flutuating rpm at crusing

level z · Post by **level z** » Sat May 19, 2007 3:53 am

Hi Guys,
Currently driving a dc5r (jdm K20A). Mod to car Toda A2 and K-pro hondata. Intake HKS mega flow. Header and exhaust stock. Cat not removed.

I experience the following problem and hope to get some help here. Thanks in advance.

1) RPM drops to 500/600 after clutch in. Will try the retard on the advance cam setting.

2) Once in a while i experience this.
a) Car starts to jerk during driving even though fuel pedal is held down constant. When this happen i usually clutch in and rev the rpm a couple of time. It does help but it does come back as and when it wants. (Suspect TPS not giving correct reading to ECU. TPS Sticky ?? need to replace TPS ?)

3) During start up (hot or cold is the same symtom), rpm hangs at 500/600 rpm. Black smoke (can smell unburn petrol) at the exhaust. Reving the engine does not help. (Datalog before saw MAP reads 122 KPA). To resolve this problem when it happens, i need to reload the tunned map. It does happen consistently once every 2 weeks or some.
(PS I tired swopping with a working MAP sensor but problem still persist. Only on uploading tuned map then the problem is resolved).

regards
Level Z

BTW my car is running NA. Have also cleaned the Idle valve. Fuel octane 98. Stays in a tropic country.

Post by **Spunkster** » Mon May 21, 2007 9:37 am

http://www.hondata.net/forum/viewtopic.php?t=3629

level z · Post by **level z** » Thu Jun 14, 2007 7:43 pm

My car config as mentioned. Attached is my calibration and the datalog that shows the jerking. In the 20 seconds frame. I notice the MAP reading went 122 kpa though my car is NA. Any advice given is appreciated.

regards
level z

Post by **Spunkster** » Fri Jun 15, 2007 1:53 pm

Make sure you have not swapped the map and tps sensor plugs.

level z · Post by **level z** » Fri Jun 15, 2007 3:48 pm

Spunkster wrote:Make sure you have not swapped the map and tps sensor plugs.

No. I did not swapped the map and tps sensor plug. the map and tps sensor is stock. Do you see anything out of the ordinary in the calibration ? I have checked the voltage reading of the MAP sensor before engine start and at idle ... reading is normal. thanks,

Post by **Spunkster** » Fri Jun 15, 2007 4:22 pm

The only way you would be able to read boost on a NA vehicle is if you swapped the plugs that plug into the MAP and TPS sensors. This is easy to do since they are in nearly the same location and have the same plugs.

level z · Post by **level z** » Fri Jun 15, 2007 7:45 pm

My TPS reading from K manager is correct. I have checked the wires (green/red) from the MAP connector and the voltage reading is as accordingly to the guide given in Kmanager literature. Could it be cos i am tapping the VSS signal (from the ecu to be read on the rsm) and feedback voltage from the RSM giving me the problem. This is my initial suspect. I have since removed the rsm wire from the VSS wire at the ecu conenctor (white/green) So far the car is ok. Thanks.

PS The green/red wire at connector plug into map sensor correspond to the green/red wire in the ecu harness. Conenctor A 31p wire number 19. Just to stress a point from the datalog i conclude the High MAP reading caused the jerk.