Lettuce

iTrader: (1)

Have noticed a problem on my 54 plate STi PPP, basically when pulling off in 1st gear, after getting to the bitting point of the clutch and releasing the car pulls away and then straight away there seems to be a split second loss of power and then the engine picks up fine, you can see the revs drop of for this split second and then raise again. The engine seems to perform fine after this and has loads of power else where, its just this initial power lose from a standing start.

Could this be related to the sparks needing replacing?

TonyBurns

iTrader: (3)

Errrm, thats down to the driver if you're doing standing starts its called bogging down, its where you drop out of the power zone, you either need more revs, more practice or launch control

Tony

JDM_Stig

iTrader: (3)

4500 - 5k revs and dump the clutch

Myles

iTrader: (40)

EFA

Rob Day

iTrader: (78)

Sit the box in neutral, from tick over blip the throttle once, does it hesitate now? Might be that its just not getting enough fuel. If it does hesitate try holding the revs at say 2k then blip the throttle, any hesitation now?

EDIT - What mods?

Rob

Lettuce

iTrader: (1)

Well a mate who has a hawkeye drove the car and noticed it as well and says that his doesn't act that way.....or thought I know they have slightly different engines. I also notice it when pulling away slowly obviously it's not as pronounced but still there never the less.

I'll try what u suggested rob when I ger home, the only mods the car has is PPP

Lettuce

iTrader: (1)

Rob just so i understand you, sit in neutral blip the throttle and the pull away??

Rob Day

iTrader: (78)

No Pulling away, just as described to see if there is hesitation at the bottom on the rev range. If your car has already been mapped then I would be speaking to 'the' mapper about it.

So - Neutral, tickover 850rpm (guessing), blip throttle..... what happens, does it climb ok.

Or - Neutral, hold revs steady at 2'000, blip throttle..... what happens now?

Rob

scubbay

iTrader: (61)

Neutral position switch perhaps?

Lettuce

iTrader: (1)

Ok have done what you suggested rob and seems fine.......

http://www.youtube.com/watch?v=tcN5nwG-fhY

Alan Jeffery

The chances are it's fine, but just to humour me check the intake hoses in case you have a loose clip downwind of the MAF sensor. I'm relating the issue to the engine moving on take up. Been there, seen that!

Lettuce

iTrader: (1)

Tried the 2 large clips (is there more?) and all seem tight.......

Rob Day

iTrader: (78)

Lettuce, seen as your up for posting vids and pics, post some footage of the actual issue to see if it stands out to someone what could be causing the issues.

As for the Neutral Position Switch, I think the issue would repeat in all gears once the heavy end of the torque is pushed through, and also its likely to flag up the engine check light.

Obviously we are all clutching at straws trying to help you on a Forum, but another idea could be to buy a OBD2>USB cable and freely download "learning to view", at least this way you can monitor it. Failing that I would talk to a mapper "nicey"

Rob

Lettuce

iTrader: (1)

Cheers Rob, ill try and stick my iphone to the dash whilst driving somehow lol.

Im not versed on OBD2 to USB and Learning to view...what is this???

Something like this......

http://www.buyandfun.com/product_inf...roducts_id=908

bigsinky

now that would depend on the clutch.

Cocker

iTrader: (3)

Mine does this a bit aswell mate (53 STI PPP), when pulling away gently with hardly no revs, its like its fine when the biting point engages but then sharply drops by about 2-300rpm just as the clutch is fully realised. Either dial in some more throttle, or i put it down the maybe the clutch being a bit worn?

Rob Day

iTrader: (78)

That should be fine, I used a VAG lead from eBay, installed the drivers that came with it, binned the VAG software and downloaded learning to view software, you cant do any damaged with LTV as it only reads the ecu and resets it. Rob

Lettuce

iTrader: (1)

Have been looking at the logworks software for the iphone, but appears to need a wifi obd2 device to talk to the iphone....not sure if any old wifi obd2 device will work or not

Lettuce

iTrader: (1)

Sorry about the long delay in getting back been busy and not much time to sort this out. Anyway have taken a vid as best i can on a quiet industrial estate road, sorry about the camera shake. Basically start and stopped 4 times each time getting a bit more aggressive and releasing my foot of the clutch faster with each start. As you can see from the very last one the camera shakes a hell of alot and you can see the revs drop off........

http://www.youtube.com/watch?v=xc5UcTh1Lyk

Rob, I have a OBD-II device now, what am wanting to recorded/measure with Logworks??

Rob Day

iTrader: (78)

Looks like its just bogging down due to a lack of "launch" to me. If you want to launch the car you need more turbo spool thus higher revs too.

Download learning to view here http://www.romraider.com/forum/topic2772.html

Rob

Lettuce

iTrader: (1)

So more that 2000rpm for a normal gentle pull away, surely i should have to give it more than that if im pulling away slowly to stop it from bogging down all the time.....this is however my first
turbo car.

So to get launch i would have to rev at just over 3000rpm then release the clutch?, as thats around when the turbo kicks in??

Rob Day

iTrader: (78)

For normal driving do what feels right, if it doesnt feel right then something is amiss somewhere. However looking at the vid it doesnt look to bad.

As for a Launch, you need to be looking at somehwere near 5'000+ rpm, but Im not taking responsibility for any damage caused, ie clutch, gearbox, drive shafts etc. If you launch at 3'000 then you will bog down, and by literally reving up from tickover and going the turbo will not be primed enough to get you off the line quick. Look at some example although they are running more power then yourself and uprated clutches. Mine is the Silver Bug, but even with an uprated Organic my clutch slipped through the power.

Lettuce

iTrader: (1)

Must admit I can get it to pull away without it doing it, I just have to hold the clutch at the biting point for alot longer than what I used to whilst feeding the power in, I'm just not sure how much wear this is putting on the clutch?.

My last car was a civic type r so maybe going from that that you could rev the nuts of all day and there was the same constant power all the way up to 6000rpm when the 2nd cam used to kick in to a turbo fuelled STi maybe isn't the best comparison??? As I have noticed sitting in neutral in the civic compared to the STi the revs used to pick up alot quicker on the civic than the STi when blipping the gas pedel!

It feels to me that the type R would murder the STi off the block for defo the first gear and maybe the 2nd but as soon as you got the STi in the turbo band then it would reel the type r in pretty rapidly. Maybe it's just the STi is fast it just doesn't feel it going from a go kart like type r to a more solid STi??