VS V6 drops power sometimes!!!

[skootaroo]

My VS wagon has not had a lot of use latley as I've been riding my bike but it has been playing up on me all the same. I've been a good lurker here and look after my beast well but I have never read the symtoms my car is demonstrating here.
Only when hot and only when gently accelerating it loses power like it is on 2 or 3 cylinders. If i'm cruising along and just need to add a bit to get up a hill it goes to LOpo mode and limps up the hill whereas if I had just stabbed at the throtthe it will take off at full power and charge up anything indefinatley.
When it fails, I can go to full throttle and it will always keep running but I could end up creeping over the top of the hill at 30 or something just as embarrassing and then just a couple of secconds at idle and I'm back to full power again.
I've changed plugs, leads, coils. I've checked my cat, it is intact. I cleaned my maf.
I thought it was spark I was losing at first but it is so much colder now and we have had a lot of wet weather, it is no worse, what could cause this in the fuel system?
If anyone has some good theories I'll check them out, I need to take my mates away in two weeks and need this resolved!

[hako]

Try changing the fuel filter....also maybe the fuel pressure regulator is playing up.

[skootaroo]

I was thinking fuel filter early on but I managed to sustain full power for a long enough period to exclude that!
How do I test my pressure regulator?

[hako]

You can pull the vacuum hose off the regulator and if its full of fuel then it's buggered. Otherwise you really need to check the fuel line pressure...this can be difficult as the pump puts out about 40 Psi and you don't want petrol spraying everywhere. Try driving with the vacuum like disconnected (plug it) and see if there is any difference. The fuel filter may still be the problem...they are cheap to replace anyway.....also possibly it may be the pickup filter sock thing inside the tank.
Do a codes check as well. Coils or DFI module????

[kbelt66]

Hey scootaroo
Just an idea but it could be the air flo CPU??
I have had the same thing.
Thats what we found.
Cheers KB

[immortality]

Just an idea but it could be the air flo CPU??

do you mean the MAF?

[moff_man]

the air flow meter, or tps, not sure if you tried a tps on this one (cant remember if it was you in the other thread) but tps will cause issues at certain throttle positions, the tracks were and they drop out, also it has been know for the air flow meter to stuff up or get blocked

[bandidoben]

have you cleaned your intake? air filter maf throttle body?

[skootaroo]

Thanks for the thoughts, all my intake is clean, including the MAF, I have just swapped over the throttle position sensor, nothing looked wrong but the proof is in the driving, and yet to be seen.

[kbelt66]

Air flow sensor????
Which is what i ment when i said CPU...
The chip can die and all you can drive with is idle speed( once it s died) been there.....
But hey just another suggst to look at????

[skootaroo]

Kbelt66 the MAF is the air flow sensor.
The TPS was not the culprit either, so that leaves???

[skootaroo]

Its not the DFI module either, I swapped it out and the problem is still there. Now I think that means I have replaced the enitre ignition system.
Are the ecotec fuel injectors batch fired or sequential?