V6 struggling below 3000 rpm

[Cavalier342]

I thought it was to do with a heavy flywheel and high gear ratios, but I swear it doesn't feel right...

Say I do a quick launch, not wheelspinning or anything, just get off the biting point and boot it... until it gets to 3000 ish rpm, it feels like it's really struggling to pull. After it gets to 3000 rpm, it's like a nuclear reactor comes online and it just takes off. This is the same in any gear. I'm trying to eliminate what it could be.

Thinking so far...

Fueling problem, either dirty injector/s or fuel pressure regulator.

HT leads worn out, or distributor.

Throttle position or another sensor.

The second sensor in the air inlet trunking, not the MAF sensor but the one before it.. Not quite sure why it's there.

Heatsoak from the standard airbox with standard filter which is a bit past it's date.

It doesn't missfire at all, nor does it miss a beat, and does make a bloody good growl, but just feels totally underpowered at the low end...

[humbucker]

Mine launched immediately without hesitation, although yours is an auto if memory serves?

Breathers cleaned? Given it a thorough service lately? I guess not if you're saying that the air filter is past it etc

[TurboDan]

Its not thetraction control is it?

Any lights on the dash?

[Hayward691]

Could just be lag... And the auto box...

[Cavalier342]

It's a manual Don't know where you guys got mixed up but no, it's a manual.

Serviced it with the help of Dave a couple of months back. Replaced everything, including fuel filter. No lights come up on the dash at any time. Breather hoses are clear.

I tinkered about with it just now, managed to remove the box behind the front bumper, renosanse box I think Squig called it. I looked through his V6 tuning How 2, and followed some tips.

With the box removed, the air should now be less restricted and less heat soaked as it's drawing it from underneath, and it's separated from the rest of the engine bay by a plastic liner. Got it hot, gave it a blast up and down the road, didn't feel any different, but I think it felt a little more willing in second when picking up. Or that could just be the lack of fuel in the tank

I'll wait and see how it goes, it is hot this afternoon bare in mind, so it won't run at it's best anyhow.

[James McGrath]

When you say it feels sluggish, is it as slow or slower than your 1.8 or just relatively slow?

It is a multi valve engine so I imagine all the power is at the top end.

Could also be the gearing. It's extremely steep and the gaps between the gears is huge in comparison to the 1.6 and 1.8 which really have a close ratio gearbox.
For example if I do 30 MPH in 4th gear in the CD or Diplomat the engine would be barely ticking over at just 1100 RPM and that's just the C20NE, I imagine the V6 is even steeper.

[Cavalier342]

If I gently apply throttle, in any gear below 3000 or so rpm, I can feel it accelerate a bit, but if I floor it, it just isn't pulling right. Feels like it's towing something. And as I said, anything over those revs, it takes off.

[TurboDan]

As i said, are you sure its not just the traction control kicking in? As on the v6 all it does is basically close the throttle abit which stops/eliminates any wheel spin.

It does sound like your description.

[Hayward691]

Could be fuel pump... Cant get the preasure right for the demands of excelleration...
Do you want to swap?

[Lowrider Dave]

I need to drive this to see what you mean. I know we cleaned the breathers and changed the plugs, i doubt the filter would be effecting it that much - could always whip it out and give it run down the road just to make sure. Other than that, fuel starvation or check for stored codes. Check TC light is not on...not that it stopped me wheel spinning in 2nd.

[Cavalier342]

As i said, are you sure its not just the traction control kicking in? As on the v6 all it does is basically close the throttle abit which stops/eliminates any wheel spin.

It does sound like your description.

I was under the impression that traction control is only active when you press the button. I can't see it wheelspinning at 2000 rpm at all in the dry...

[Cavalier342]

I need to drive this to see what you mean. I know we cleaned the breathers and changed the plugs, i doubt the filter would be effecting it that much - could always whip it out and give it run down the road just to make sure. Other than that, fuel starvation or check for stored codes. Check TC light is not on...not that it stopped me wheel spinning in 2nd.

Gonna have to arrange a day where I can pop down to yours mate, then ye I'll be glad to show you.

[Cavalier342]

Thinking throttle position sensor too.. I've cleaned out the MAF sensor today, and the one in front of it.

[Super89]

When you press the button and it shows the light on the dash, this means the tc is switch off..

[Cavalier342]

no it doesn't It's the other way around.

[TurboDan]

As i said, are you sure its not just the traction control kicking in? As on the v6 all it does is basically close the throttle abit which stops/eliminates any wheel spin.

It does sound like your description.

I was under the impression that traction control is only active when you press the button. I can't see it wheelspinning at 2000 rpm at all in the dry...

No the Traction control is active all the time, only when you press the button it then turns off and the TC light shows on the dash to warn you that its off.

Go and try flooring it with the tc turned off (ie. push button so the light comes on the dash), and report back and see what happens.

[TurboDan]

no it doesn't It's the other way around.

Nope Super89 is right.

TC light lit up = Traction control Off
TC Light not lit up = Traction Control on

[Cavalier342]

I feel really thick... Will report back sir!

[planetc]

Coupled with the perfect description of working traction control it is highly likely that we have just diagnosed your 'fault' lol

[gsi pie]

epic thread

[TurboDan]

Hmm hes not back yet... lol

Maybe we should of warned him about tourque steer etc... Hes probably not experinced it before.

[Hayward691]

Coupled with the perfect description of working traction control it is highly likely that we have just diagnosed your 'fault' lol

Hope its as simple to fix as pressing 1 button... lol

[humbucker]

Haha oh come on we've all been there, easy mistakes to make and all that. I remember calling the AA out cos my car suddenly wouldn't fire up. I parked it up the night before without issue then when I tried to start it the next day it wouldn't even splutter into life, but the ignition would 'click'. The AA man turned up, looked at me like I was a lunatic, put my automatic gearbox from NEUTRAL into PARK and turned the key. The look on his face was priceless, he was so annoyed! Wouldn't have been so bad but I'd owned the car for 3 years at that point hahaha!

[Hayward691]

Love it!!! I have spent a few months fault finding a misfire and getting nowhere... Son pulls out ht lead (he's 8), burnt through... Says to me... "I think this is your problem.... What does this bit do?"

Brilliant

I have also sat there for about 20mins.... In drive... wont start... great, I bought a lemon!!!!

[Cavalier342]

hang on, hang on, let's not crack the whisky open yet, I haven't solved the problem yet, just have to see what it's like tomorrow when I drive it.

I doubt it is that to be honest, it just doesn't feel like it'll wheelspin enough to cause traction control to kick in.

And yes, going into 2nd at a lively speed with a quick shift, I do get very nice torque steer