ousi

Have been reading the forum for a while now and enjoyed my ride in track days

However, my S started to idle rough and throws CEL light with the very "common" TPS code.
I ordered the TPS from OmniPower, replaced it, clear CEL code and it's still idling rough + it will stall at stop light.

I do downshifts, no coasting and whenever I release the clutch at anywhere below 1.2k rpm it just stalls.

Right now I'm thinking about MAP sensors or O2 Sensors. Cold idling is around 400rpm less than normal. Hot idling will go as low as 500 rpm and back to 700rpm and she's just about to stall...

Any idea? Could someone please borrow me a MAP sensor for diagnostic?

Thanks,
Frederick

HungryHippppo

I'm also researching a similar issue, as I get a slight bog at idle sometimes...

Have you done any recent maintenance or installations on the car?

With your new TPS installed, I would clear the TPS error code, unhook the battery for 10mins and reconnect, start car and idle for 10mins. Does it still idle rough? The below links about the MAP sensor and IACV might be worth checking out.

https://www.s2ki.com/s2000/topic/820...page__hl__iacv

https://www.s2ki.com/s2000/topic/882...#entry20776925

https://www.s2ki.com/s2000/topic/492...ean-iac-valve/

http://forums.s2kca.com/showthread.php?t=19607

ousi

Ok, I'm waiting for the used throttle body arrive.

Will update later.

street_ruler

that may not clear the code. Some times a "hard code" wont disappear with a battery disconnect trick. you might need a code scanner.

when you installed the TPS did you clock it correctly so it reads the correct voltage and WOT and closed? NOTE: i havent replaced one on an s2k but i have on other cars and it needed to be dialed in within reason.

what about an IACV or Idle Air Control Valve? if it comes unscrewed (normally this happens in older cars, the plate & screw just back out over time) it will idle unnaturally low and stall out every chance it gets.

Might be dirty or it might have backed out. theres normally two screws holding on a plate that reveal the valve itself. the bolt/screw inside should be all the way "in"

WestSideBilly

What year car is this on?

The MAP sensor stall/idle issue has been around for a while. Not sure what replacing the whole TB is going to do.

vividracing.com

Double check the orientation of the sensor, and also check your wiring.

ousi

I didn't swap the TB, instead I swapped the TPS in it.
No luck with that either. It was running good and when I was heading back home, cruising at 5th gear at 60mph approaching an exit, the car jerked and Engine light again.
Immediatly called my friend and it's the same code. Cleared it and it came back up instantly.

It might be wiring issue, as the car had a piggy back VAFCII and a Supercharger Piggyback ECU attached before. My friend resoldered the wires back and it was running good till the 6th track day earlier this month.

O2? Or is that an ECU issue? I don't think it's TPS because it's the 3rd one I put in. 2 OEM and 1 OmniPower S2k TPS.

street_ruler

how about you tell us your mods? things like a hacked up wiring harness would have been helpful to know. and the fact that you apparently had two engine management tools and a blower would also be helpful.

ousi

Mods are bolts on (Header, Exhaust). The wiring harness was hacked up at one point and resoldered back. There are only a few left that are "T"-ed to the Apexi RSM module. I just pull out the side-kick panel and had a look. Wires still look fine (with proper insulation). This car was supercharged, and back to normal (that's why the wiring harness was so messed up). Engine was rebuilt before I bought it.

I'm looking into the idling module now. However, the code was TPS, but I have swapped 3 TPS already...

street_ruler

did you dial in the TPS or just bolt it in and go?