J9BBY

I have switchable high / low boost on my car. Works fine on low boost (8psi), but when switched to high boost it boosts to only 14psi (stage 3) and coughs and splutters. Changed to a bleed valve and boosted up no problem, so thought it must be the amal valve. Got a new one and has made no difference.

Any suggestions????? HELP PLEASE!



Cheers,
Pete.

frog

I'd check the actuator, could be a little weak and unable to hold the extra boost pressure.

Also, check your boost hoses (air intake, turbo to i/c and i/c to throttle body), see if they are squishy. When the turbo draws air in, if the hose isn't strong enough it can collapse, leading to an insufficient air supply.

Fuelling (pump, pump electrical supply, filter, injectors) and plugs would be the next thing I'd check. As boost goes up, you need more fuel and a strong spark

Hope this helps.

tabetha

Just put a group a coil on it.
£32 delivered, MATT LEWIS 01922 692424.
Use a 0.6mm plug gap also, with decent leads like MAGNECOR.
tabetha
check your phase and cps gap at same time, though they will not be the cause

J9BBY

Cheers for that. HAve ordered up some new plugs and a group a coil and i'll take it from there.

Everything else has been checked or replaced - petrol and ignition side.

A trip to a rolling road might be in order if that doesn't cure the problem.

Thanks again.




Pete.

J9BBY

Changed coil and plugs and no difference, so put bleed valve on, bypassing the amal valve altogether. Now boosts up fine with no stutters etc.

What could this be? A fault in the ECU?

Amal valve has also just been changed.


Any suggestions gratefully received!


Pete.