VY2 v6 rough idle

[David Rieck]

Morning , My vy has a rough idle and misses through the rev range . Had it diagnosed at a local mechanic. He checked for vacuum leaks , and injector pulse and a compression test . Found #1 with bent prongs on the injector . He repaired that. But Found an issue with the injector . So took the car home and fitted a full set of recon injectors but still no good . All so put in a new fuel and air filters . New plugs and leads. Swapped out the MAF, Cam Sensor , coil packs and DFI module . Checked voltage to #1 injector around 7 volts .The magnet is still on the cam gear . The injector sounds like its firing when I listen with a screw driver on it . Also the plug in #1 gets carbon build up like its running cooler than the rest . Any Ideas guys this is doing my head in . The engine light isn't coming up . Can it throw up codes with out that happening.

 

[PlenumBiscuit]

Cleaned out all the gunk in yhe throttle body

Iac ans tps?

 

[David Rieck]

yep first thing i done , what is Iac and Tps

 

[PlenumBiscuit]

The 2 sensors on the tb...

Iac - idle air controller

Tps - throttle position sensor

The first day i got my vy i bought brand new vacumm hoses from sprints cut n clamp and perfect your vaccum.

Even if he checked for leaks did he do by eye or with equipment

 

[David Rieck]

Unsure how he checked for leaks . Have VU ute here will swap out the sensors on the Throttle Body

 

[PlenumBiscuit]

hoses are cheaper than french fries at Sprint Autos

theres about 3 different sizes required. just park in there car park and do one size at a time. its a good feeling knowing the vaccum lines are mint sealed and brand new and done with your bare hands with zero doubts

 

[David Rieck]

No sprint Autos up here in Qld . Swapped out the sensors still no joy

 

[lowandslow]

Did you do any work to it or touch anything leading upto to this problem starting?

 

[PlenumBiscuit]

ok gotta go deeper. i would buy some contact cleaner and spray clean every electric sensor plug you can find, such as the plugs on the injectors, on the throttle, just ensure absolutely everywhere theres no gunk on the circuits. cleanup your earth/ground points too theres one at the front of heater bolt, that star washer wire thing on one at the back passenger side of engine.

on the VS commodore you had to add more earth to the ecotec, ive done this to my vy too, more earth wont hurt, will get u a pic of what i mean

check your plenum lid in down tight no leaks

youve got new coils but do u know how to test them at home?

also when car is running, take 1 injector plug off at at time, if nothing changes to the idle speed, then the injector is faulty

 

[David Rieck]

No , no work to it prior to this problem .

Removing #1 injector cable the idle dosent change , There already a full set of recon injectors . Will check all the earths and so on . A pic would be nice thanks . No I dont know how to test them at home.

Could it be the ECU ??