After the hot days of the summer, using the AC and other electronics in the S2000, I got a bit perturbed about the Idle dip when the AC compressor kicks on.

old Idle was at 1000 rpm and the AC would make it dip to 600 rpm, sometimes stumble and one time even stalled on me!

I re-adjusted the TPS to just over the idle threshold and had to adjust the idle stop screw to bring down the RPM to about 1400RPM. I also took up some slack in the throttle cable and am now enjoying a VERY responsive car!

It seems that the ECU reads a closed Throttle plate and cuts back its brainpower (prolly for the LEV status) and so if your stopped at a light or something you may get a little bog off the line during a regular 'launch' I had gotten in the habbit of pre-revving the engine to get the ECU out of that 'suspended' state but now its not needed. The AC will bring the RPM down to a steady 1000 and the engine will no longer bog.

Its almost a different car - NOTICE I do have the bored TB so there might be an issue with that originally but I think I remember the bog a bit with the OEM TB.

 

My idle speed does not change at all with the AC on. I thought all modern cars had an AC idle up?

 

You know I could swear it used to dip and then come back up to 1000 but latley it hasnt. Seems that most of my electrical stuff affects Idle speed IE: brake lights/headlight/ and even the AC fan w/ the compressor on.

My S is modded enough to screw up the idle anyway

Iridium plugs gapped at .045/Proflow TB@70mm/Fuel pressure @ 44psi/Insulated intake/K&N filter/Neuspeed EX/Other cool stuff but its a secret

 

What are your readings on your TPS now?

 

Please tell us how you adjusted the TPS. A lot of people have the bogging/hesitation problems and need a fix.

 

I found the old threads on how to adjust it, but the stock TB does not appear to be adjustable. If those are allen bolts holding it, then the factory must have filled the allen head with solder and put white paint on top of it. They are not coming out!

 

[QUOTE]Originally posted by rstark
[B]I found the old threads on how to adjust it, but the stock TB does not appear to be adjustable.

 

No, I'm not going to mess with it. I was just hoping for a quick solution to my hesitation problems.

 

Ill get the numbers, and even give a measurement of how much the butterfly is open. Ill have to do it tomorrow afternoon.

I do remember the stock TB having non-user adjustable bolts but mine being the ProFlow re-bore just have regular allens.

You can still adjust the Idle stop screw with I think a 2.5mm allen and a 7mm open end wrench. I gave mine about 1/8 turn.

If you dont mind modifying your car and letting it idle at 1500 RPM then I think its worth it.

 

Not sure if I want to idle that high, but heck, if it cures the problem, I might think about it. BTW, I measured the voltage of my TPS and with the engine off, it read 4.80V DC.