False boost reading?

[ChrisLdn]

Have been reading all the low boost topics but can't seem to solve my issue.

I am seeing a maximum of 0.4 bar boost on the dash. The car feels fast but I have nothing to compare it to as it's always been like this since I bought the car a few months ago.

I got silicone hoses fitted and billet forge DVs. I got the garage to check out for any issues. They couldn't find anything after fitting the parts and claim it is as fast as it should be. They tried a new sensor and it made no difference to the boost reading. I don't know if to believe them.

I today reset the ecu by disconnecting the battery. The car feels a bit more responsive but boost remains at 0.4.

Is it possible I have a false reading? Can it be fixed? I don't want to leave it if I am not getting full boost.

Any ideas of what to check next or how to tell if it's boosting right?

[Sunnyside]

A few things that worry me are;

Why hasn't the workshop put an external boost gauge on the car and taken the car for a test drive to prove boost is correct or not.

&

0.4 bar of boost is a significant figure. That's what the boost would be if the DME goes into limp mode and pulls boost.

If your workshop come back and tell you boost is low on an external boost gauge, I would want a boost leak test doing.

what does Durametric say your boost is?

Frank.

Edited October 20, 2011 by Sunnyside

[ChrisLdn]

Hi Frank,

The garage didn't pop a gauge on for the testing but said it would be the next step. I suppose I need a more turbo fluent garage than this independent. They did change the actuators so that's another thing off the list.

I don't have a durametric but might look to purchase one.

I have read that the 0.4bar is significant for the limp mode. But how do I get out of that? Is a durametric the only way? The battery reset did not work.

[ChrisLdn]

Booked it in to JZM for diagnosis. Will report back. Low boost sounds like a common problem with many potential causes. I very much doubt its a false reading.

[Sunnyside]

Hi Frank,

The garage didn't pop a gauge on for the testing but said it would be the next step. I suppose I need a more turbo fluent garage than this independent. They did change the actuators so that's another thing off the list.

I don't have a durametric but might look to purchase one.

I have read that the 0.4bar is significant for the limp mode. But how do I get out of that? Is a durametric the only way? The battery reset did not work.

Battery reset normally fails when there is a hard fault causing limp mode to be continuous . The other reason for the apparent not resetting after battery disconnection is of course that the DME isn't in limp mode to start with. you might have a big boost leak, so no matter how much resetting you do will never resolve the problem.

1st port of call should be codes followed by a boost leak test.

Hope you get the problem resolved, I look forward reading about your results .

:thumbup:

[ChrisLdn]

Just got the call from JZM. They have sorted it in a morning, amazing service from these guys, seriously impressed.

It was the 3 way valve and electric motor thing for £16! I think is the 'N75' valve I have read about? Also the repaired actuators I had done before and the waste gate calibration was off. Now boosting 0.8 -0.9. They really know their stuff.

So a couple of little bits and 2 hours labour. Looking forward to driving it. I thought it was fast before.

[Sunnyside]

Just got the call from JZM. They have sorted it in a morning, amazing service from these guys, seriously impressed.

It was the 3 way valve and electric motor thing for £16! I think is the 'N75' valve I have read about? Also the repaired actuators I had done before and the waste gate calibration was off. Now boosting 0.8 -0.9. They really know their stuff.

So a couple of little bits and 2 hours labour. Looking forward to driving it. I thought it was fast before.

Brilliant result & please for you.

:clapping:

[phillipj]

Excellent! I love happy endings.. ^:jump:

[ChrisLdn]

Thanks guys.

Just picked it up and am very happy with it. It's boosting to 1.0bar! So guess it's had a little remap in its past. Any idea what hp it is likely to be? Probably 450+?

Was thinking of getting one in the future so am a happy bunny. Perhaps that's why the other garage didn't notice the lack of performance at 0.4, it was quick anyway.

Can't recommend JZ Machtech enough, think I am going to use them for servicing now too. Washed and hoovered! Nice touch.