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You know, everyone always says not to mess with the TPS but I have to say that I disagree, strongly.

When I did my swap, the new engine didn't idle very well so I ended up adjusting my TPS and it helped a lot. Then when MVP performance tuning (Matt, Vikash, Phil) installed my WRX tmic we swapped in a new tb that we cut and again I was having pretty bad idle issues. The idle was really bad at first and V suggested that I not mess with the TPS again and so we tried to use the CC linkage to adjust idle. That seemed to help a tiny bit for about a week, then my idle went to hell again. My idle was good if I ran the AC but without it the car would stumble pretty bad and sometimes stall when I went off throttle, like at a stop. So anyways, yesterday I went with my gut and went out and adjusted my TPS and now the car idles perfect and when I go off throttle it runs smooth and I have no stumbling issues whate so ever now!

So here is my reasoning. The TPS is set from the factory right? And that is why everyone says not to adjust it right? Well when you mod your car, especially a TMIC or FMIC, you are changing the flow characteristics of the engine and so a TPS adjustment makes perfect sense to me. Let go of your fear, if you have idle issues or stumbling, you don't have to live with it anymore. Adjust the TPS and you'll be happy you did! Cheers!

I'm not sure about everyone else, but I'd say, mess with your TPS. It's the throttle stop screw that you shouldn't mess with.

The TPS should be adjusted by following the procedure in the scan below.

http://www.main.experiencetherave.com:8 ... sting3.jpg

Oh really? I thought everyone was always saying not to mess with the TPS either because it was factory calibrated or whatever. But ya, if you're modded, it's a must I'd say.

Yeah, it was the throttle stop that I was apprehensive about screwing with...

The FSM gives a procedure for calibrating the TPS. It's actually just the idle switch that's being calibrated.

How did you do the adjustment?

So rotating the black sensor calibrates it?

Well, rotating it the right amount, yes.

vrg3 wrote:Yeah, it was the throttle stop that I was apprehensive about screwing with...

Hmmm, that's strange, that is not how I remember it at all. I remember saying that I wanted to adjust the TPS and you said it was factory calibrated and that you thought it was a bad idea. I even mentioned that I had done it after the swap and you said that was ok but that you still thought it better not to mess with it. We then tried to adjust the throttle stop and couldn't because the screw wouldn't budge even after being PB'd and I was worried about snapping it, we even tried pliers remember? You then suggested adjusting it with the cruise control linkage, which we did. That helped a little for about a week, then the problem came back.

How did you do the adjustment?

I just loosened it and set it to where I had the last time after the swap. I just eyeballed it and then turned the car back on and it ran sooooo much better. If I messed with it some more I might even be able to get it a little better but it's really good now, so I'll probably just leave it.

I think you could adjust it with the engine running and tune by ear too but the PCV hose and the TPS connector would kind of be in the way to tighten it back down that way. You could set it, then turn the car off, unhook the PCV hose and tps connector, then tighten it back down though.

How does the FSM say to do it?

Hmm... I may have to tinker a little with mine. Last week I got thrown an 'Improper Idle Switch Signal' (42), after I parked went in the store and came back out the light was out and I didn't have any more trouble until today when it threw a TPS code. The FSM says to use feeler gauges and was why I didn't tinker with it initially when I swapped my motor but it sounds like that's what I may need to do.

Thanks Matt for being a first.

skid542 wrote:Hmm... I may have to tinker a little with mine. Last week I got thrown an 'Improper Idle Switch Signal' (42), after I parked went in the store and came back out the light was out and I didn't have any more trouble until today when it threw a TPS code.

That means yours is probably bad, not misadjusted. Grab a JY throttle body and slap it on there. That should make the code go away.

Hehe, well it may be bad but I've had a little bit of a trouble with my wiring since the swap and before I decide that my TPS is bad I want to try adjusting it first and I still haven't ruled out the ECU being bad since I still have to manually turn on my radiator fans. I should also mention it has a little bit of a hard time in the low RPM's on cold days until it's warm and sometimes kicks just a little when I let off the gas, yeah I'm still suspisious of the IAC too .

Matt - Hmm. The way I remember it, I didn't want to adjust throttle stop, and suggested that maybe it would figure itself out as the ECU learned. When we got to the track and found that it didn't happen, we tried turning the screw and found we couldn't. So we tightened the cable instead, which as a bonus didn't screw with the stop screw.

But I don't remember talking about the sensor at all. Or maybe I smoked too much crack that weekend.

If your adjustment helped, cool. But, I think you still may as well try the FSM procedure if you have some feeler gauges:

http://www.main.experiencetherave.com:8 ... sting3.jpg

You can read "No. 1 and No. 2 conducting" as "Select Monitor reports ID as on in mode FA1."

Lee - I get the same thing sometimes. I think my TPS connector's contacts are just a little loose. I unplug and replug the TPS connector and all is well... for a while. I've been meaning to pull the contacts out of the harness connector and bend them a little to make them fit more snugly.

vrg3 wrote:
But I don't remember talking about the sensor at all. Or maybe I smoked too much crack that weekend.

Weeeellll, you did smoke an ungodly amount of rock that weekend. I mean, I'd never seen anyone smoke crack out of a 3' glass tube before!

I'm an impressive guy. =)

Hehe, well, you literally were smokin' rocks that weekend....it's just that they were of the gravel variety.

hehhehe... Truth.