Spyder550

Hi I am trying to find out why I am getting no boost. The gauge I have measures vacuum and boost and I am seeing the vacuum at idle but when I rev to about 4K it boost does not generate boost, perhaps up to 0.5-1 psi.

The intercooler and pipework appears to be fine, I can't find any air leaks there. This is a install of a 94 WRX motor into a kit/replica so am using non standard intercooler.

Guessing it may be a dodgy recirculation valve, or 3 port boost solenoid , but is there anything else that may affect boost not being generated. As it stands I am still to drive the car on the road so am carrying out the checks on a stationary vehicle. I assume the gearbox neutral switch signal or the VSS signal does not limit boost when stationary.

satancom

Is the wastegare on the turbo closing properly? The circlip my have come off allowing the wastgate to flap about and relase all boost pressure!

Spyder550

OK on that one when I looked

satancom

If you Ling the turbo wastgate dirrectly to the turbo outlet with a piece of vacume hose, by-passing the boost solenoid completely.. You should boost to about 0.6 bar. This will eliminate the wategate and related pipework.

It will also narrow down the components to look at (boost solenoid manily)

Funnily enough i have one for sale on ebay at the moment

I had a problem with my wastegate leaking under boost, after a quick adjustment its fine again!

mark6

what sympton would leaking wastegate show?would it overboost?i currently have a problem and i'm currently trying to get all info possible,sorry not trying to hi-jack thread,just struggling to get info in my thread.

johnnyroper

try blanking off the recirc valve and see if that helps.
also check the clip is holding the wastegate actuator rod on to the turbo still.
to eliminate/prove 3 port solenoid connect vac hose directly from compressor housing nipple to the wastegate actuator you should boost to 0.6-0.7 bar.

i doubt it is a boost leak as it would probably black smoke or not run as the fuelling for amount of air going past maf would be way out.

johnnyroper

no a leaking wastegate would not cause overboost.

a leak at wastegate would reduce the amount turbo can spool so boost would be low

Spyder550

Cheers for the replies guys, will take a look at the boost solenoid and recirc valve at the weekend. The circlip was on the arm as far I recall, remember it was on a week ago anyway and the problem has existed longer than that, but I only fitted a silencer at the weekend, too many blips on a 3" open downpipe won't make me too popular with the neighbours

Is there anything on the Neutral switch or VSS side of things that would limit boost when stationary. Also the ECU may not have been cleared down via a ECU reset proceedure, I normally leave the battery disconnected for now though

scoobybrad

I know this sounds silly but have u driven it about cos u said bout not gettin boost when stanionary, u will onl get positive boost when the its under load and revving it when at a stand still will not do this?

Area 52 Autosport

That's the one, you won't generate boost when stationary, it's load related so you won't see it boosting until you drive it.