inconsistant boost

[Dan23]

ok basically when i drive the mr2 (rev2 turbo) and every now and then heavy throttle the car the boost neddle will go up to the top as it should, but if i drive the car hard through the rev range to almost red line after it doesnt wanna full boost, will only hit around 3/4 on the neddle. the car is running stock turbo, ic, etc and just has an induction filter and mongoose system on it, is this normal as i hear the stock ic are rubbish and if iv got a better air flow with the induction filter and exhaust is the ecu trying to protect the car or something? basically wanna know if its normal to be doing it

[smartdj]

Alreet, I'm sure iv herd the rev2 standard turbo drops off at higher rpm unlike the rev3 standard turbo, try pulling all the boost pipes off and check for leaks.

Do you have a aftermarket boost gauge?

Also maybe check for fault codes. Very easily done with a paper clip. Can remember the terminals but I'm sure a quick search would find them

[Super_red]

Rev 2 will also switch boost from 7 - 10 psi depending on a number of factors, I found mine could never make up its mind and kept dropping down to 7 all the time even after I got all the engine lights off and changed the stat to stop the extra cold running (old stat opened at 60 degrees and boost will drop off if water temp is under 80 ish).

The dash gauge is crap, get a different boost gauge and see if its doing the same, if it is then find the fault or fit an MBC, the latter is what I did after 18 months of trying! Only set to 10 though so safe enough to do.

[BenF]

Make sure you're running Super Unleaded - sounds like the ECU closing the VSV beacuse air temps are below 4C, or it has picked up some detonation.

[Marf]

High intake temps will also cause the ECU to limit boost.