My Car WRX MY 05 (300) on PPP. It has an issue of some hesitation on acceleration from low revs,
( which has been particularly present ever since replacement of the short Std WRX engine block +005 overbored.)
I also had a very slight hesitation on the previous engine, that was mapped by JGM 2012, Simon did a bit to compensate that on Road tune but it was never perfect on a full throttle application from low revs.

As I had done some porting work to the cylinder heads, I recently had a remap done at SRR and on TD05 16G have 310 BHP.
But the new mapping has not cured the hesitation in lower revs range ( These occur on any strong throttle applications from idle till boost builds ). When it occurs it feels as if the ignition timing is wrong, almost like a fuel cut or as if a boost leak had occured (except its all tight ).

Exhaust leaks are fixed, Boost leak checks done and I have already replaced the MAF sensor. all to no effect.
The TP sensor looks to be original has not been replaced in the 6 years I have owned the car.
So I am now considering replacement of the TPS, ( which I think is PN # 22633-AA210 )

As these are expensive I'd like a confirmation if this is the right part # to order and a tip on best supplier.

As a side point , I do find that my throttle pedal has always been very sensitive,
it only needs to be given a slight movement , and that gives rise to a large re-action
this makes fine speed control a little difficult , in particular when driving over a few bumps.
Currently I can reach WOT well before the pedal ever reaches the floor.

Id be interested if the TPS can be mapped to be less sensitive ?

Also any other suggestions on what to check for , help to prevent this annoying hesitiation.

Thanks Ralph

 

This may be a stupid question, but didn't the 2005 wrx have a cable operated throttle? I'm sure my 2005 wrx did.
I thought the TPS module only came in on the 2.5 and JDM models?

 

Cable operated still have TPS to tell the ecu at what position the throttle is.

 

The Throttle position sensor sits on the end of the butterfly shaft, The throttle cable actuation cam sits on the other end.
I think they are 0-5 Volt but I need confirmation of the PN #

I could conceive that if the potentiometer arm had over the years , scored its way into the resistor material , that you would get a flat spot as no voltage would be recorded to the ECU. I have had exactly this Problem on an Audi 100 but after 200k miles , and the dam things are now unobtainable. I ended up butchering one from a Merc 190 and putting it in the Audi housing. see photo's of the Audi issue.

I really hope I can get the right one, and that it cures this hestitation as I suspect it can be very bad for mixture / AFR if others have ideas Im all ears. My MY05 WRX car has about 120 K miles on the clock so it could well be worn.

 

The TPS and the tumbler sensors are the same, I have a few TPS`s I will have a look what PN`s they are.