the idle TP to get the final WOT voltage. This would normally be around 3.7 volts.

I have my TP set at 0.98 at an idle, and it goes to 4.73 at WOT.

05-03-2005, 11:44 AM	#1
Wall96cobra ooooo cake!!! Join Date: Dec 2004 Location: Saks, AL Posts: 1,630	TB adjustment screw and TPS voltage I've been told you should NOT mess with the adjustment screw on the throttle body (which I did to keep my car from going dead after the tune). Someone was saying it could mess with the TPS voltage but I can't see how it could. Has anyone ever heard this?

05-03-2005, 11:52 AM	#2
rtusnake Halfshaft Killer Join Date: Mar 2005 Location: The Kingdom Posts: 3,910	Re: TB adjustment screw and TPS voltage I've never heard that before but i guess anything is possible. I have adjusted mine as well and seems to be fine. Maybe someone else knows

05-03-2005, 06:24 PM	#7
86GT Member Join Date: Mar 2005 Location: Sacramento California Posts: 449	Re: TB adjustment screw and TPS voltage No, The WOT depends on the TP breakpoint. The TP breakpoint is set to 2.7 from the factory. This is then added to the idle TP to get the final WOT voltage. This would normally be around 3.7 volts. I have my TP set at 0.98 at an idle, and it goes to 4.73 at WOT. __________________ EEC Analyzer A9M, TwEECer, 306ci, 73mm C&L w Tuner Tube, Cobra Intake, 42# inj, Edelbrock 6037, E303 cam, 155 fuel pump, FPR, 70mm TB, E-Fan, 3.55 gears, Powerdyne 9psi actual 5psi...way more.