Hey guys so I just got done doing a fast 92 install with a speed engineering 92mm throttle body, still using stock maf and slp lid. Went to start the car and it won’t start and idle and cel came on for p0122 throttle position sensor, so I switched out the tps that came with the throttle body to my old one and still the same thing is happening and cel comes back for the same code. Any ideas on what to look for? Or anything I might need to do adjust on the throttle body?

 

Anyone have any ideas?

 

Are you certain that you don't have a vacuum leak? You may not have the throttle blade cracked open enough to get it to idle.

 

I checked over every vacuum line, torqued all bolts in sequence so doubtful it’s a vacuum leak, The cel comes up as p0122 for the tps sensor. I saw that some people had to reclock their tps sensors on aftermarket tb but not sure if that’s related to what I have going on

 

It may be your throttle body blade is not opened up enough and if it cannot getting enough air through then it will stall. Also is your MAF hooked up?

 

Your most likely going to need a new tune!

 

Yes it is, it’s still my stock maf

 

I know this but the car should still start up and run at least, and the fact it’s giving me this p0122 for the tps is confusing me.

 

Anyone else have any ideas?

 

What is your key on volts for TPS?

 

I will check when I get home from work, I know with key on throttle % was 0 and pushing pedal down went up to 100 just fine.

 

I figured that was likely the case. There is a certain voltage range it will need to be in to properly zero. If it's a 102, i usually start with 0.67 volts, then do the rezero procedure (unplug tps, key on engine off one minute, key off, plug in), and then use the IAC counts to adjust from there

 

Mine is a 92mm where should I start with that?

 

So I took a voltmeter to the blue wire on tps sensor, with car on not running if I move the blade to wot I get 3.94v when i close the blade the voltage is all over the place but if u slowly crack it I can get it to .499-.5v so I’m assuming I can set the idle screw so it stays within that value for idle? And does the wot voltage seem ok at 3.94? When I look at throttle percentage on my hand held scanner it reads as 100% throttle but 3.94 seems low

 

I was assuming you had hpt or efi live. You can just track tps signal voltage in the scanner.

On the earlier ECU, there were some you could get to reset as high as 0.76 volts. Others will not reset above 0.69 volts. It is kind of hard to predict. So I start at 0.67 volts knowing all of them will reset. Then if it still runs with high counts I'll drill into the blade.

Usually 4.5 is necessary for wot

 

So i hooked up the stock throttle and measured on there that idle is .750v and wot is 4.40v so should I adjust the new throttle body to those measurements? I’m assuming since my wot maxed at 3.94 I will have to slot the tps sensor to get it within spec?

 

Was this intake purchased used or new?

 

Brand new fast 92, I was able to get the car started by adjusting idle screw on throttle body, got it to idle ok but when you shut the car off and turn it back on it always shoots up to 2000rpm then idle backs down slowly, and if you blip the throttle it will stay at high idle and go back down slowly, we had hp tuners hooked up and the iac for whatever reason was reading 0 when car was fully warmed up. Then started reading around 35-45

 

Sounds like you adjusted the blade a little too much. Idle hang could be a vacuum leak. Did the intake come with Allen head screws for you to replace the valley cover bolts with?

 

Yes the bolts were replaced with the button head style