boost drops under load

[sparkus2]

got a wee prob with beeza fitted my own version of k04 a few months ago and has been going great and is still apart from noticed im loosing boost under load.was running 1.1,1.2 bar and holding at that but since last week noticed only getting 0.9 then it slowly drops t 0.7 and holds there but car still pulls like a train so got to be boost leak ive had all pipes of and looked cant find any holes in pipes!also thought it could n75j valve so took it off and put on mbc which i had on before set at 1.2 bar and still the same prob even tried diff boost gage with new piping still the same.one thing i noticed is that the actuator dosent feel that strong compared to old one on k03 and when you rev the car a bit the actuator moves straight away so i think this maybe my prob or could it be somethig else?anyone else had similar probs any suggestions would be great.

 

[cordobabrendy]

have a nosey at recent posts mentioning the actuator, someone mentioned similar and to test for iffy early venting. cant help much more sorry, but the searchy function should give you some sort of help.

 

[sparkus2]

cheers had a look couldnt find much on it.might just try other actuator of old k03 see what happens just means taking of manifold again.could the dump valve cuase this sort of prob to?

 

[cordobabrendy]

what model of valve are you using?
if its standard plastic bosch crap, get a better one,
if its a forge 006/007 try the leakdown test, its listed here also somewhere (remove valve and create a seal on the top hole and press the valve upwards inside then see if the valve drops back down, this will show if its leaking through from the top)

 

[sparkus2]

just got the crap one at the mo waiting to get milltek diverter valve ill try get hold of a new tt225 one to see if that helps.

 

[cordobabrendy]

tt225 ones are the same plastic crap mate, buy a forge 007p itll do exactly what you need and servicing kits are buck shee if you talk to forge nicely on here!!

 

[sparkus2]

the tt one is just to see if it cures my prob car was boosting fine with the crappy one up until last week just arrowing things down.

 

[Simon L]

Plugged it into VAGCOM and found the error?

I randomly hit "negative boost deviation", and on really cold days i hit "postivie boost deviation".

 

[h17och]

any news on this as i seem to peak at 21psi then slowly drop to 10-11psi!

help needed guy

thanks in advance

HoocH

 

[Simon L]

On a K03 you should only be seeing 10psi need the redline at most. The small turbo is maxed out.

 

[h17och]

its a ko3s and it drops to 10psi around 5,000

I dont think it used to!

HoocH

 

[Simon L]

Never noticed you had a K03S. You should be making more than 205bhp!

Get VAGCOM on there and see what your N75 duty cycle is, i bet its 95% through the range. Youve probably got a boost leak.

 

[h17och]

the rolling road i go on seems to come out around 20bhp all the time!?!

went on there on sat and i only got 240lbft, 197 bhp!!!????
and i have revo stage 2 since the 205bhp and 183lbft read out???

so somethings gone wrong!

smelt a little of cat on the rollers, would that reduce the boost?

got a new n75 last month!!

couldnt hear a boost leak on the rollers!!

cheers for your helps guys

HoocH

 

[Martyn]

Guys, log blocks 002,115,118 with vag-com and post the results. 4th gear runs if possible.

 

[h17och]

What will that tell us martyn? not got Vag-com so will have to wait untill Vagtech can do it for me! probaly wednesday!

cheers

HoocH

 

[Simon L]

That will show us your actual vs requested boost, and your maf values.

 

[Martyn]

Hooch, it'll tell me 3 things...

Block 002 - MAF Values...Is the MAF showing correct values?

Block 115 - Boost.....(Actual Vs Requested) Is it meeting requested?

Block 118 - N75 Duty.....If 115 doesnt look good then block 118 will help show up a boost leak or a fault N75

After logging those i'd like to see Block 020 too which is the timing correction...

 

[h17och]

Cool, Cheers martyn, your a dude

Will try to sort them out for so you can av a look for me!

Wouldnt i have heard a boost leak on the rolling road?

Has a new maf (few weeks old) new n75 (few weeks old) no that it means thay are ok tho Bloody VAG silly little problems are soo annoying!!

HoocH

 

[Martyn]

No probs dude, let me know when you've got 'em and i'll have a looky looky. Where are ya based by the way?

I doubt you'd of heard the leak bud, RR's arent exactly quiet

I feel your pain...I came from an Integra Type R which was a dream to run....no bloody complex ECU trying to tell me when and what I can and can't do with my car!

 

[h17och]

Same boat

CRX del sol VTI

Honda's are a dream

HoocH