[Mk2] [Turbo] boost problem @ 4k-4.5k rpm

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Leon.
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Joined: Fri Jan 07, 2005 7:35 pm
Location: Guildford, Surrey

Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by Leon. »

suprmanmr2 wrote:So the ebc is out except for the wires coming from the ecu to the unit. Would that cause any disturbance if the unit is messed up?


You'd be best to at least disconnect the power supply to the headunit, then you know it can't be controlling anything.

Have you also connected T-VSV back up and everything to make it 100% stock? (Not sure if that would make any difference but maybe best to account for everything...)

I'd then reset the ECU, but before do a diagnostic test again incase a code has now had time to develop since the last reset. Sometimes better to disconnect the -ve terminal of the battery to reset to be 100% its worked...
suprmanmr2
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Location: London
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Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by suprmanmr2 »

After a long day in Harprnden where i left my car fron 7:30 to 4p.m. at Pan Auto there diagnostic result was: " Seems like air leak from the intercooler"

The guy there said there could be a small hole in the intercooler which is causing boost to build up only after 4k rpm.

What would be your suggestion?

Would a hole or leak from the intercooler cause the boost to come on late?

The EBC is completely out including the headunit. However later i did connect the headunit back in showing how much boost was being made.

WOT in 3rd gear I hit 0.78 bar boost.

On the way back the car really had its moments. Funnily it seemed slightly better than before but just had its own mood when to kick the boost in.

On occasions i got boost kickin in at 3300 rpmish and on others it stuck to 4k rpm?

Would you think its got to do with air leak in the intercooler? which causes these symptoms?

Secondly my water temp gauge goes all the way down to cold while on the motorway. I topped up with coolant a few days ago. I have replace the thermostat a few weeks ago during service. My temp gauge rises when stationay to half point.

Is that got anything to do with the intercooler?

Thanks guys,

Sorry for this long essay.
stig
Posts: 88
Joined: Thu Sep 15, 2005 7:05 pm

Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by stig »

Just as a daft question, you said you stopped at tesco (for fuel too?)

what fuel are you using?
c33k4y

Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by c33k4y »

have you sorted your problem yet?

I was at the 'ring last week. towards the end of my 18th lap i noticed my car was only running on 4-5psi! I can hear the turbo spins but only little boost.
When i got back I found the hose that connect from IC to hotpipe(where BOV sits) had a 2 inch split at the bottom of the hose!!

with an air leak from IC you will lose boost and should still be able to hear your turbo spins!!

would a faulty wastegate/actuator cause this problem?
Loser
Posts: 70
Joined: Thu Jun 26, 2008 9:22 am
Location: Stoke-on-Trent

Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by Loser »

I've got a sticky wastegate after a decat fitment too, a cheap gay ebay one, i'd never heard of this wastegate clearence issue before.

I have a VERY similar problem to this, with all your boost control kit out take your car to the very top of its rev range in 3rd or so, then lift and just wait. This ends up shutting my wastegate and everything is hunkey dorey (until i make the WG open again :roll: )

*goes off to search about wastegate clearence*
Razor04
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Joined: Mon Jun 09, 2008 4:25 pm

Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by Razor04 »

Throttle position sensor?
Leon.
Posts: 12780
Joined: Fri Jan 07, 2005 7:35 pm
Location: Guildford, Surrey

Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by Leon. »

Loser wrote:I've got a sticky wastegate after a decat fitment too, a cheap gay ebay one, i'd never heard of this wastegate clearence issue before.


Its been reported a couple of times.

Cantfindausername wrote a how to on sorting out the wastegate clearance issues on eBay cr@p, try a search...
mattcambs
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Joined: Thu Jul 13, 2006 9:59 pm
Location: Saffron Walden, Essex

Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by mattcambs »

suprmanmr2 wrote:
Secondly my water temp gauge goes all the way down to cold while on the motorway. I topped up with coolant a few days ago. I have replace the thermostat a few weeks ago during service. My temp gauge rises when stationay to half point.

Is that got anything to do with the intercooler?

Thanks guys,

Sorry for this long essay.



I'm no bloody expert, but, DUDE :shock: Sounds like the new thermostat isn't working! Once the coolant is up to temp the needle should stay at just below half way regardless of conditions.

Your ECU (which on Rev2s is pretty tempremental compared to rev3s anyway) thinks the engine is still getting up to temperature and is running the "start-up" map. With the TVSV connected (i.e stock boost control) boost is limited when the engine is cold and I also think the fuelling will be richer and the ignition retarded? [can experts confirm], however your EBC is keeping the actuator closed to make the correct boost even though the ECU is trying to limit the load on the engine because it thinks it hasn't warmed up yet.

I've either hit the nail on the head or just written a load of wine induced cobblers :lol:

:D :thumleft:
Loser
Posts: 70
Joined: Thu Jun 26, 2008 9:22 am
Location: Stoke-on-Trent

Re: [Mk2] [Turbo] boost problem @ 4k-4.5k rpm

Post by Loser »

Well i did the test from the manual (you should have seen the creation i made to do so, bike pump, lots of random hosing and a dodgy vacuum tester (im a cowboy baabaayy!)) and it seemed to work fine, fully open it'd always shut.. Sprayed a nice amount of spray greases down there (and all over my driveway :evil: ), let that work its way in (opening and closing the WG) and it's not stuck once since, its only been 3 days, but it's been a hard 3 days :mrgreen:


Crazy temp gauge.. Could it be possible that the gauge is finding some air? I know on honda's reading air makes the temp gauge bang straight up into the red, but i think its possible for the temp gauge to read zero if there's no coolent around it.. Does that make sense??

Did you bleed the coolent? Ala manuel?
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