losing boost??

[DBIMPREZA07]

i currently have a impreza wrx however just recently it seemed a tad slower and yesterday wen i took it out and booted it at 6000 revs the car stuttered for a second (like the acceleration just stopped all together) and then it kicks back in again??is this because it is losing boost??

[Muffleman]

Get a boost gauge fitted and watch it. However, boost isn't likely to just stutter.

When did you last change the plugs ?

[Vixpy1]

What mods have you got, it could be plugs, boost cut, coil packs...

[DBIMPREZA07]

i have only just bought the car and are'nt to sure when the plugs were last changed....im very new to this turbo stuff lol...my first turbo car

[shadowninja]

Could even be a split hose.

[stevieb]

Possibly a dodgy MAF

Edited by stevieb on Sunday 2nd September 12:56

[DBIMPREZA07]

wots maf??

[stevieb]

Mass Aif flow meter.. Give the ECu the flow rate of air onto the engine and the ECU combined with a few other things control the fuel and ingition timing. If the MAF is not working then the fueling will be completely wrong.

Have you fitting a induction kit or anything recently

[DBIMPREZA07]

it has an induction kit but i didnt have it fitted so im not sure mate...thanks for the info

[stevieb]

Have a search on Scooby net, I do not know what year your car is but the MAFs are weak on some of the Classics. Maybe worth having a check with error codes.

[ScoobieWRX]

On a standard mapped Scooby WRX the boost tails right off at 6800rpm. Between there and 5600rpm boost is back up to about 11-12PSI. Keep your revs between 4800rpm - 5200rpm for max take off and max boost at about 13psi-14psi at that rev range. Any higher and you're off boost.

I know because i do my own mapping and i've just had a look at my standard map for the 02 WRX. Plus the TD04 turbo gives best boost lower down the rev range and spools up a bit quicker than larger turbos that are better higher up the scale. On the TD04 Turbo by about 5200 or so rpm you're running out of boost so you want to keep all the action between 2500 - 5000rpm, plenty of mid range acceleration.

Also don't snatch the clutch up when taking off....feel and feed it in from just a fraction below it's biting point and deliberately bring your foot up. Try and do this too quickly and the car will bog down lurch forward a foot or so and die on you then crawl a bit until the boost is coming back on. I know i've done it a few times until i perfected the take off in my own car.

Hope this helps

[WeirdNeville]

only a suggestion but check all the pipework into and out of the intercooler (sitting horizontally on top of the engine if it's standard). A mate of mine had similar problems after an engine rebuild, they hadn't bothered to tighten up the hose clamps onto the cold side of the intercooler, which casused similar symptoms to those mentioned.

[DBIMPREZA07]

fixed it would seem that 1 of the fuel pipes wasnt connected ...good job i noticed it when i did could have made engine blow up!

[ScoobieWRX]

How does it run with a fuel pipe unconnected. Would it not spew fuel everywhere and therefore you would have smelled it??

Glad you're still in one piece and not barbecued to be able to post a reply