Still got a ****** Boost Leak

[Dr H]

Got the car back together today, replaced the hoses with Samcos, replaced all vacuum tubing with silicone stuff, used all new jubilee clips and also replaced the 8mm hose on the turbo and wastegate.

Took the car out and..............................still has exactly the same characteristics .

Boosts up to about 1.4 bar and then trails off. By the time I'm doing 4000rpm it can be below 1 bar. Always gets to 1.4 bar but the always trails off.

What the fook is happening .Any suggestions before I take a match to it

[Lee]

My remapped K24 peaks at around 1.4 bar then tails off as the revs rise falling to below 1 bar at redline. The K24 won't take much more and this boost profile is deliberate to avoid breaking the turbo. What boost profile do you have and what do you expect? It may help diagnostics.

[Dr H]

My remapped K24 peaks at around 1.4 bar then tails off as the revs rise falling to below 1 bar at redline. The K24 won't take much more and this boost profile is deliberate to avoid breaking the turbo. What boost profile do you have and what do you expect? It may help diagnostics.

I'm running a homefry that has never been right from day one. As soon as the boost was inccreased the car started acting like it had a leak.

In stock trim it did exactly what it was supposed to. I went to 1.1 bar on overboost and sat there until maybe 5,500 - 6000 rpm or the 15 second time limit.

Since remapping it always reaches peak boost (1.4 bar) but never keeps it in the way it used to. By 3500-4000 rpm the boost can be as low as 0.9 bar. Surely that's not right.

I juat can't see where it is leaking from as I've changed everything. I'm having trouble with one of my breather pipes (see other post) but I'm begining to wonder if it is the ECU backing off the boost.

I always get to peak boost, surley it wouldn't do this if it was leaking. Absolutely nothing has changed since I replaced all the pipes, the car acts in exactly the same way

I'm ****** pissed off

[Lee]

If your boost profile is normal and you are losing power you may have a fueling problem: injectors or filter?

Paul N should be able to confirm what boost is normal at different rev sites under load for your chipset.

[Lee]

Check you MAF and log Lambda if you can. You can do the latter with a multimeter to check mixtures.

[newsh]

Have you pressure tested it? If you can pump it up to 1 Bar then you will hear it if its leaking.
At the garage meet with the tester and airline we found we had leaks on hose clips that were done up really tight, had to grease the threads of the jubilee clips to stop it.

[newsh]

Another thought.
Its just possible that its leaking inside the ECU..

[Dr H]

Had a new lambda about 6000 miles ago and was fine until the chip was done.

Had the fuel filter done since the chip no different.

Clean the MAF and no difference. Tried APNEss's MAF and still no difference. Does show an error which related to the MAF and airflow which also points to a leak

Had it pressure tested at Gregs garage meet and it seems to be loosing a little but nothing obvious - Tom suggested that it will loose some through the turbo seals when pressure testing like this.

[APNess]

Had a new lambda about 6000 miles ago and was fine until the chip was done.

Had the fuel filter done since the chip no different.

Clean the MAF and no difference. Tried APNEss's MAF and still no difference. Does show an error which related to the MAF and airflow which also points to a leak

Had it pressure tested at Gregs garage meet and it seems to be loosing a little but nothing obvious - Tom suggested that it will loose some through the turbo seals when pressure testing like this.

Arggh.

I feel for you mate. I had EXACTLY the same symptoms, as you know, but putting the RS2 intercooler on cured them for me, so I suspect a leak was somewhere around the intercooler at the time. *shrug* Any apparent damage to the intercooler, or the pipe behind it that feeds the inlet, even a small hole? I've seen the intercooler at Gregs and didn't look like any dents at first glance, but I'm clutching at straws here - assuming the home fry is fine (and should be as other people running identical stuff with no bother?) there must still be a leak somewhere...? Unless the ecu is retarding boost because the inlet temps are too high (is that how it works with overboost?)

Other than that, maybe someone has a home fried ECU in the north of England for a plug in and try?

"When everything else has been ruled out, whatever remains, however implausible it may be, must be the truth."

Guess Sherlock Holmes never tried to find a boost leak on an S2...

[s2avant]

I'm in the same boat as you Leigh. I'm currently gathering every possible intake part that hasn't been changed to replace. I've even got hold of some ABA robust agricultural hose clamps to hold the hoses in place. Once the last couple of bits arrive it's coming to pieces and all being changed.

I don't know enough about how the overboost protection routine is triggered but I'm wondering which sensors are used to determine if there is a problem. If one of the sensors is playing up this could cause the protection routine to kick in.

Ben

[horvathg]

I'm in the same boat as you Leigh. I'm currently gathering every possible intake part that hasn't been changed to replace. I've even got hold of some ABA robust agricultural hose clamps to hold the hoses in place. Once the last couple of bits arrive it's coming to pieces and all being changed.

I don't know enough about how the overboost protection routine is triggered but I'm wondering which sensors are used to determine if there is a problem. If one of the sensors is playing up this could cause the protection routine to kick in.

Ben

Forgive my ignorence but if Sherlock Holmes never searched for his boost leak, where did he take his S2 to repair the leaks? Anyway, I dont recall reading any of his posts on this forum. Is there another S2 forum in England?

[Sidspud]

Other than that, maybe someone has a home fried ECU in the north of England for a plug in and try?

Can you get to the Manchester meet? If so, you can borrow my ECU to test it. Not sure of an exact date yet but its either the 13th or 20th of June.

[Doug_RS2]

Try turning the diverter round the other way. Has it been replaced?

Has the wastgate been tested? Has it been fiddled with? Try disconnecting the WGFV and see what boost levels it runs.

Disconnect the boost hose in the engine bay that goes to the ECU and use a mityvac tool to presurise it to 1.4 Bar - see if this(mityvac) matches the boost pressure on your boost gauge.

Change your Fuel Filter (hahahaha) - it is easy on a coupe!

[Lee]

Change your Fuel Filter (hahahaha) - it is easy on a coupe!

I have a way of changing it without dropping the tank on the avant , it works too.

[Dr H]

Try turning the diverter round the other way. Has it been replaced?

Has the wastgate been tested? Has it been fiddled with? Try disconnecting the WGFV and see what boost levels it runs.

Disconnect the boost hose in the engine bay that goes to the ECU and use a mityvac tool to presurise it to 1.4 Bar - see if this(mityvac) matches the boost pressure on your boost gauge.

Change your Fuel Filter (hahahaha) - it is easy on a coupe!

Diverter has been replaced and it was put in the same way round as it came out. Never gave any problems in stock trim this way round. Should I change it round?

New WGFV and the diagphram was tested with a mityvac (at Gregs). How do I disconnect the WGFV? Which hose and do I need to plug anything up?

Not got a mityvac to test the boost guage but in stock trim it used to read just about 1.1 bar on overboost, so I'm guessing it is OK

Changed the fuel filter a couple of thousand miles ago and it made no difference

ECU with new version of homefrys (mine is a version 1) on its way from Mr N as we speak (hopefully).