[Mk2] [Generic] Low Boost

[Morgan]

Hi all,

I'm a new member and was hoping one of you might be able to offer some advice. I have removed a manual boost controller from my car and the boost now seems low, is only making 0.6 bar, before the manual boost controller was fitted, some 3 years ago, it was making 0.9 bar.

I am not sure exactly what is wrong, is turbo bu88ered?, no smoke, car pulls strongly.

Any advice would be welcome.

Cheers

Morgan

[Tubby]

welcome along dude,in what gears do you get that psi?

[toxo]

Sounds like it had the factory boost control removed to fit the manual boost controller, and now that you've removed the manual controller it has no boost control at all so is running on actuator pressure.

Check your T-VIS underneath your inlet manifold is connected properly.

However what your factory boost level is depends on how old your car is.

[Morgan]

Cheers Tubby

That was quick,...

2nd gear, it might touch 0.7 in 3rd 4th

[Morgan]

Factory boost controller wasn't removed, I installed the controller myself, have re-enabled vsv valve

Cheers

M

[toxo]

How old's the car?

[Morgan]

1994 rev 3, 125,000 miles, most of them by me on the motorway. removed the boost controller to try to preserve the engine, turbo was changed at 60,000

[toxo]

So about 10/11psi and you should be seeing ~14psi.

It is exceptionally cold at the moment, the ECU does chop boost levels down in this weather as you get the same volume of O2 into the car with lower pressure levels.

[Morgan]

Yes I guess it is cold, but has been low for a while.

[RobCrezz]

With the VSV connected i think if the abient temp is below 5'C it goes into low boost mode.

[Morgan]

Guys, so in short, your assessment is that the turbo isn't broken and that in some way, either temp or I haven't re-enabled the VSV properly the boost is being retarted.

Just to be clear, boost should be around 0.9 bar standard?

I do have another question,....If you disable the VSV, is the ECU still able to protect the engine??

Cheers

M

[jimGTS]

Guys, so in short, your assessment is that the turbo isn't broken and that in some way, either temp or I haven't re-enabled the VSV properly the boost is being retarted.

Just to be clear, boost should be around 0.9 bar standard?

I do have another question,....If you disable the VSV, is the ECU still able to protect the engine??

Cheers

M

0.9bar is stock on rev3+, with tvsv hooked up.
ecu would protect the engine in different ways, in safe mode it already lowers boost down to actutor pressure, which is the same as bypassing the tvsv = run on actuator pressure.

[Morgan]

Cheers,

Nice machine by the way.

M

[RobCrezz]

Guys, so in short, your assessment is that the turbo isn't broken and that in some way, either temp or I haven't re-enabled the VSV properly the boost is being retarted.

Just to be clear, boost should be around 0.9 bar standard?

I do have another question,....If you disable the VSV, is the ECU still able to protect the engine??

Cheers

M

Why did you take the boost controller off?

[Morgan]

Just concerned about the stress on the engine, has alot of miles on it.

Question is,...where can I take it, in or around Bristol to get it fixed?

Cheers

M

[Quigonjay]

I do have another question,....If you disable the VSV, is the ECU still able to protect the engine??

in a way
with it enabled, the boost is restricted in 1st and 2nd and/or if the outside temp is below 4 or 5 degrees so if you disable it the ecu has no control over these saftety measures and as said you will be runing on actuator pressure (same as me switching off my electronic boost controller, i then run on actuator pressure)
not 100% on this but i beleive with the vsv disabled and no other form of boost control, the only way the ecu can protect the engine is if it detects knock and retards the ignition

[toxo]

+ fuel cut if you overboost.

[Morgan]

So chaps, where can I take it to fix it, i'm in bristol?

Thanks for your help

M