StevenB L98/LS1

Yesterday i just got done hunting down why my car has been running rich lately, and today i when i putting the throttle body back on i just noticed my TPS was at .65V. So i tryed adjusting it to .54V, but i can not get the adjustment any lower than .63V, and so i thought if i lowered the idle screw a little i could make the adjustment. Put there is a plate on the throttle body on the back of where the idle screw would be. So i cant adjust idle screw and i cant adjust the tps low enough to spec. Is there something im missing here?

Tuned Performance

iTrader: (92)

you can use a tps for 85-88 tpi they have elongated slots for adjustment 89-92 do not. the welch plug is installed from the factory over the idle stop screw. you can use a punch to remove it. the aldl jumper must be jumped to move the iac in and then the minimum idle speed can be set to 450

StevenB L98/LS1

So is my spec correct? Or still wrong? Will it really affect it that much being at .63V instead of .54V?

Tuned Performance

iTrader: (92)

.54 is the spec the voltage goes up when the throttleblades are opened. this could be caused by a worn throttlebody. binding throttle shaft or throttle cable. The increase voltage will cause the engine to run rich. you can elongate the holes in yours a little with a round file. you have a acdelco 213-908 style and you can adjust with a acdelco 213-905.

http://www.ebay.com/itm/ACDELCO-213-...#ht_1204wt_931

http://www.iroczone.com/2009/10/adju...on-sensor-tps/

skibum2100

I was under the impression that Speed Density (SD) systems, 90-92, don't need the TPS to be set to .54V. The computer just senses a baseline at startup that it uses for minimum idle. That is why yours in not adjustable. Please, please, somebody correct me if I am in error.

Use a DMM to ohm check your injectors.

How old is your O2 sensor?

Upgrade to a heated O2 sensor if you have headers.

Hope this helps.

Tuned Performance

iTrader: (92)

oh my bad, I was reading his profile name 1989 formula kid and thought we were talking about a 89 maf, yeas that is correct about the sd

StevenB L98/LS1

sorry about the confusion. i use to have a 89 formula, but got rid of that years ago, yes its a 91 TA Speed density L98. Ive done several different things to fix the rich condition but the tps when i was putting everything back in was above normal spec. So 90 above are not adjustable? Well it starts to make more sense now. Because the car is still running a little rich, not as bad as it was, but its still running rich, it doesnt bog down or die like its getting a overbearing amount of fuel but you can definitely just smell it. And i checked my injectors they were all above required spec. My o2 is maybe 3 years old, i dont run a egr valve on the car, i know that could cause it i just have it unhooked right now, the SES light comes on only if your driving on a highway at constant speed of 55 MPH or above for a long time, but it doesnt affect anything while driving the car. It actually ran better without when i first got it due to egr solenoid going bad. Learned something new today thanks guys

skibum2100

What is the SES code you get (please not 44)?

Tuned Performance

iTrader: (92)

I' betting 32 !!

StevenB L98/LS1

i havent checked the light in forever, but its never on unless like i said your driving a long period of time at a higher rate of speed. Then you turn the car off and turn it back on the light stays off just doing regular town driving. But i believe when i checked the SES light it was 32. There was a crack on the egr solenoid so there wasnt enough vacuum pressure running from the solenoid. So i removed it.