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Problem with boost only 0.5 BAR sometimes

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Old 08 October 2015 | 11:22 PM
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Default Problem with boost only 0.5 BAR sometimes

hi
i need any help, advice... Car Blob WRX 2005 PPP. sometimes (around one time in 3 week) i have problem with boost, looks like ECU switch to "safety mode" and charging only 0.5 BAR, normaly at PPP i have 1.3 BAR. Today this is happened again, after around 20mils my travel (last 10miles in London trafic) everything was fine, but some idiot hard braking and to avoid emergency stop i just past him, reduct to 2nd gear, push accelerator pedal, around 5k RPM i shiht 3rd gear and i think thats happened this time. I remember before (4 week ago) i just drive on motorway, easy, not hard. When this problem occurs i scan ECU but not show any fault code, i need restart ECU (disconnect +) and after 5 min reconnect, after this all work fine. I use only Shell V Power, BP Ultimate petrol, so i think its some sensor ? but i dont know, i have no idea how check this problem...

Thanks
Old 08 October 2015 | 11:49 PM
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Any other mods to the car? Do you have a boost gauge? 1.3 sounds high to me for only PPP, I thought that was 1.1?

I'd stay off the bp fuel too, scoobs don't seem to run well on it.

Last edited by fatboy_coach; 08 October 2015 at 11:50 PM.
Old 09 October 2015 | 06:41 AM
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Mine won't make boost until the engine has warmed up. Has the car had enough time to warm up when you encounter this issue?

I did have an issue after using bp fuel where I couldn't make boost but I changed the Ebay dump valve the previous owner had fitted back to the recirc valve and problem was solved once the engine warmed up I was straight back on 1 bar of boost even with the bp fuel.

Other people will know better then me but if I recall things to check are boost pipes, sticky dump valve, if dump valve fitted is the recirc hose blocked properly, where is the cut for your boost gauge to be connected? Is this all connected securely (one hose kept popping off of a T piece on mine). Also could possibly be the car isn't getting enough fuel so possible fuel filter or fuel pump. Oh and clean the boost solenoid. Maybe even maf sensor.

Last edited by LoganS; 09 October 2015 at 06:43 AM.
Old 11 October 2015 | 12:12 AM
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hi
thanks for any helps. fatboy_coach i have boos gauge, Depo racing, + bluetooth OBDII and i check on my smartphone, and both show same. about 1.3 BAR this is right for PPP Blob '05, i check with subaru and i have info from prodrive UK so 1.2-1.3 its OK.

I think BP Ultimate is very good, same as Shell Vpower, but i try use now only Shell and we see. Maybe i should check fuel filter because its wosent change from long time... Its must be something easy because no any fault code in ECU.

Thanks anyway
Old 11 October 2015 | 04:40 PM
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have you check all the clamps on the intercooler fittings are tight as if not this can limit boost
Old 11 October 2015 | 04:57 PM
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Originally Posted by danprec
hi
thanks for any helps. fatboy_coach i have boos gauge, Depo racing, + bluetooth OBDII and i check on my smartphone, and both show same. about 1.3 BAR this is right for PPP Blob '05, i check with subaru and i have info from prodrive UK so 1.2-1.3 its OK.

I think BP Ultimate is very good, same as Shell Vpower, but i try use now only Shell and we see. Maybe i should check fuel filter because its wosent change from long time... Its must be something easy because no any fault code in ECU.

Thanks anyway
I've heard BP ultimate fuel been called plenty of things but never VERY GOOD
Old 12 October 2015 | 08:19 PM
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Originally Posted by danprec
hi
thanks for any helps. fatboy_coach i have boos gauge, Depo racing, + bluetooth OBDII and i check on my smartphone, and both show same. about 1.3 BAR this is right for PPP Blob '05, i check with subaru and i have info from prodrive UK so 1.2-1.3 its OK.

I think BP Ultimate is very good, same as Shell Vpower, but i try use now only Shell and we see. Maybe i should check fuel filter because its wosent change from long time... Its must be something easy because no any fault code in ECU.

Thanks anyway
Fair enough on the boost, but the fuel isn't in the same as V-Power/Tesco99, hopefully a few tanks of either of those and an ECU reset will see your boost return

Here's Duncans take on it: http://www.racedynamix.co.uk/remap/f...ke-difference/
Old 12 October 2015 | 09:23 PM
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Thanks for help, so thats happened for me because last 10-12 tank i do on BP because my Shell local was close to renewal, but now is open so i prefer tank Shell now again i i see. Thanks
Old 12 October 2015 | 09:27 PM
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Is the car maybe going into limp mode.
Old 12 October 2015 | 09:32 PM
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Originally Posted by johned
Is the car maybe going into limp mode.
How i can check it ?
Old 12 October 2015 | 10:21 PM
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afaik just taking the +off the battery for 5 mins won't perform an ECU reset.
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