always adjusting the TPS and IAC??

[EyeTalk2Trees]

My IAC needs adjusting every week or so. I will get it tuned with T-link to idle just perfect. Then it will slowly get worse untill its idling up and down, up and down... Does this mean my TPS could be going out? I added new injectors and entire Valvetrain(planned upgrade) thought it might clear it up but it only marginally got better.

Can a TPS go bad in just part or run poorly without going out completely? I talked to so Non-TR mechanics(never worked on a TR) and they said sometimes they can get dirty and cause "electric noise" when it changes as the throttle is opend and closed. Has anyone else had this happened or heard of this?

THanks

 

[FJM568]

Check close for vacuum leaks...You must have a leak that gets progressively worse...I've had the gasket between the turbo and the TB somehow get cracked and partially sucked into the turbo and it drove me nuts trying to find the vacuum leak...Take your intake tube off of the TB and open the throttle all the way and shine a light into the opening and see if you can see any gasket material hanging down...If not, then with the motor running, try to spray the turbo/TB mounting flange with something to see if your idle changes...While you're at it, see if you have any leaks at the turbo to manifold adaptor o-rings...

Hope this helps...

 

[EyeTalk2Trees]

I was thinking along the same lines when i re-did most of the valve train. So i cleaned and checked over the throttle body, replaced every vacuum hose, and even the turbo o-rings. I know i fixed at least 2 leaks in the process adn the TPS problem is much better. It will do this and hten sometimes it will settle into a steady idle. I guess its a leak somewhere, I'll just have to keep looking. just running out of places to look

 

[FJM568]

Have you ever had the intake off??? You may not have gotten it sealed back up all the way...If you have had it off, did you have the heads milled or anything like that??? Has the motor been overheated before you took the intake off, etc??? Intake may be warped some from overheating(if it has)...Just throwing out some other troubleshooting ideas...

 

[EyeTalk2Trees]

thats a good idea, the intakes can warp? I'd never have thought of that, it did get really hot a few times around 260F but it never quite running. I did have the intake off and I port matched it to the gasket. I get better vacuum than I did before so I don't think its a huge leak. I'll spray around the intake too checking for leaks.
thanks

 

[FJM568]

Are you getting alot of blowby or oil dripping from the valve cover breather(if you have one)??? If so, and the intake is warped, it may be leaking into the lifter valley and you may not notice any leaks on the outside of the motor...Check it out to try to find a leak on the outside before you rip the motor apart again...Take the intake to a machine shop and have them check the flanges for warpage if you can't find any leaks anywhere else...

And yes, 260F is really hot...It *may* have warped it, it may not have...You won't know until you have it checked...Good luck, and post your findings...But don't tear into the motor unless you have ruled everything else out...

Hope this helps...