Boost issues

[Kingsford G]

As above having a boost issues with my car.It wouldn`t boost above about 7-8psi and last night it boosted to about 14-15psi and today again underboost to 7-8psi and trigs an emission light and reads p0172 system too rich bank1.The car is V70R pre me7 awd,its not mapped and runs on TCV.The elbow vacuum pipe as many stated is the reason is fine.I didn`t have much time to look at it and hopefully tomorrow have some time to spend so before I start some tips would be helpful.

[Jamest5r]

Lamda??

[smithy]

Maf

[Kingsford G]

Lamda??

Had a 2nd hand good one fitted from 2.5t so not 100% sure it is lambda.I wonder if a nackered TCV can cause that sort of problems?

[T5RatherAmusin]

how boost is controlled....
revs climb, boost pressure developes.
ecu reads maf, throttle position and rpm to read boost pressure...
once boost pressure is calculated the ecu will activate the bcs wich will control the actuator wich controls boost.

faulty, these are what would mainly cause boost issue
hope this helps ;)

my bets on your maf btw

[T5frankie]

better break it then mate :uglyhamme

[Kingsford G]

how boost is controlled....
revs climb, boost pressure developes.
ecu reads maf, throttle position and rpm to read boost pressure...
once boost pressure is calculated the ecu will activate the bcs wich will control the actuator wich controls boost.

faulty, these are what would mainly cause boost issue
hope this helps ;)

my bets on your maf btw

Have a working MAF fitted too with no joy,will try an mbc to c what happens.Must be a vacuum leak somewhere.I had a MAF problems before where the car would run like crap and stall,this time it runs fine.

[Kingsford G]

better break it then mate :uglyhamme

I`ll wait till u brake yr auto mate and have some bits of u lol Spent too much to go back in fact more than I paid for it.

[T5frankie]

I`ll wait till u brake yr auto mate and have some bits of u lol Spent too much to go back in fact more than I paid for it.

not gonna break that beauty lol, its running sweet, very slow though compared to a manual

[Kingsford G]

not gonna break that beauty lol, its running sweet, very slow though compared to a manual

Can`t take yr word for it so I`ll wait lol Mine is manual and slower than yrs lol

[Kingsford G]

Just connected an mbc which was set up to 15 psi and she boosting fine.Frankie I'll race yr snail 70r now lol

[T5frankie]

Just connected an mbc which was set up to 15 psi and she boosting fine.Frankie I'll race yr snail 70r now lol

Lol it ain't that slow at least it's mapped lol

[Kingsford G]

Lol it ain't that slow at least it's mapped lol

Hold onto it mate,awd is good for yr mrss

[smithy]

Bcs is nackered then leave the mbc on its more fun lol.

[Kingsford G]

Bcs is nackered then leave the mbc on its more fun lol.

Have to be careful with my heavy foot tho,don`t wanna be frankie 2 lol

[M-R-P]

it'll only be a bit tappy...

give it some...

[Kingsford G]

it'll only be a bit tappy...

give it some...

Can`t trust a cheap mbc`s much mate.I`m on the hunt for a mapped ecu.

[M-R-P]

Can`t trust a cheap mbc`s much mate.I`m on the hunt for a mapped ecu.

Big girls blouse, I've had a cheap MBC (£5) on mine for several months now with no real problems ;)

[BoostWagon]

same here, dodgy mbc, as long as your gauge is accurate you will be fine ;)

[M-R-P]

same here, dodgy mbc, as long as your gauge is accurate you will be fine ;)

Dude, that's not your biggest problem, the welded diff however... ;)