boost holding back

[floppy_dave]

right then, i decided to clean my engine bay before i start going through every sensor as i have a problem.......

when i bought the car the boost was running at 1 bar and now it seems to have reverted to 0.6 bar, sometimes itll revert back then sometimes it wont............

so i thought i would go though the sensors i can reach and see if that helps. so i cleaned it, took it for a run and good as gold it ran full boost and the idle was running normal ie: 900 rpm.

so what i need to know is have any of you had a similar experience and if so where do i start ? and or what os the problem?

cars running:

Jam sprt ECU
Profec B boost control
K&N filter
Fujitsubo exhaust and de cat

cheers in advance, dave

 

[damien4uuk]

Had the same, turned out to be the the plug that conects to the air box sensor, was really loose so i tightend the conection clips and now works well.

 

[floppy_dave]

right ill try that then tomorow, just had the boost controller out to check for leaks and there arent any, its also stand alone so the boost isnt controlled by the ECU in any way... am i getting there ?....? we will see :roll:

 

[Tart]

Are you sure its not spending a lot of time running in safe mode.... have you done a fault code check???

 

[floppy_dave]

nope, not sure... how would i do that >? would sound about right tho ?

 

[Tart]

Theres a sticky note wiv all the instructions at the top of the problems section. check it out. a fault code check will take 2 mins to do...... might save you lots of investigation time.....

 

[Crazy]

Definatley sounds like its going into 'SAFE' mode, but another thing which had me puzzled for a week or two was the Greddy Boost controller.

Which one is it because I have recently found out that the Greddy Profec B Spec 2 will limit boost to 10psi (0.6-0.7bar) until you touch any of the buttons on the controller, then it will run the whatever boost it is set up to run

Hope that makes some sense

 

[floppy_dave]

right, well im still confused.... :?: ive done a fault check and its showing 55, which in one repect is a good thing but still means i havent found my problem! :evil:

im running a spec 1 profec B <the manual one with two dials [low and high]> so i think the next port of call is to have that out and send it away for testing, unless anyone else has any ideas?

thanks for the help so far guys

 

[Tart]

OK but have you done the test with the fault. with mine when she was running fine I had 55 but then the det code fault comes up when I have the problem.....

 

[floppy_dave]

tried it immediately before and immediatly after the fault test and it ran at a restricetd boost of 0.6 bar so that seems consistent.

 

[Fast Guy]

tried it immediately before and immediatly after the fault test and it ran at a restricetd boost of 0.6 bar so that seems consistent.

When you say 0.6bar are you getting this off a boost gauge reading in bar or the standard gauge reading 6 (mmHG) some people confuse the standard gauge, 6 on the standard gauge would be standard boost allowing for a slight inaccuracy.

 

[floppy_dave]

no its a secondry boost guage, theres a very definate difference between the restricetd 0.6 then the two stage of the greddy, which is 0.75 and 1.0

 

[floppy_dave]

anyone with any more ideas or am i gonna have to pay someone?

 

[geetee]

Is the standard boost controller still plumbed in?

Sounds like safe mode which is triggered by the det sensor picking up detonation. This does not show as a fault code on the ecu check procedure. Only if the ecu detects the det sensor is either not connected or sending nonsense readings will you get a fault code.

If the standard boost controller is not still plumbed in, safe mode would only retard your ignition timing as the ecu has no control over boost levels without the standard solenoid. That said if the ignition is retarded you may not be able to make more boost anyway.

Has it always done this or only recently?

CHeers
GeeTee 8)

 

[floppy_dave]

hi there,

theres nothing original about the boost it has all been disconnected now and re plumbed into the standalone greddy unit. its done it since i bought the car unfortunately but its ran for 3months / 6k without too many other problems.

think a garage os the answer i rekon the boost controller os duff myself as i cant see how the ecu could restrist the boost as it isnt connected in anyway, we will see :twisted: