Overboost?!

[Rich]

Okay, this has been asked before but I will ask it again. Does anybody know how to fix the overboost function on the Delta HF Turbo ie? I know that the overboost valve works, but the car ain't overboosting and please don't tell me about after market floormats! - I tried that one and it still doesn't work.

Help please.

Rich

[Janne]

I`m not realy understand your problem,is the turbo presure to high or to low?or das the engin bakfire.
Please wright me a letter and tell me more, has 20 years work in Turbo engins.
Janne.

[Janne]

You may have the problem in the overboost solenoid valve,its a electronic pressure reduser switch,the standard pressure reduce is 0,7,if it is higher than o,7 the computerbox should reduse the pressure.The valve is connected with the waste-gate valve actuator,and the Turbo charger,if the reduser fail you can get big problems,it also can be a connect problem in the reduser or the computerbox.(the connect pinn nr in the box is 16.)
Good luck with your car.
Janne.

[Alan Cooper]

The most obvious reason for this is that due to a very heavy right foot over the years the actual pedal has distorted hence overboost or full throttle are never achieved try bending the pedal with a bit of brute force and see what happens.....or alternatively get someone to look under the bonnet while you push the pedal to check that the throttle does open fully

[Rich]

Thanks for the responses guys but I have sorted the problem - there is a small cylindrical plunger located where the throttle mechanism reaches full throttle and it was seized so absolute full throttle could not be achieved, hence overboost isn't activated - I have been told that this is quite a common cause for the overboost not working - now it is sorted!!

Rich

[Danny]

I've had the same problem ever since I've had my car! Where exactly is the cylinder you are talking about? I've tried all sorts to get the overboost light to come on. The solenoid switch works and the car boosts ok. Thanks.

[Rich]

Okay,

Open the bonnet, grap the throttle mechansim and push it to full throttle (with the engine off!). You will notice the throttle mechanism cannot go any further at full throttle because it taps against a small metal cylinder on the front end of the air box (the bit behind the two cams with a 'T' on it) - it doesn't look like it is meant to move but it does with a bit of WD40 and some assistance it will plunge down - free it up and the throttle can move that bit further to activate the overboost! Quite a novelty once it works but I must say the boost doesn't go as high when
you have the overboost looped! (joining the two pipes that meet the overboost valve) - quite subtle but nice!

Good luck

Rich

[Danny]

Rich
thanks it worked a treat its taken me 3 years and just about everything else people have suggested to get that to work, i was supprised what a difference it makes!! thanks again.

[Rich]

No problem mate, glad it works, isn't a good feeling to get that light come on and feel the extra boost!

[nelson rocha]

i would like to know if lancia delta HF turbo of 1990 have overbooster.
I have the indication that exists but thbe pressure dont´pass 6,5 bar
i see the others replays about the overbooster but i can see anthing about it.
please say that may HF have overbooster!!!:)
thanks .
Nelson Rocha
Portugal