No overboost?

[dest]

Running a homefry ecu (currently has the loan one fitted), I am only ever seeing 15-18psi on my gauge.
I have tried all the tests in 4th gear and above on WOT at 2k to the red line, and when it comes on boost it averages 16psi and holds it steady.

Now, I have just been out and given it WOT in 2nd gear, and got the same thing: came onto boost, went to 16psi and held it steady until I changed up.

[QuattroFever]

I think thats the norm with a homefry IIRC. Overboost is gone just all round higher boost level.

[newsh]

1 Bar spring and WGFV disconnected?

[dest]

I should of also said that before the homefry was fitted, the symtoms were all exactly the same apart from it making 10psi.
So the homefry has gained it 5-6psi

[QuattroFever]

ah.

[S2central.net]

@dest - you have an air leak - pure and simple.

OR -------> another common fault in that your throttle body is not physically opening far enough cos of kakked throttle cable install... or that the throttle pot is not registering the right resistance at WOT to tell the ECU that your right foot is on the carpet. Try the TPS tests on S2central.net.

OR ----> A faulty altitude sensor that is lying to your ECU... It can't be your MAP sensor inside the ECU as you have tried two ECUs at least.

The homefries essentially delete the 'overboost' mode - such is the pernickety way that the ECU decides on whether you get into that mode or not... So essentially the max boost profile is the same as overboost profile... On full load you'll get full boost.

So in the mid range you should be seeing 1.4bar (20-21psi) dropping off to about 0.8bar on the redline.

I promise you - there is an air leak or Motronic sensor fault that is telling it not to apply full beans - boy are you in for a grin when that is fixed

[nip]

i see 20-23 psi on homefries

[dest]

Ok, Ill give those ideas a try.
I guess it has to be a very small leak as its still holding 15psi strong (will be checking vacuum hoses)

I really do hope it transforms the car, as so far its still feeling slower than my old Cav Turbo (280bhp) by a fair margin!

[dest]

Try the TPS tests on S2central.net.

Any chance of a direct link?
Im damned if I can find it

[newsh]

http://www.s2central.net/ds_F60_G69.html

[newsh]

Dest, get someone to sit in the car and push the accellerator pedal all the way down, look under the bonnet and see if you can open the throttle any more, if you can then take up the slack on the adjuster.

[dest]

Just checked the throttle, it is opening as far as it can

I had a quick look round the easily accessable (not many LOL) vacuum hoses, and two looked abit ropey, so replaced both with silicon ones:
Rear of manifold to pink line and front of manifold to the link tube.

Didnt make any difference though!

I will be replacing them all eventually anyway, hopefully sometime next week if I get time....

[S2central.net]

Does your car have aircon ?

If so - check extra carefully all those narrow hoses at rear of engine - one of the check valves has a hidden pipe that was loose on my car for ages and gave boost reduction woes.

Oh and check the pipe that goes from front of IM down to the bypass valve - both braided sections of that are prone to friction induced leaks.

Keep the faith - its something stupid.

If the plan to get over to the mainland works out for later this month, I'll be happy to help try and locate the fault - but no promises here - some of these niggles can take a while to track down.

Paul

[dest]

Ive not got aircon, thankfully!

I replaced the short section of the pipe from IM to DV, will do the other end later in the week when I get time.
I have grabbed a copy of the vacuum tree on s2central, so will work through it all and replace everything soon as I can (will need to get some more hose first to do it all :mischeif: )

I will definitly take up your offer to have a look if you are able to, hopefully it will be sorted by then though!
Even if it is, Id be up for popping over to Az's to say hello etc

[S2central.net]

Did you change BOTH braided sections from IM to DV ?

Theres a metal tube behind the cam pulley that links them... Top tip (if you don'thave MItyVac) is to pull the tube off at the IM and suck on the hose with your gob - if it doesn't hold vacuum then something is wrong.

What about the WG diaphragm ? Checked it ? YOu can use same suck tactic with a length of hose attached to the port on the WG cap - it must be airtight.

Paul