V40 T4 loosing boost in 3rd and 4th gear

[Ginga]

Originally Posted by 960kg

When you turn that actuator arm in it has to be done in complete turns as it also wears on a slight angle so although you think you have ajusted it 2 turns it may only be 1 1/2 turns!

Then as Baffler says it can jam as it is on an angle and may dig in rather than pull cleanly.

Mine was worn quite a bit where the arrow points and unless really hot to expand the gap it would start to leak.

Oh, see what you mean. Mine has some play there. up and down... 1mm maybe?
I suppose this isn't exactly serviceable.....

[Ginga]

Looks like it's not a consistent issue. Yesterday it didn't show any boost loss in those gears.

[960kg]

The small pin for the actuator arm on my `98 T4 was no where near as worn as yours but as said the larger pin that goes into the wastegate was worn with terrible side movement...up and down doesn`t matter...

Maybe you could even have burning of the flapper door inside the wastegate that closes and could leak due to carbon on it or a piece broken near the edge where it seals?

The boost loss does sound mechanical if inconsistent like mine was also.

[Ginga]

Just to keep this thread up to date, already changed my fuel pump.

For a start, the engine is running much stronger past 4000rpm. Sweet!
Didn't get to check on the Fuel Trims. It's possible that the LTFT is now lower (and still positive).

About the boost drop, looking back I realised that it happened on my first runs after reconnecting the battery.
Maybe it's the BCS re-learning its stuff?

[960kg]

Originally Posted by Ginga

Just to keep this thread up to date, already changed my fuel pump.

For a start, the engine is running much stronger past 4000rpm. Sweet!
Didn't get to check on the Fuel Trims. It's possible that the LTFT is now lower (and still positive).

About the boost drop, looking back I realised that it happened on my first runs after reconnecting the battery.
Maybe it's the BCS re-learning its stuff?

I am pleased you are getting somewhere and the motor is running better...

As you have proved yourself just by replacing one or two plug leads the power goes to a different rev. range and the engine responds gladly.

The Ph1 T4 pre 2000 is a very different animal to the later 2 litre Ford T4 and has to be treated differently to get the best from it......by saying treating differently i mean ALL genuine Volvo parts should be used even the air filter as all is good for 250bhp ...if you want more noise remove the foam in the box only!

I even had proper 4mm Volvo boost pipes which are very strong and do not squash under vacuum like the silicon ones do. This can make the boost guage flutter as the silicon pipes move and not give consistent boost....which is why i changed them.

Make sure you get the proper BCS as they differ and give different readings to boost and revs.

You can`t buy cheap with the `98 T4 as it simply will not respond to what you want.....although money can be a problem with some just buy once and fit once and get the best performance for quite a few years with reliability to suit!

[Ginga]

Already done the 'foam treatment'. Actually thought it would get louder.
Just ear more turbo, building boost and releasing it through the revirculation valve.

[960kg]

Originally Posted by Ginga

Already done the 'foam treatment'. Actually thought it would get louder.
Just ear more turbo, building boost and releasing it through the revirculation valve.

Just a tip: from std. you can go 5 full turns on the actuator rod and it will give you 19.6psi / 1.35bar which you can use for evermore but the mpg can suffer down to 28mpg @80mph

Don`t go 6 turns which is max. as it doesn`t run so smoothly!!

You will notice that as you have removed the foam and you can hear the turbo spooling even as low as 35mph in 4th if you keep it under that you will get more economy but of course no enjoyment....lol

[Ginga]

For now I'll keep it with 2 turns/1.1bar.

It's averaging 10l/100km = 28.2mpg doing mainly motorway with 3 people and luggage to the roof @ 80-100 mph.

It's running good that way, with plenty throttle response at low speed/city traffic and enough grunt to keep the speed when climbing!

Really happy with it!

[V40T4R]

Fuel pressure regulator at the injectors rail is advisable to replace also.