HELPP!!!! vt v6 passenger side cylinders all running rich tried the usuals....

[mickymodge4]

ive put a post here not long ago thinking ikt was the o2 sensors but new o2 sensors hasnt fixed the problem. the car is running rough on petrol not gas only when it is warm when it is cold it runs fine once she warms up she starts missin under slight throttle not wot and at idle like a pig almost sounds like valve guides worn from the exhaust note. i dont have a scan tool however the lhs bank 1,3 and 5 are all running rich the injectors are plugs new fuel filter tps and iac, leads are all tested ok air flow meter and temp sensor have both tested ok as well...compression is all good as well. ive taken off the pass side rocker cover and rockers to check valves and there is a bit of play in them if it is the valve guides why is it not running like this on gas????

[lout]

make sure your left O2 sensor is in fact wired into left input and not right.
this usually occurs when changing firing order on fords. but I suppose it's possible to mix O2 sensor plugs on a holden.
when cold the car uses the ECU trims when warm uses O2 sensors.
If wired wrong will keep increasing left bank fuel trying to correct lean right bank

[mickymodge4]

hey mata thx for reply from yep they are they can only go one way on holdens the left o2 sensor from cant really reach to the rhs connector and vice versa thanks anyway ill just keep rackn my brains and losn more hair!!!!!!

[codeunknown]

is that 1 side is running rich or one side plugs from there coil pack is not thumping them with the required zap power ?

?

[pablo]

Since you have tried all the obvious, have you swapped over the O2 sensors (left to right & right to left)to do a double check of their operation.

[mickymodge4]

codeunknown yes thought of that so i swapped over coils and still its the left bank that is down even when i take off the injector wiring all the left bank doesnt really make any rpm diff but the right side 2,4 &6 does good point tho and pablo great idea will try it out asap!!!! thanks maybe a dodgy NEW sensor!!!

[mickymodge4]

pablo tried your trick and didnt work still problematic cylinders 1,3 and 5 runnin rich!!!!!

[bozz73]

There are relatively cheap multi-meters that can measure duty cycle on your injectors.
Compare L+R bank, this will make sure the 1-3-5 is running rich (or not)...
Plugs are also a relatively good indicator for comparing.

[lout]

throw another set of spark plugs at her. I have just been tracking down a miss 500k's after service on a pontiac, 3 of the NGK plugs I used decided they didn't want to spark.

[mickymodge4]

bozz i have 2 muklti meters at home how do i know if these can do the job???? what is duty cycle??? and lout this problem was there before i put the new ngks in them but will try swappin them over and see what have i got to lose?????

[mickymodge4]

also whacked the scan tool on it at a workshop found lh short term fuel trim -28%!!!!! rh side was -18% i think

[mickymodge4]

also whacked the scan tool on it at a workshop found lh short term fuel trim -28%!!!!! rh side was -18% i think

psi on my guage???? also why didnt this play up on gas as well??? coz gas dont burn as hard????PROBLEM SOLVED!!!!! after so many sleepless nights ive solved the problem...burnt out exhaust valve on number 3 cylinder... what was throwing me off was two factors both compression tests i did came back within specifications 185-200 psi in each cylinder. decided to do a leak down test before rippin apart the heads (wanted to be 100% certain) found cylinder 3 leaking air whem pumped up...could hear hissing coming from near spark plug hole thus removed ex manifold to hear escaping air gettn past the exhaust valve sprayed soapy water down the exhaust port and BINGO!!!!! why wasnt this leak being picked up on my compression test??? esp when on comp tests the pressure was up at 200 psi and on the leak down test it was only at 120