Many people might have already heard of my situations... the car jerks at 1600 to 1750rpm range and sometimes at 2100rpm at light throttle while cruising... I finally got the cipher kit yesterday and got a chance to do some logs....

I found that the cam timing at the left bank isn't as smooth as the right hand bank, but it never shows that the cam angle drops to "0" as suggested by the motec computer though... and you can be able to see the engine rpm goes up and down withint those rpm ranges too...

Do I have a bad cam sensor or a bad VTC??? or I simply just need more fine tunings?? The solenoid signals are all quite similar at both banks though... please help!

Thanx in advance!

Here are those files (they are also excel files): (right click and save)

http://www.sil-chem.com/rlchen/cipher/Cam_Surge1.csv

http://www.sil-chem.com/rlchen/cipher/Engine_Surge1.csv

http://www.sil-chem.com/rlchen/ciphe..._Surge_1-1.csv

http://www.sil-chem.com/rlchen/cipher/Engine_Surge2.csv

http://www.sil-chem.com/rlchen/cipher/Engine_Surge5.csv

cheers,

richie

 

Isn't the Motec connect to the same wire as the cars ECU that reads the cams angle? If it is and the Cipher reads different than the Motec, then the problem I would say is improper signal to the Motec (bad connection) or a malfunction in the Motec.

 

Hi Richie,

Wow the diagnostic power and potential of the Cipher is now seeing light. I never thought of being able to use it for this. Can you explain more in depth how the Motec is wired into the cam sensors and/or timing control?

 

dave,

thanks for that... I am not too sure how they are connected though... but here is the wiring loom used on my car....

I have 2 auxiliary output functions from motec for Cam Controls... and 1 Digital input function for the Cam Position.... and both Cam Controls(output) are sharing 1 cam timing table (Left bank)... and that's all I know...

thanx!!

cheers,

richie

 

[QUOTE=Z350Lover]Many people might have already heard of my situations... the car jerks at 1600 to 1750rpm range and sometimes at 2100rpm at light throttle while cruising... I finally got the cipher kit yesterday and got a chance to do some logs....

I found that the cam timing at the left bank isn't as smooth as the right hand bank, but it never shows that the cam angle drops to "0" as suggested by the motec computer though... and you can be able to see the engine rpm goes up and down withint those rpm ranges too...

Do I have a bad cam sensor or a bad VTC??? or I simply just need more fine tunings?? The solenoid signals are all quite similar at both banks though... please help!

Thanx in advance!

richie

Were the logs you have posted of the surge in revs the result of holding the throttle pedal at a set position ?
If so, you can see whenever the revs drop there is a corrosponding drop in cam angle advance.
Now the $64 question is: Is the VTC controller responding by retarding the cams because the revs are falling for another reason, or are the revs falling in response to the retarded cams.
I beleive it to be the latter which means that there is a malfunction in the MoTeC VTC opperation.

 

Peter,

The throttles were not exactly at the same positions though.... and the revs weren't falling due to the cam regtarding though.... and I spoke to Simon about it, he also reckons that it is the motec "software" that is a bit doggy at the cam control and they just never listen to all the opinions from all the tuners on how to adjust the cam controls... The cam timing functions are motec aren't perfect yet according to him and that's the problem there...

Also he reckons that cipher is reading the "cam timing" that the factory ECU wants to do, but motec is not doing that exactly (since we steal the cam timing signals from the ECU for motec), therefore the cam timings readings don't reflect what motec is doing actually... and the surges happen when the motec cam timing is trying to smooth out its own operation at a constant throttle input, therefore the "sign wave" cam timing occurs... does that make sense at all????

cheers,

richie