VR running rough when warmed up

[PHMaximus]

Hey peeps. my VR V6 has been stored for some time and now when it warms up it runs like a dog, it looses alot of torque and hesitates under acceleration.

Its very consistent too... the car runs like a dream when cold, but as soon as it hits 1/2 temp and the fans come on it all goes bad.

Ive checked for fault codes and nothing comes up?

Since ive fitted a new fuel filter and new spark plugs but everything seems to look ok?
say the leads look good no arching marks and low resistance, the spark seems plenty powerful, the fuel pressure reg it not leaking, the throttle body is clean, I did the CAS about 2 years ago, and i cant seem to find any obvious vacuum leaks?


its really got me stumped... what can cause this and not log a code??? most of the possible causes ive come across generally log a code.

The car is in storage so there is no rush.. ive got all the time to diognoise it, but im just unsure on where to look next, or could I off missed something

 

[PHMaximus]

I found this online... it looks awesome and has some nice diagnosis procedures, but where no start and are there any i can instantly rule out due to lo fault codes?

http://www.snapontools.com.au/__dat...en_Engine_Troubleshooter_Reference_Manual.pdf

 

[Svenok]

I wonder if it could be the O2 sensor, there should be a fault code though

 

[losh1971]

Could be a tps mine failed and never threw a code

 

[PHMaximus]

any ideas on how to test the TPS????? Ive had a look through and i cant find any procedures

 

[losh1971]

AFAIK the only test is a scan. Although mine never through a code but was behaving like yours is. After replacing it a few problems were solved.

 

[Wozza]

You can test the tps with a multi meter cant remember the numbers or which pins...but google it or get the manual
http://www.allcarmanuals.com/models-Holden.html
I doubt its the tps as they tend to play up when hot or cold...if the car running fine when cold but gets cranky when hot, it could be running rich things like dead temp sensor,o2 sensor, faulty/worn injectors ect ect..or electrical brake down when hot... dfi module coil/pack, CAS plug leads..you said it go's bad when the fans cut in..if the battery and or the charging system is marginal and the fans are old, you maybe suffering from brown outs and the ecu gets pissed if the voltage drops below a certain level...

 

[ephect]

I'd point the finger at ur coils or dfi module. Heat increases resistance which you've described the occur only happens when its warmed up. If you have a mate with a vr or vs, swap over the coils to see if that eliminates the issue

 

[PHMaximus]

Before all this started i did fit a new sound system (4ch amp, mono amp, 2x 6", 2x 6/9 and a 10" sub)... but i remember seeing around 14.7v with highbeams on and idling....

I gonna check the earths existing and add another earth strap to the battery just to rule that out and go from there

 

[PHMaximus]

unfortunately. ive got no one to swap parts with my mates all have different cars