2003 S2k - fluctuating idle

[jbaker]

2003 AP1 S2000
Hondata Krpo III
KManager 3.2.2.0

I have spent an excessive amount of time trying to figure out my fluctuating idle with no progress. It starts up fine then after warmed up, it starts resonating. I have it set 850 rpms and when it fluctuates, it bounces between 500-1200 rpms till it stalls. Every red light...I'm constantly restarting the engine.

I have attached the most recent calibration and datalog. Towards the end of the datalog, you can see the fluctuations. I flip the heater on and it stops the fluctuations. I'm stumped. The current calibration is making crap for power too. Mechanically, I have cleaned the throttle body IAC and vacuumed checked the coolant system. I'm working with a good tuner and this has him scratching his head. I have had mixed advice from several people at our first SCCA solo event here in Birmingham and hopefully someone here can figure this thing out.

Can someone take a look and perhaps find something overlooked?

I have verified the TPS. Here is a list of the mods for parameters input (they have been entered):

1. Spark Plugs, gapped at ~0.25" - NGK, Resistor Type, BKR7E-11, Stock No. 5791
2. 5 bar MAP sensor - SSI Technologies Inc., P51-50A-B-P0-4.5V, S/N 050771162
3. Tial Wastegate - Tial Sport, SN05060654
4. RC750 cc fuel injectors - impedence test confirmed 12.2 ohms
5. GM boost solenoid
6. Log manifold
7. 70mm BDL throttle body
8. Precision 6152 Turbo
9. 3mm head gasket

Thanks!

[Spunkster]

Your TPS never drops below 5% except for a split second in a few places. I would start there.

[jbaker]

Your TPS never drops below 5% except for a split second in a few places. I would start there.

Thanks, I'll look it over again.

[jbaker]

Yeah the TPS wasn't consistent when I checked it again. I cleaned the throttle body and cycled it a few times, got consistent readings this time. I also cleaned the IAC while I was at it. I reset it and seems fine at a warm idle now. I'll have to drive it and see what happens in morning traffic.

I'll keep my eye on it.

Thanks!