MR2 overboosting problems need help BAD! - Toyota Nation Forum : Toyota Car and Truck Forums

IMPORTMyth01 · 01-15-2004, 12:16 PM

Whats Up TN,
I've been everywhere and I've looked throughout the whole forum for a solution before I asked...

I bought my MR2 about 7 months ago and still havent run into anyone who I can just talk and ask questions to. I have ony seen like 4 on the road and they are all stock.

My motor is old and I know that but it ran fine at the track and fine for a while then all of a sudden I couldn't control a steady boost level. The car will run perfectly fine until you full throttle it. In first gear it will boost like 12 lbs, second gear like 14, and then halfway through third the car will hit fuel cut. I thought it was the wastegate actuator that went bad so i bought a brand new one a 7lb one at that. And even if I run the vaccum lines straight fron the turbo to the actuator it still boosts like 17lbs. The Boost controller will help very little but not enough to stop it from hitting the boost cut. I just need to know bottom line if there is a way to fix it or should I just say forget it and buy a whole nother motor.

Any comments or replies would help.

Ran 14.2 @ 9lbs. At Montegomery AL.

***MRQtwinturbo*** · 01-15-2004, 04:23 PM

what kind of boost controller are u using??.....

IMPORTMyth01 · 01-15-2004, 09:32 PM

Turbo XS dual stage...but that doesn't matter because ive tried 2 other manual boost controllers, and even running it like stock and it does the same thing... And what frustrates me the most is the fact that I took a vicegrip and clamped it to where the wastegate was completely open and it still did the same thing like as if i had the boost set on 25lbs.

Tony Hudson · 01-16-2004, 07:41 AM

Check out the UK IMOC group at
http://autos.groups.yahoo.com/group/imoc-uk/
Its a very busy MR2 site and I am sure you will get assistance there. You will have to register to post a queery. HTH.

Tony

MR2QuiK · 01-18-2004, 05:57 AM

when you install a manual boost controller you have to disable the T-VSV, failure to disable the T-VSV with a MBC allows excess pressure you bleed away from the wastegate. This can lead to boost creed or boost spikes thats whats causing it to creep up that high.
simply remove the hose from the wastegate to the T-VSV and plug both ends. if you have any questions just pm me.
hope i was of some help.
Gio