Boost Controller Causing Grief.

[jimgt4uk]

Hello,

I bought a manual Boost controller for my car and fitted it yesterday, after letting it warm up and taking it for a quick spin down the road i noticed the boost guage shot up past 20psi so i stopped and turned it right down to 8psi, after about half hour of driving i i got out of the traffic and gave it a bit of throttle when the rev meter went past 3,000 rpm the power went and the car coughed and spluttered and backfired so i let off its fine as long as i dont put my foot down it will rev all the way to 6 and a half but only slowly as my foot is only half way down, i took the boost controller out to see if that was causing the problem but now it still does it it never did befor i fit the controller, i really have no clue what is wrong. does anyone else have any thoughts as to what the problem might be?

Cheers,

Jim

[Bibbs]

Did you add in an FCD to get rid of fuel cut?

I think your car will have detected a MASSIVE boost increase and then cut the fuel (so it doesn't blow up) ..

re-set your ECU .. then get an FCD, tap it in.

[jimgt4uk]

no i dont have a fcd fitted good point! The fuel cut normally kicks in about 15 psi doesnt it? and if it hit more than 20psi that would have caused it to cut.

Do you know how i could reset the ECU? is it a case of just pulling the fuses in the engine bay fuse box?

Cheers,

Jim.

[Bibbs]

Yeah .. after you hit the cut, your engine light will come on.

You'll then not be able to get +ive boost untill you turn the ign off and on.

If you do it 3 times, it'll stay perminant (until the ECU is reset).

And yeah, just pull the EFI fuses ;)

[jimgt4uk]

Ah, thing is the dash ecu light isnt on i know it works cause the knock sensor failed a while back and it was on for a long while till i found out how to do a diagnosis with a paperclip. and i do still get positive boost aswell, it only splutters when a push down over halfway on the accelerator its a very strange problem i thought it might have something to do with the timing.

i will reset the ecu anyway and see if it solves it ill also put it in diagnosis mode see if that says anything even though the ecu light isnt on.

Cheers,

Jim

[Bibbs]

I'm going by my MR2 Turbo .. the GT4 may have been a different setup - but it defo sounds the same.

[jimgt4uk]

Ill reset the ecu before my journey home from work tonight and see if that solves the problem.

I have just ordered a fcd so that should be here in the next day or so, do you know what colour ecu wire it should be joined into by any chance?

Cheers for all your advice by the way.

Jim.

[Bibbs]

not off hand .. what you want is the "pressure signal" .. go to www.apexi-usa.com and download the AVCR install manual (under Documents) .. it *should* show you the wire ..

[GTForbes]

for a quick fix to see if it is the fuel cut coming in, unplug the pressure sensor in the engine bay and put a screw in it then re-set the ECU and take the car a run. this eliminates the fuel cut completely.

DISCLAIMER: if the engine goes pop from you turning up the boost then dont come crying in this direction, turning up the boost on a car should only be attempted if you know what you are doing