The Rig

iTrader: (13)

As you do, sometimes, not always, i do this,as im young and stupid, and it accelerates,hits boost and doesnt like it,kinda holds back,coughs a bit, then whooooosh, off it goes.

only does it in 1st gear,dunno if its because i poodle about most the time and only do this now and again, or if there really is a fault, or if its down to ****e fuel.

sometimes, its fine,but as i dont do it everyday hard to say.

MY95,wrx,using v power.Standard engine.

Any ideas ?

james-wrx

Try pulling away while feathering the throttle before you nail it!
Or pull away at much higher revs

The Rig

iTrader: (13)

LOL, that wont help !!

The Rig

iTrader: (13)

Basically,its when the boost gets to about 0.8 bar,so its when boost kicks in.

james-wrx

If you launch it on full boost one of two things will happen
1. You will fly off into the sunset ! and smell clutch !
2. You will hear a nasty noise, revs will go round to limiter but you will be sat still wondering what the F$$k has happened
there is a bit of an art to it, if you dont give it enough it will bog down !
Give it too much and you will fry your clutch !

wanted

I had same problem with my first scoob. Took it to loads of specialists and noone could find the cause, it's one of those problems that you end up trying all sorts to fix. It went in the end when I had loads of upgrades but couldn't tell you what finally fixed it because I used to drive around it, then one day when I floored it I noticed it had gone. Bloody annoying though while it was there and not knowing what it was

The Rig

iTrader: (13)

James,none of what ur suggesting happens, i know how to launch etc etc

i pull off steady in 1st then once doing say 5-10 mph i floor it and thats when it happens, i steadily pull off,floor it, it like,hits a limit,then goes past that and shoots off.

no clutch bruning here,know all to well how delicate and ££££3 they are,been there/done that before !

The Rig

iTrader: (13)

Wanted,i prob will never find an answer !!!!

cheers

wanted

Probably not mate. I changed loads looking for the problem, but none of the specialists could find it. It was like a the engine was having a cough half way through first gear. It didn't happen in any other gears. Good luck if you are gonna try and find it.

I've just re-read your post and mine was a MY96. Same engine, maybe just coincidence??

vessy

I've had the exact same problem on mine since i've owned it!! Know exactly what you mean, mine sometimes does in in 2nd now, just as boost comes up a hickup in power.

We've tried loads (just search for posts under my username) one thing we have found is that it leans out at this point, leading us to a fuel starvation problem, the rapid rise in rpm and boost during 1st gear WOT may be quicker than the fuel pressure can rise, either down to weak pump or regulator. I will be fitting Walbro and uprated FPR within the next few weeks so will report if it fixes problem.

Mine is late MY95 UK.

Midlife......

iTrader: (2)

AFAIK Scooby ECU's are designed to protect the drivetrain in low gears so boost is reduced.......AndyF describes this quite nicely on one of the last posts in drivetrain on thread about mapping on rollers versus road.

HTH

Shaun

PeteBrant

Not if you are flooring it to get a quick start you don't

You want max torque - not max revs. i.e around 4800 rpm on a MY95 IIRC.

vessy

Having lived with this problem myself for a year or so it doesn't matter how you launch, it can happen at half throttle in 1st, just as boost comes up around the 3500k mark. if you pull away slow then once rolling plant your foot down you get a surge of power followed by about a 50% reduction in power for 1-2 secs then full power again. Boost is up at normal levels and doesn't drop at all whilst this happens, it's not fuel cut either as proved by datalogs. Sounds same problem as mine, just need some good weather to change the pump and reg!!

The Rig

iTrader: (13)

robsw

Excuse me for digging up old posts but I have the exact same problem described in this thread on my MY93 WRX.

I get like a big cough after full boost is achieved always in 1st and sometimes in 2nd.

As vessy says above my afr guage shows me being lean when it happens, so seems to be fuel starvation, could it be my fuel pump or MAF? I don't want to just change bits for the sake of it to find it isn't the problem.

Any help will be most welcome as this is driving me nuts. I have replaced the coils, and plugs with the correct gaps.

Robin.

Claaarkio

iTrader: (1)

I would guess at the ecu trying its best to keep up with the raising revs and sorting out the fueling but being a little slow?

Dave

robsw

Thanks for the response Claaarkio.

What do you think would cause the ecu to react slowly in the fueling department? Tired MAF sensor? Fuel Pump? FPR?

Claaarkio

iTrader: (1)

Not sure what would cause it, i know i get a blip, then a punch in the back when it sorts it self out and flies off, i like the feeling, but maybe some ecu's don't act exactly the same way ?

like you say MAF etc could all contribute to the symptoms you describe.

Dave

robsw

Thanks for the comments Dave, most appreciated.

Has anyone out there had and solved a similar problem, or any other ideas?

Robin.

911

Not being rude at all, but have you tried to keep away from the rev limiter?
Shift from 1st to 2nd 500 rpm sooner and WOT it in 2nd

Bit like this:
DropShots Day

robsw

Nice pull away!

I know what you are saying but it won't help as it coughs just after boost comes in 1st gear, at about 4000rpm.

I get a split second of pull on full boost, cough, then pulls again to the redline, the level of boost remains constant throughout.

Any other ideas?

Robin.

scoobysmiff

iTrader: (2)

is it a chesty cough or more of a wheeze? i cant believe the other one went woosh as well, how do you get it to sound like that???

robsw

It coughs as in a complete loss of power for a very short moment.

911

OK!

It is fuel cut: when the ecu sees a spike in the boost it cuts the fuel supply to save the engine, after a second or so it feels all is safe (the boost has instantly died and resumes normal service, )hence the instant pick-up.

Possibly is more prone to it when the air outside is cool and moist (bit like the summer we have).

A stock engine with a 3'' decat is very prone to this.
The cut is quite violent?

I had this on the car in the vid above and fitted a boost controller years ago which certainly cured it a treat.

Today I would invest in an Apexi FC and get it well mapped and that will fix it and give you a nicer engine.

Graham.

Sprint Chief

I had exactly this problem on my96 UK turbo.

Solution? New set of spark plugs, keep the gaps smaller than recommended (try around 0.65). Check coil packs at the same time (mine were fine). Problem solved (well, for me anyway )

robsw

Graham, unfortunately it is not boost spike, I have had that before. The cut in power I get is not as violent as fuel cut. Also on the guage the boost level remains constant during the cut.

Sprint Chief, I have also replaced the plugs recently, and gapped them to 0.6mm, so it is not that either. I also have new coil packs.

Thanks for the suggestions, please keep them coming!!!

Robin.