[SA] VP V6 Commodore Executive - Surging issue.

[spirto]

Hi everyone, this will be my first post for engine mechanical issues.

Engine : V6
KM's Travelled : approx 180,000km
Problem: Surging at idle - sounding like one piston faulty.

Items Changed/ Checked.

Changed :
All 6 Injectors
Oxygen Sensor
Coil Pack

Checked:
Ignition Leads - with multimeter all ok.
Fuel Pressure regulator - Vaccum hose removed, no fuel shown in pipe.
ECU (COMPUTER) - swapped with a perfect running VP Calais no difference to surging problem.
Fuel Pump - Checked
Map Sensor - Checked
Vaccuum Lines all checked and are connected.
Exhaust emmisions - inside the exhaust it is showing perfect combustion, eg. no carbonisation, and is running efficient.

Items not checked - YET
Throttle body position sensor
Idle Bypass Vacuum Modle.


[B]ProblemB]
When the engine is idling the revs go up and down kinda like a injector or spark plug being faulty, but when you check at the exhaust pipe there is no missing at all and is "whistling" like a new engine.

Findings:
Injectors - When I disconnect each wire on each of them - A visual decrease in revs is shown.
Injectors - I can change the wire connection for 1 & 3 and 4 & 6 eg. put 1 on 3 and 3 on 1 and same for the other two, but I have found that it makes no difference - Question ? How do you tell which order is correct as the connectors have random numbers nothing showing eg. 1 for 1. etc.
Main Vaccuum from inlet manifold to brake booster when disconnected engine revs increase dramaticly, (which is normal) but when I place my finger over the vacumm outlet on the manifold the engine almost dies completely - why?

Solution?
Guys/Gals any suggestions on where to try next? I wish to sell this car in the next week or so but when it is idling like this can makes the sale hard. I am willing to buy a carton of beers to the person who finds the solution . (Shrugs shoulders - HELP).

Thanks
Spirto.

[spirto]

any help people?

[brockee]

are the injectors seated properly no o rings fallen off or in the holes check!!!! also could be throttle pos sensor

[spirto]

Hi there,

All injectors are seated correctly and have all the o'rings. I am checking the throttle position sensor this week as well as the Idle Vacuum Module.

Will let everyone know my findings when I know... but this is making me tear my hair out LOL.

Spirto

[brockee]

hey mate got it sorted yet

[admk69]

brockee what was wrong?

[VPRob]

I was going to throw in is the AC on? If it's borderline for pressure it will cut in and out and cause a pulse or surge when idling and under load. If it's fixed what was it?
cheers

[spirto]

Hi guys, sorry hadn't subscribed to my thread, didn't find the solution, thanks for the suggestions. I ended up increasing the revs, replaced the oxy sensor,.even the computer with no luck, car was for sale, ended up being sold as it was. Close thread.