L555BAT

THINK I MAY HAVE TO MUCH BOOST WHEN I FLOOR MY CAR WITH OUT DROPPING A COG IT STARTS TO PULL A WAY LIKE **** OFF A SHOVEL THEN STOPS PULLING FOR A SPLIT SECOND AND ITS LIKE HIT IN THE BRAKES WHEN IT DOES THEN IT PICKS UP AGAIN AND THROWS YOU BACK IN THE SEAT SOMEONE SAID IT MAY BE TOO MUCH BOOST IF IT IS CAN I CURE THIS BY ADJUSTING THE ROD ON THE ACTUATOR OR NOT
I THINK IT MIGHT BE RUNNING ABOUT 16psi OF BOOST IS THAT TOO MUCH ?
THE CAR IS A MY97 AND HAS A RDA CHIP I THINK AND A FULL MONGOOSE SYSTEM AS WELL HAS A FITTER UP GRADE

COULD IT BE BECAUSE I HAVE NOT BEEN USEING SUPER UNLEADED?

HELP ME PLEASE OLLY

MrData

Hi

I had similar symptoms on my Volvo T4. It pulled like a train and was real fun to drive at the time.

I took it to the Volvo garage and a pipe had come loose from the Turbo. It happened again and they fixed it again.

Then the turbo blew at 59750 miles. They replaced it under warranty.

The pipe fell off again and having been told "It won't do the car any real harm" I left it a week or too before I got it fixed.

About 3 months later, when the car had finally gone beyond it's warranty, my new 3 month old turbo packed up again.

I have to hand it to "Bells Volvo - Northampton" that they were very fair. Even though the car was out of warranty, they felt it should not have gone and gave me 50% discount off a new Turbo.

The pipe never fell off again and the car did another 40,000 trouble free miles before we sold it.

The moral of the story - get it fixed pronto before it blows itself to bits.

Regards
Kurt

Neil Smalley

Check out the drivetrain forum, look for the key words 'overboost'

L555BAT

CANT SERCH FOR KEYWORD OVERBOOST SURCH NOT WORKING IS MY PROBLEM OVER BOOST

Neil Smalley

sounds like it. You'll have to browse manually A restictor usually solves the problem. I can't remember much more, sorry.

Check http://www.scoobynet.co.uk/bbs/threa...threadid=78895

AndrewW

and try turning your caps lock off, you're sending us all deaf

Its the big key over there on the left.

Andrew.

L555BAT

sorry

AndrewW

nae bother mate.

wasn't trying to tell you off, just to educate

Its generally considered bad form to yell in your posts.

There is a restrictor in the boost pipework that determines the point that the boost will go to. By changing the size of the restrictor you can limit the boost and stop the overboost from happening. I've suffered from this myself and it sucks big time.

Take it to a dealer if its still under warranty, otherwise get a good independant scooby specialist (scoobysport if they're close to you) to have a look at it.

It won't do any long term damage (thats why the overboost cutoff is there in the first place) but its bloody dangerous when you pull out to overtake

Thanks,

Andrew.

CallumW

Is it possible you are have a fuel starvation problem.

It sounds like the pump can't supply enough fuel. If you are running lean, then this will boost power greatly, but will lead to eventual engine detonation

It sounds like when you give it welly the fuel runs so lean the car hesitate as if it has run out of petrol, then gets a piston full and is off again.

Put it on a Rolling Road and get them to give it the once over.
(cheaper than a new engine and a steam clean)

Callum

L555BAT

were abouts is the restrcter and how can i change it the problem seems to be geting more offten need to fix it now is there some thing i can disconect to stop it

CallumW

You could always disconnect the big red wire to your battery...that'd stop it.


Never mind...back to CS

L555BAT

funny enoth i have tryed that to reset the ecu but didnt work

Tim Bomford

Re-fit your standard airfilter for the time being. That will stop the overboost until you can get a restrictor.

Tim

Mo

What is an RDA chip?

Firstly, you must use SUL as a minimum unless your car has been specificaly mapped to run on NUL.

You state that you think the boost may be at 16psi? Do you have a boost gauge to confirm this? If not get one fitted sharpish. I would presume that all the RDA chip has done is raise the boost in a similar fashion to a Superchip. Has the fuelling and ignition been altered accordingly?

The decat exhaust will be the most likely cause of overboost, what with this and the raised boost I would be concerned. Get it onto a rolling road and get it checked out ASAP.

pob on the job

The restrictor is in the small (vacuum like) line between the turbo delivery and wastegate actuator. You'll easily be able to feel it if you squeeze all the tubing. Some cars have a coloured dot right where the restrictor is in the line. The orifice is very small and adjustments of .1mm in restrictor size can make a substantial difference. Also, where the restrictor is fitted in the line may also make a difference. Try moving it further away from the turbo, nearer the wastegate and see if that helps any. It does sound like overboost/ fuel cut.
Failing that, get a different sized restrictor.


Alan

L555BAT

sorry chip is a rtd i think or some thing like that i have cured the problem by lentaning the actuator rod but why did it sudenly start to over boost

Darren Thompson

It started to over boost due to the cooler air being denser, also the restrictor is a small brass olive in one of the 3 small rubber pipes going to and from the actuator as I had the same problem on my full Prodrive MY98. My car was then running 1.5 bar and we moved it down to 1.2 bar by using a P1 restrictor.

Do a rolling road day and get it set-up correctly, could save you a lot of money in the long run.

Daz.