hmmyip

Ok settle in, this could be a long story...........

When I bought the car last October, it seemed to be very quick (I had moved from a 306 gti6 to an my98 terzo), but was overboosting quite badly.

So, as described on here, I cleaned out the Boost solenoid, reset the ECU and hey presto fixed overboost problem. But, it did feel slower, I put this down to me getting use to the extra power and thought nothing of it.

Got speaking to MickWRX (Nice graphics!) at the NBO and he said that he has no probs running 1 bar with a dawes device, but said that I must get a boost gauge before I thought about doing anything.

This I knew to be sound advice and so at the NBO I bought a nice greddy boost gauge, which I fitted that evening.

Left the car as it was till today, so as to monitor what it was doing without a MBC fitted. Car has full decat and induction and forge dump valve, but seems to be standard everywhere else.

I had read on here that normal boost pressure was meant to be 0.9 bar, so was a bit surprised when all I have been seeing was 0.5 - 0.6. Now I have fitted a MBC and can only get it to rise to 0.7 (with the controller nearly screwed out!), so figure there must be something wrong.

I have read to check the wastegate/actuator and its clip,as the turbo will only boost to 0.5 bar if anything faulty with it, but I have no idea what to check ie where is the clip and how can you check a wastegate?

Is there anything else I should be checking?

I have reset it all back to normal for now as I dont wanna blow the engine.

Any help would be greatly appreciated.

Cheers

Jonny

94impreza

My 94WRX is pretty standard, was running 0.7 bar now runs 0.8 after fitting a Z4 ECU no Decat as yet. What i would say is i covered my thin pipe running from the T-Piece up to the boost gauge with a thicker pipe to stop it snagging/pinching and to clean it up a bit. I noticed a drop in pressure, so investgated. I could hear a hissing and located it to the now slightly thicker piping. After a few plays and turns of the jubilee clip the hissing (obviously pressure escaping) the boost returned to normal.
I would suggest running the car up and listening for any hissing to suggest lack of pressure. As for a boost control valve, i bought one a while back, fitted it and thought "whats the point" you'll always want max boost available so I ditched it.

RedScoob

Is your car very noisey on boost? I had a similar problem with low boost and found an airleak under the intercooler.
The only other thing I can think of is that the car may be in "limp home" mode due to overboosting. If you do an ECU reset and look for error codes from the CEL that should indicate if anything's wrong.

hmmyip

Cheers all, now sorted it.

Think it was a comination of, originally a faulty boost control solenoid, then a blocked Dawes.

I discovered everything was fine due to a hose that had found its way onto the lambda sensor and then melted, which led to massive 1.2 bar boost then I backed off realising something was wrong, but obviously capable of boosting that high.

So have today fitted an in car boost controller and replaced the offending pipe and can hold 1 bar quite happily now.

Thanks again to all.

Jonny