Vf calais v 6.0 litre lifter replacement issues

[vf calais]

just had lifters replaced on my car and now car only starts on 4 cylinders, not all 8...
Please assist

 

[lmoengnr]

Start checking harness plugs...

 

[Skylarking]

just had lifters replaced on my car and now car only starts on 4 cylinders, not all 8...
Please assist

Take it back to the place that replaced the lifters

 

[Skylarking]

Start checking harness plugs...

I thought it was a fail safe design where it defaults to all 8 cylinders running under any fault condition

 

[lmoengnr]

I thought it was a fail safe design where it defaults to all 8 cylinders running under any fault condition

Not if half the harness isn't plugged in properly.

 

[Skylarking]

Not if half the harness isn't plugged in properly.

My brain went to AFM issue since it was stated that the engine starts on 4 cylinders..

The VLOM solenoids are normally closed and the engine starts in V8 mode. If a bunch of conditions are met, the ECU must ground the appropriate VLOM solenoids (in sequence) to turn them ON. Turning the VLOM solenoids ON allows oil pressure to be fed to the lifters where they then collapse and the valves stay shut for those cylinders... It's the ECU that commands V4 mode and it doesn't do it in 1st or 2nd hear or below some speed so it should never occur at startup...

If the VLOM solenoids are not plugged into the ECU wiring, they can never be grounded so the engine can never go into V4 mode. If the other engine sensors aren't plugged in, then one would think the engine may have idle/run problems but the ECU would/should never command the VLOM to go into V4 mode at startup. Hence that's why i say the AFM system is a fail safe design.

But if the harness was damaged during lifter instal and the VLOM solenoid wires have been crushed and earthed in the process, then the VLOM solenoids will always be switched on... So AFM is not so fail safe after all...

It's probably nothing to do with AFM, that's just where my brain initially when when @vf calais stated the engine starts on 4 cylinders. It could be one bank of injectors not plugged in, or some earthing issue, or some other connectors not plugged in, crushed wiring, or any manner of shut...

So yes, it's likely something is not plugged in correctly... but I'd go back to the mechanic that did the work and have him get his hands dirty

 

[vf calais]

Thanks for the replies lads...

 

[Skylarking]

Let us know the final outcome

 

[vf calais]

The cats been in the shop now 2mnths diagnosed as lifters due to ticking sound when starting, mechanics replaced lifters and everything associated with it, valley plate and what not...upon starting the car after everything was put back together and cold starting, informed me that the car was only using 4 cylinders when running, now hes getting some dude from Holden to hook up a laptop to the car and said that it may just need reprogramming to get the other 4 cylinders to engage...im confused...

 

[07GTS]

what 4 cylinders arnt working ? just the actual dod ones or a bank side ? there is no way the ecu can command dod at idle as it needs minimum rpm and speed and time and many more to all met parameters requirements to disable the lifters, if it is the dod lifters then id think maby something wasnt put back together right when they were changed maby plug under the valley to the solenoids for them, if ur in dod mode then the dash will display it but if not then its more a mechanical issue, just some ideas to think about