Hello,

Just finished tuning my friends car using Crome free and Freelog. Tuning was ok...after that we noticed the rpm could not hold 2500 rpm at idle as it suddenly bounce below 1k rpm and back to 2.5k rpm and back to below 1k and resume back at stock idle around 1.2k

Specs of the car is...

B20 block resleeved
86mm supertech piston
Skunk2 Pro 3 camshafts
Edelbrock copy IM
S90 70mm TB
Chipped P28 with Crome and Freelog
Stock ignition with NGK blue cable plug
NGK spark plug (gapped)

Is it the cause of extreme cam profile as we need to maintain around 3-3.5k rpm for launching purposes.

Any help would be appreciated. Thanks...

 

what makes you think its tps related? check volts of signal output to see if tps holds acurate volts or jumps around while at a stead throtle possition. do you have a launch control enabled in the software? try adjusting the fuel cut off peramiters or timing cut values. does it have the same symptons if the car is rolling and holding 3k rpm?

 

Well checked the TPS...was at 0.30 - 0.40v at closed position and around 4.5v at wide open throttle...this was tested with ignition ON and engine off...
The car is fine at rolling and could maintain partial throttle at 3k rpm...and yes launch control is enabled but set to 10k rpm cause the car launch manually at drag...

Will try disabling launch control and checking timing/fuel cut parameters (dont know if Crome has it)...thanks for the suggestion odz-fab...

 

Sounds like you dont have the right injector dead times for the injectors that your using. Switch to better engine management such as Hondata or Neptune, the car will idle alot better.

 

Hmm...will try and suggest that to my friend...looking forward on Demon+Neptune...
Will start to troubleshoot again tomorrow and hoping to solve it...will update on this...

FYI...current injectors are DSM 390cc from Mitsu GSR 1.8T (I think its rather small for his setup)

 

Weird...started the car today after 1 1/2 days of no ignition cranked and the idle was ok and the car could hold 2.5k rpm with no issues...

Is it possible that the TPS was wet (coz I read somewhere it could cause the issue)