Not making full BOOST!!

Hi Guys, my first time here. Not sure where i should post this.................

Recently purchased a 2005 Legacy B4 JDM. Been having issues making boost.

Everytime i reset the ECU the car makes a little over 1 bar of boost and then i here a ping and it go's into Limp mode which will not pass 1/2 a bar of boost. While driving you feel that the care wants to make more power but its being restricted. Anyone encountered a similar issue?

Swapped the MAF sensor, MAP sensor checked the CAT for airflow restriction but nothing works except resetting the ECU. Then as soon as i make full boost. The car pings and "LIMP MODE" again and it will not pass 1/2 a bar of boost.

Any help will be greatly appreciated.

Welcome and I am not sure this is the cause but have you checked to see if you have a vacuum leak anywhere? I could see how this could cause something like that

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Your car is sending you a message and ignoring it and resetting the ECU is a good way of blowing something up permanently. Stop resetting the ECU. See if you have any CEL codes. Get your hands on a tactrix/vagcom cable, and pull a LearningView and log.

Audible pinging sounds great

Why don't you try boost leak testing/looking for leaks first? Pinging sounds great for your motor

Originally Posted by iNVAR

Your car is sending you a message and ignoring it and resetting the ECU is a good way of blowing something up permanently. Stop resetting the ECU. See if you have any CEL codes. Get your hands on a tactrix/vagcom cable, and pull a LearningView and log.

Thanks guys,
fuel pressure is ok, there is no boost leak noted and also i have no check engine light. We did a log and noticed a knock when it made peak boost. Going to reflash the ECU and hope for the best.

Originally Posted by Mohen

Thanks guys,
fuel pressure is ok, there is no boost leak noted and also i have no check engine light. We did a log and noticed a knock when it made peak boost. Going to reflash the ECU and hope for the best.

By flashing the ecu it's the same thing as resetting it and if now you are hearing a knock when you make full boost there is clearly sonething wrong vacuum wise or internally, you can destroy the motor continuing to drive the car like that.

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Also make sure your running the right gas as stupid as that sounds that could be the problem, what octane are you using?

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Originally Posted by lgtvf52

Also make sure your running the right gas as stupid as that sounds that could be the problem, what octane are you using?

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Good point. Many of the JDM models require 100RON fuel.

Thanks, i live on the Caribbean island of Dominica and the gas we get is similar to 92-93 octane.
By flashing the ECU we hope we will to be able to adjust the fuel map and have a lil bit less aggressive timing. Any other thoughts or comments are appreciated.

Originally Posted by Mohen

Thanks, i live on the Caribbean island of Dominica and the gas we get is similar to 92-93 octane.
By flashing the ECU we hope we will to be able to adjust the fuel map and have a lil bit less aggressive timing. Any other thoughts or comments are appreciated.

Instead of reflashing you could just try to manually retard the timing. Becareful doing that though because a little to slow can (and most likely will) cause a late ignition which can cause a knock.

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Originally Posted by lgtvf52

Instead of reflashing you could just try to manually retard the timing.

How are you able to 'manually retard timing' without modifying or reflashing the ROM?