AU VCT lag

[adrian302]

got a au xr6 vct and getting alot of lag when i give her a bit, and especially around corners, any ideas???

[KR1STO]

explain the lag mate...
does it hesitate, feel like a flat spot, changing down gears slow..etc

[adrian302]

yea exactly lyk that

[Day-mow]

serviced the car recently?

[Jimmyd]

For starters you will need to eliminate common issues. I would recommend the following (assuming these have not been done as yet);
1. Service Auto - many find it surpirisng what a box full of fresh fluid will do for both performance and driveability
2. Check/replace Plugs/leads
3. Replace Fuel filter
4. Check O2 sensor
5. Reset ECU

Take for a drive and advise outcomes.


Cheers

James

[mik]

if the battery has been reset recently i`m not 100% sure on this but i think it resets the ecu to economy mode, this is what i found on my vct xr6, it took me a while to wake up why it felt a bit less spritely even my brother commented on this when he drove it.

[sd1800]

If it's around corners this would point me to Fuel Pump or Fuel Filter.

Filter is probably due to be changed anyway and the pump is only $55 off ebay.

[Grippy]

I had exactly the same problem you described when I had my old VCT engined XR6, mainly when accelerating after turning a corner. Turned out it was the fuel pump sock, quite a cheap fix

[SSD-85]

VCTs come standard with lag

Seriously though, I agree with the idea that its a fuel delivery issue, since its the only thing to really consistently cause that in a corner.

[grandpa_spec_F6]

Turn your boost up, install a black bonnet, altezzas, should fly then

I wonder if my fuel sock is clogged, I've done 184k on mine and it does sometimes seems to struggle so I know what you mean. Just did a major service on it which has made it a lot smoother than it was however I sometimes find when you give it some off the lights it sort of goes... but then starts to pick up the pace quickly at around 3k, or is that just the VCT?

[Jimmyd]

Define "you give it some off the lights it sort of goes... "

Video of my AU1.5 VCT Fairmont Ghia (traction control off) with 2.5 cat back, no other mods

http://s681.photobucket.com/albums/v...t=FILE0009.mp4

Cheers

James

[grandpa_spec_F6]

Sorry I'll clarify my statement. Foot flat off the lights, it feels like a dead spot, it starts to move, but around the 2.5 - 3k mark it suddenly picks up performance, the exhaust note changes to a sharper more aggressive tone, and the RPM's climb quickly.

[Jimmyd]

Originally Posted by grandpa_spec_au

Sorry I'll clarify my statement. Foot flat off the lights, it feels like a dead spot, it starts to move, but around the 2.5 - 3k mark it suddenly picks up performance, the exhaust note changes to a sharper more aggressive tone, and the RPM's climb quickly.

how does it compare to the video?

[grandpa_spec_F6]

Currently at work, they have blocked streaming video, will let you know once I'm home

[Day-mow]

How many seconds? That vid doesn't work oh my iPhone very interested to know tho

Originally Posted by Jimmyd

Define "you give it some off the lights it sort of goes... "

Video of my AU1.5 VCT Fairmont Ghia (traction control off) with 2.5 cat back, no other mods

http://s681.photobucket.com/albums/v...t=FILE0009.mp4

Cheers

James

[Jimmyd]

Originally Posted by Day-mow

How many seconds? That vid doesn't work oh my iPhone very interested to know tho

Around 7.5 seconds

Cheers

James

[Racecraft]

if it is a BTR 4 speeder and factory diff, you have to keep the car in a sweet spot rpm wise or it wouldn't pull the skin of a rice pudding

[MrAUII]

My forte is doing the same thing again. Had it service all plugs etc and 2 months on its come back.

[Bushbasher]

Originally Posted by grandpa_spec_au

Sorry I'll clarify my statement. Foot flat off the lights, it feels like a dead spot, it starts to move, but around the 2.5 - 3k mark it suddenly picks up performance, the exhaust note changes to a sharper more aggressive tone, and the RPM's climb quickly.

At least some of that is the VCT. My Fairlane is the same, feels a bit flat till it gets to 2500rpm or so then it gets up and goes much harder.


Bushbasher

PS. Try changing your driving style a bit and see if that helps. Instead of mashing your foot to the floor, try hitting it to about 1/2 throttle then progressively feeding it to full throttle. I think you'll find the motor will respond better as it won't just dump more fuel and air into the motor than it can process at low revs, it'll scavenge better and keep the mixture a bit leaner and closer to optimum for a better burn and so should make better power. It's a "seat of the pants" thing, lol, with a bit of practice you'll get a feel for it. ( I hope that makes sense,lol)



Bushbasher

[Jimmyd]

Originally Posted by Bushbasher

At least some of that is the VCT. My Fairlane is the same, feels a bit flat till it gets to 2500rpm or so then it gets up and goes much harder.


Bushbasher

PS. Try changing your driving style a bit and see if that helps. Instead of mashing your foot to the floor, try hitting it to about 1/2 throttle then progressively feeding it to full throttle. I think you'll find the motor will respond better as it won't just dump more fuel and air into the motor than it can process at low revs, it'll scavenge better and keep the mixture a bit leaner and closer to optimum for a better burn and so should make better power. It's a "seat of the pants" thing, lol, with a bit of practice you'll get a feel for it. ( I hope that makes sense,lol)



Bushbasher

Agreed - Driving a VCT effectively is very different to an I6 - bit like the differnce between drving a 5.0 Windsor and a 5.4 Boss.....

[Blue_Flame]

Where is the fuel sock you speak of? is it in the tank?
Also at the expense of looking stupid, where is the fuel filter?
I'm only asking because I have not actually got under the car and looked for it, didn't think of it when I was under there changing the HT leads yesterday
Thanks Guys.

Just did a search, found it.

[Day-mow]

Fuel filter is near rear left tire

[Blue_Flame]

Originally Posted by Day-mow

Fuel filter is near rear left tire

Thanks Mate, tight sucker to undo.

[Day-mow]

Yeah it's well gay. I had issues getting it to seal a few when I changed it. 3 goes got me done. Did get a face full of petty tho. Safety glasses win!