Engine Problems at 80km/h

[kiddyl]

I'm having problems in my VX cruising at about 80km/h. The car seems to mis-fire at about 2500 rpm under load. It's very ovious up-hill. At first it was only slight, but has since gotten worse. I had a feeling that it was electrical and that after I serviced it, it would go away. But after changing plugs, leads, filters etc; it's still there.
A mate had told me that it was the transmission trying to kick down a gear at that speed due to wear. And I thought so too. But I have just realised that planting my foot in neutral, you can feel it struggle to rev progressively and seems to do the same thing!!
So now I'm back to where I started. I think it's electrical as it seems very bad under load. My thoughts are it's either the coil packs or a knock sensor of some sort. Or even the CO2 sensor maybe???
Does anyone have any ideas???

DYL

[SSbeast]

possibly failing coil packs my old VR did the same when they were about shot. Soon it'll drop a cylinder all together.

[kiddyl]

What are they worth to replace?

[vt s]

Does it drive fine under normal conditions but when you plant the foot or as you said meet a hill it misfires?

[Longman]

Dude,

Before you go spending $$ on coils, check the basics, plugs and leads, I'll bet you it's one of them. I had the same problem, one of my leads was stuffed, they just wear out over time. If they are all OK, then look at the coil packs.

[kiddyl]

Nah like I said, I replaced all leads and plugs. And nah not just when I plant my foot. it's all the time, when it drives past 2500rpm. Taking off from the lights is shocking. ESPECIALLY up hills. I have to shift it back to 3rd to get to stop carrying onn.

[vt s]

If only at certain revs pssible it could be cam sensor?..
Ive had someone have same problem as you spent over 600bucks replacing plugs, leads, coils and what not when turned out to be $50 cam sensor...

[kiddyl]

ok. I'll keep that in mind! cheers

[S.O.S]

Is the lock up torque converter going in to early ?.

[kiddyl]

Is the lock up torque converter going in to early ?.

What do you mean??

[Kernal]

did u replace the fuel filter?
or maybe need a new fuel pump

[kiddyl]

did u replace the fuel filter?
or maybe need a new fuel pump

I replaced the fuel filter about 2 weeks ago. Yeah.

[greenacc]

Did you check the error codes ? It could even be your TPS. they are just a fancy variable resistor and when they stuff up they create symptoms like this.

[kiddyl]

Did you check the error codes ? It could even be your TPS. they are just a fancy variable resistor and when they stuff up they create symptoms like this.

Thats the thing there's no errors or anything. It's basically just mis-firing at a certain part in the rev range (2500rpm). And its most noticable under load or when cruising at 80km/h. I dont know if the coil packs fail on them but imagine an older cars plugs when they foul up and runs like shit. That how its running...
Taking off at the lights its farts and carries on until it hits about 3000rpm then beautiful...

[S.O.S]

What do you mean??

You know when you get up around 75-80 is it the torque converter locks in like a 5th gear ?. Sometimes they like mine feel they come in too early and it makes the car sluggish and it wont pull up a hill until it drops back. But up @ 100 it's fine.

[kiddyl]

You know when you get up around 75-80 is it the torque converter locks in like a 5th gear ?. Sometimes they like mine feel they come in too early and it makes the car sluggish and it wont pull up a hill until it drops back. But up @ 100 it's fine.

Nah definately not that mate! It's more a jerking action. Might have to get a mechanic to have a look i think. Its a pain in the ass now taking off at the lights!

[S.O.S]

Nah definately not that mate! It's more a jerking action. Might have to get a mechanic to have a look i think. Its a pain in the ass now taking off at the lights!

Does it idle bad at all ?. I wonder if it's more transmission then engine ?. Not sure don't know much about these Auto's.

[idb]

its a dfi moduel

[kiddyl]

Does it idle bad at all ?. I wonder if it's more transmission then engine ?. Not sure don't know much about these Auto's.

Nah doesn't idle bad at all. But If I give it a rev, it hesitates before it picks up again!

[kiddyl]

its a dfi moduel

What is a dfi module??

[S.O.S]

What is a dfi module??

It's a mystery ?.

DFI is under the Coil pack i believe ?. you can just grab a cheap one from a wreckers for about $40-$50 and see how that goes, easy to change over.

[HARVZ-6]

dfi modual basically controls the coils,

easiest way to check is try another that works

if not get a workshop manual and follow the steps to check

[Alloytec]

i assume its a v6 emotech ?

look under the throttle body there is this little hose which goes to the egr (?) i believe on the drivers side at the back near the dipstick tube., it has a little L piece from the bottom of the throttle body then this hard plastic pipe pushes into that, the pipe then weaves thru the manifold to the oposiste side, check this to see if its come off, really common fault a good fix is to glue the hard plastic pipe into the rubber L piece. hope that made some sort of sense, its been a while since ive seen a v6 lol