high idle after changing throttle body

[pac_jb]

Hi,

I just replaced my throttle body, now my idling is high around 1300rpm, could this be because of faulthy tps sensor?

 

[vr2turbo]

What car/engine? For some you can tune the idling speed using air feed screw.....

 

[pac_jb]

Hi, its a evo 3 engine, i just replace the throttle body to s90, the air feed screw is tighten to the max. But idling is still high around 1300rpm, already drive the car for one week, still not going down..could it be because of the tps sensor

 

[vr2turbo]

Something is wrong as the air screw cannot be tighten to the max. Maybe there is a leak somewhere in your vacuum hoses

 

[pac_jb]

No vacumm leaks bro, but the same thing happened last time when i cleaned the previous throttle body

 

[vr2turbo]

No vacumm leaks bro, but the same thing happened last time when i cleaned the previous throttle body

So, the previous time it de-tune itself?

 

[pac_jb]

Previous time, after months of driving the idling went down too low, below 500rpm, then have adjust back, thatz y suspect something wrong with tps

 

[sanekit]

have you check your butterfly? sometimes got vacuum leak when you service the TB. need to add some sealant on the side behind the butterfly.

if you suspect TPS, just check the voltage for it using multimeter. normally if TPS problem, check engine light will turn on and give TPS Sensor error code. my tps was loose last time due to the socket clip broken and CEL comes on and car feels like dying.

 

[pac_jb]

No bro , this is brand new throttle body, high idle after installing it, and same thing happened when i cleaned the old throttle body last time, maybe IAC ?

 

[vr2turbo]

IAC usually on load, right? Try turning air con on and off to see any difference

 

[sanekit]

No bro , this is brand new throttle body, high idle after installing it, and same thing happened when i cleaned the old throttle body last time, maybe IAC ?

Does your TB bore same size as your intake manifold? if not, there might be a leak on the gasket connection there. some photos would help.

 

[pac_jb]

I installed 70mm s90 and rebore the manifolder

 

[sanekit]

I installed 70mm s90 and rebore the manifolder

rebore manifold means you took out the intake manifold from the head. i still feel that it's a vacuum leak. need to open again and check the gasket.