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?

 

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

 

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

 

.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/

 

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.

 

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

 

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

 

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

 

I' betting 32 !!

 

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.