Was out in the car today,put my foot down,hit full boost,then just cut out,as if i took my foot of the floor.It was a smooth cut,not mis-firing.
carried on driving around,all seemed fine,thought i would try it again,this time watching afr,boost gauge.
the boost gauge went off the dial(30psi),thats whats making me think its over boost protection.
Anyway arrived home and had a look around,and found the hose that comes from the turbo to the amal valve,was loose on the jubilee clip,therefore letting pressure out.
Is this a normal effect of over boost protection,or could i have another intermitent fault,its a msd 380 chip
thanks all
Matt

 

I could be wrong, but I don't think aftermarket chips have boost protection on them?

 

i reckon the ,msd ones will have

 

It can't have a boost cut as they run 32psi and your map sensor cannot read that high.

 

ah,any ideas what would cause it to cut out ?

 

Depends on how high the boost was, if it saw 50 psi i would expect ign and fuel miss fires,

 

was a very smooth cut,as if you gently took your foot off.
what sensors should i start changing in order,also where can i buy a new tps and amal valve.
Its typical,taking the car on a roadtrip to marbella in 4 weeks time

 

Sounds like TPS symptoms to me!?

 

just connected the air compressor to the inlet of the amal valve,and it bleeds straight through,is this correct,
would connecting 12v to it close the valve and open the wastegate.it closes when i hold my finger on the "r" of the amal valve

 

so in effect it makes the amal valve redundant,

 

this is one of the things I don't like and would never do again, needs to run below 2 bar of boost with cut at 2 bar or have a 4 bar map sensor fitted, its not worth the risk imo.

 

No the Amal will still work the boost cut would cut the ign and put you through the windscreen lol.

Check you actually have internals in your Amal valve as the map is flat out as far as boost control goes so many people remove the guts and just jet the valve like a manual bleeder

 

cheers ,will have a look tomorrow,

 

amal valve all intact,put a new one on anyway.
should the amal valve be energised when the engine is ticking over,at the moment there is no voltage,although it does click when the ignition is switched on

 

Yes, it should have power with the engine running, it's controlled via PWM and when a boost threshold is met or high ACT's etc it is directed to the actuator.

Martin

 

update

put a known working wastgate on,and dissconnected the pressure pipe to it.(so should get full boost regardless of amal etc..)

Still no joy,hits 20psi,then just drops of to 0,no pops,no bangs,its just like you take you foot of the floor,(but its still there)then just drives normal again.
Changed map sensor,act sensor,nothing,and now its pissing down,

Any more ideas

 

If the turbo only makes 20psi with the actuator pipe off, either the turbo is dead or you have a big air leak.

 

deff no air leak,the turbo is practically brand new

its not holding at 20psi,its like you turn the ignition of,it dies

would the Iaw monitor be of any use,would it flag up any faults

 

UPDATE

right,hit does hit full boost with the actuator disconnected(it was wet hen i was trying it before,and wheel spinning).
The amal valve clicks on,then off when the ignition is switched on.Should it do this,or should it stay on.what controls the amal valve
this thing is driving me nuts

 

It has a switched supply via the fuel pump relay, this is the reason why it clicks twice, i.e. on and off and will coincide with the prime duration.

When the car is running it will have a constant feed, the ground is controlled by PWM and as I say the it closes under certain conditions, with the pressure going to the actuator.

Martin

 

thanks for the info martin
been trying to set the tps,when i set the closed position to around 0.35v,the car idles perfect,when you rev it,the amal valve remains OFF,(not energised).
When i set the tps to say:- .8 volts,at idle,i get a higher voltage reading fully open.around 5v.The car idles at about 2500rpm,but then when i rev it,the amal valve energises.
Its as if i cant get full open movement of the tps when i set it to .35 volts,

Do you know of a link ,where i can look at a wiring diagram with the colours on
Cheers
Matt

 

Great reference site here

http://www.bigturbo.co.uk

 

cheers rob,had a look,but need the colour codes on

The reason its a pain in the arse,i have to take off the elbow each time i adjust the tps:-

 

Well after hours of time spent,turned out to be a worn throttle linkage