problems with overboosting k10

[dave007]

hi guys
dave here justed joined tonight great to be here
i drive a 1990 march superturbo ive had her for more than a year when it came from japan the turbo gone with not boost coming from it so i had it replaced with a new one but on the first test drive the car overboost within seconds from that day to this i have changed the turbo hoses/vac hose/plug leads/supercharger/inter cooler/the valve that opens and closes between sc and turbo/
if i disconnect the switch on the sc and just drive on turbo everty thing is fi
ne but for the turbo lag
any help on this problem would great

 

[Ed]

Need to be more specific, stick a boost gauge on it and then let me know exactly from where to where it over boosts. Shame you cant bring the car to me as I would probably know pretty fast whats up!

 

[dave007]

at about 1800rpm its boosting 0.9 and the car will not acc until you take your foot off the acc petal and it will do it in any gear my brother has a micra as well but when his gets to 0.7 the needle dnt go any further

 

[Ed]

ok, you need to start with the vacume piepwork for the supercharger. Something is wrong somewhere, either that or your bypass control valve needs looking at.

 

[dave007]

i removed the my brothers one and tried that with no change i have a boost gauge myself is there somewhere on the sc side i can check for boost pressure or do you know what boost is ment to be there

 

[Ed]

The boost pressure should be 700mmhg, approx 0.9ish bar. The boost bypass valve (the smalle one by the washer jet) controls the limit, the bypass control valve is under the intercooler that may have got stuck or a problem with something relating to that.

 

[dave007]

thanks for that info ed i check that sat and let you know how i get on ta

 

[Turtle]

Welcome, from a normal micra owner

 

[Arnold]

Welcome to the club. Your most is more technical than an intro so its been moved to the correct section.

Cheers
Arnold

 

[Baz]

i removed the my brothers one and tried that with no change i have a boost gauge myself is there somewhere on the sc side i can check for boost pressure or do you know what boost is ment to be there

Alryt man where in Ireland you from.I live in dublin
I'd say some of your vaccuum hoses are in the wrong place

Here's the diagram

 

[martycturbo!]

more st,s in ireland!!!! good stuff