Help Low Boost!!!!

Had a simular problem with my 91 RS - I almost got draged off by a late model honda prelude. In my case it occured after playing with the engine management computer, i didn't attact one of the connectors to the computer properly. (silver- grey box with yellow connectors located driver's side above right of the accelerator peddel) so check this first. When my RS boosts above 5psi I hear a denstintive relay 'click'. This controlles the wastegate (which controlles the boost) From what i can remember the wastegate is actuated by boost pressure, & in its 'unmanaged' state the wastegate will open at 5psi The ECU prevents the waste gate opening by using a solenoid valve prevent boost pressure getting to the waste gate (simular to a boost controller does which you by from any car parts shop like Repco) The solenoids natrual state is open so if it fails it doesn't result in overboosting -so check this. swap it with a mates is the easest way. It is attached to a thick vaccuum hose that runs from the manofild or just infront of the turbo to the valve and then wastegate (or the other way aroud) and air intake resonator Also check the relay switch mentioned above, sorry not sure where that is. The turbo legacies (early naturally asperated legacys arn't) are also fitted with a pressure sensor that could be the problem, but it is unlikely. if you find that it is the solenoid valve and IF they are are expensive, you might concider getting a boost controller instead (mentioned above), it will do the same job for around NZ$90, and you can turn up the boost. Caution: Don't boost your early legacys above 14psi, The formentioned pressure sensor stops working somewhere between 14-15 psi, after that the ECU ha no idea how much boost you are putting in and goes mad and sprays as much fuel as it can, making for a rich mixture, and loss of power. Plus it tends to f***K your engine.

Mike

Here is a unrecommended side note, as mentioned aboe the waste gate on the (legacy) turbocharger will open at 5 psi, without ECU intervention and since most cars (non-turbo) ECU fuel maps are programmed to operate upto 6psi of pressure you could conceivably bolt on a small (automatic GT) turbo to any legay/impressa/forester with only purchasing relativly non-expensive items.

"Luke Gallagher" wrote in message news: snipped-for-privacy@radsrv1.tranzpeer.net...

Hi,

i just brought a cheap bost gauge (from repco) for $30NZD, my cars not that flash, so i didn't see the point in a flash gauge. Yeah i connected it into one of the intake mainfold lines & it had no influence on how the car ran, but at least its told me i need to look at getting more boost! I will probably add a boost controller if I cannot fix the factory stuff.

Luke