Please help VX V6 cannot find problem

[Allistair]

Hey guys new member not that great with cars and I am struggling to find the problem I am having.

A few months ago my car started stuttering/choking/struggling when accelerating and especially when reversing. It makes the car die and I have to start it again, its only happens when I am going slow. When I get up to speed around 60/km if I hold it there it feels like its stuttering. And when it is around 1000 revs there is a drop in revs and a 0.5-1 second delay in acceleration. I have gone to a few friends to try and fix this and so far I have changed; Spark plugs and leads, fuel filter, MAFS, coil packs. I have cleaned as best as I can around other sensors and have removed and cleaned the IAC Valve and the throttle body. I cannot think of anything else this could be (as said above im not great with cars) any help would be appreciated and I will answer any questions the best I can.

 

[losh1971]

Could be coil packs. Grab one from the wrecker and swap it over until you find the dodgy one. Also could be throttle sensor if auto. Are the gear changes being a problem too? If yes that indicates TPS.

 

[Allistair]

Could be coil packs. Grab one from the wrecker and swap it over until you find the dodgy one. Also could be throttle sensor if auto. Are the gear changes being a problem too? If yes that indicates TPS.

Sorry I've also changed the coil packs made no difference. Car is auto so I'll have a have look at the throttle sensor.

 

[Lex]

When changing the coil packs, did you also change the dfi?

 

[Allistair]

When changing the coil packs, did you also change the dfi?

No I did not change the DFI. Do you think that could be the problem, and would that show up on error codes?

 

[Lex]

Not sure about the scan?
Sometimes with mine it wouldn't show on scan.

Generally with mine when changing the coils, l would also change the dfi too.

You may have more than one problem?

Have all the parts you have changed, were they new or used?
If used, were they of a car that was running normally?

 

[Allistair]

Not sure about the scan?
Sometimes with mine it wouldn't show on scan.

Generally with mine when changing the coils, l would also change the dfi too.

You may have more than one problem?

Have all the parts you have changed, were they new or used?
If used, were they of a car that was running normally?

Most of the parts were new and I had someone look over and inspect the used ones, they were in really good condition and none of them made any difference to the problem at all. I'm trying to avoid going to a mechanic ($$$) but I cant seem to find what this is.

 

[Lex]

Try changing dfi & coil packs with one that is known to be working.
When you dfi plug of, inspect it for any signs of arcing. Also inspect the loom.

Can you hear the fuel pump prime for a few seconds when turning the key to ignition but not starting?
If not, it could be the fuel pump regulator (easy to check. replace it) or the pump itself.

Start first with whats easy.