Hi i have just done an efi conversion on my S2. when i start to boost i can here the turbo coming in but gets to about 3000 - 3500 rpm goes flate sort of holds back so i back off the accelerater and i get a chatter from some where think its iver the damp valve or exhaust maybe both? i have tryed 2 turbos on it and it makes no change? iam thinking vacuum pipe or the pipe that goes from the housing straight to the achurater (waste gate)

 

was thinking to day the inlet's efi and the waste gate set up for mfi (t3 turbo of an s2 mfi) so could the vacuum pressure be different on mfi and efi so the waste gate could be opening and closing at the wronge time? coz i think they could be adjusted?

 

Harry my ol' fruit, what's the boost gaguge reading?

Did you set the preload on the actuator before you fitted it?

Are you running an amal valve?

Lee

 

no and no, running a pipe straight from turbo housing to waste gate with a bit in the middle of the pipe to keep the boost down? dont no how to pre-load waste gate?

 

to preload the actuator simply adjust the length of the shaft mate.
an ideal starting point is knownn as a halfmoon preload.
adjust length of actuator rod so that you have to stretch it to fit over the wastegate arm.
the hole on the actuator rod and the wastegate shaft should meet up half moon style,roughly 3mm preload.
im crap at explaining things,does that make sense lol?????

 

What is this bit:

Do you have a boost gauge? It would be useful to know how much boost is there and the characteristics of it (e.g. peaks at 10psi then drops to hold 8psi).

It sounds like there's little boost and the rest is being wasted off. I'm guessing as you can hear the turbo it must be quite loud.

There must be some boost there as the "chatter" is the sound of the pressurised air between the closed throttle butterfly and the turbo escaping back past the turbine inside the Turbo thats spinning in the opposite direction.

Check the boost level and then adjust the preload as neccesary would be my first advice mate.

Lee

 

yer ill give that a go, got a boost gauge in the car iv got a felling its about 5 psi i wasn't really looking. ill let you non how i get on over the weekend


the bit in the middle is like a washer hose connector it about 2-3mm smaller in diameter that the vacuum pipe tuning place put it in for me because my old AMAL valve was boosting high

 

an ideal starting point is knownn as a halfmoon preload.


cheers ill try looking up on youtube see how you do it i'm certain thats got to be what causing problem!!

 

A standard ERST should hold 8psi, take that reducer out and just put a pipe from the turbo housing to the actuator. If the preload is set right then this should give you 8psi

Lee

 

ofac or ofab?

 

so i worked on it over the weekend done the half-moon pre-load which did need adjusting, removed my dump valve took it for a spin and its still the same!!

but it is boosting 10 psi? but when i am driving under load it dont wanna know,but put the clutch down and it revs free nice but when its under load and the turbo starts to kick in it feels like its being restricted sort of like a boost cut off valve? almost sounds like its misfiring and just wont rev out of it? also seems to be smoking a bit i am sure it aint engine or turbo i am thinking crank case pressure i am sure they are linked?

so i'm thinking maybe MAP sensors shiting itself on positive pressure and it isn't fueling right? ive put the map sensor on its side when i fitted it could that do it?
also when idling its a bit lumpy and if i cut pressure to the map sensor it idles really nice

or maybe another sensor? the only other ones i'm not sure on is the speed sensor i haven't got one on at the moment ive read you dont need it on and people by pass them but by, by pass do thay mean unplug or pin it out?

i no its a lot to take in but any ideas or thoughts on what ive put would be helpful

 

Nakered actuator ?

 

sorry took long to reply mate think you got problem wit your map sensor i had the same issue, also your car maybe self learning my=ine did this drove shit for the first 5 miles make sure ure map, act sensor is ofac or ofab depending on what ypu got