The classical 30FF turbocharger charge air pressure too low..any ideas?

pbondar

Sergeant
May 30, 2020
418
238
0
Background…

Major upgrade..TTE500 turbos, 535 LPFP, VSRF inlets and charge pipe, decat down pipes, Fox cross over and exhausts, VTT turbo outlets, Forge DVs, Wagner 7.5” FMIC..stock air back with Pipercross filter, NGK stage 1 colder 22 thou, Index 12 injectors..

All was going so well, a few hundred miles, several runs on the dyno circa 20 psi boost 500 BHP , 680 nm torque on 98 Ron fuel..chasing a misfire on cylinder no 6 at 6,200 ish…

Tuner asked to change plugs n coils to check if that affected misfire on cyl 6, swapped 1 and 6 coils and fitted colder NGK at 22 thou..went out no change, strong pull with 1 out of 6 with cylinder 6 misfires.

Tuner asked for cylinder 6 injector to be checked..duly checked..no observable issues, fresh seal and decoupler fitted..

Went out and before reaching the ‘pull zone’ bong and the half dead engine symbol lit up..a code check showed the 30FF code..

I went ahead and did the pulls..

So here’s some earlier logs with no errors apart from the oEd misfire on cylinder 6 at 6k rpm…


and here are the logs with boost impaired..


So it’s getting some boost around 6 psi not 21 psi..

I started to do some vacuum tests which showed a leakage fault on the rear boost controller ..I swapped it out for a new Pierburg..no change.

I took it to my tame Indy / dyno guys..they confirm no obvious loose connections anywhere in the inlets, turbos, intercooler and charge pipe..

So it’s work in progress due to availability of people and resources..I realise that we’ve not done a fully comprehensive set of tests..

Any views on where to look would be appreciated…so no error on start up or under modest throttle…which I understands tends to preclude boost leaks..

RSVP
 

wheela

Lieutenant
Jun 4, 2021
1,089
602
0
Twin Cities, MN
Ride
2015 e84 X1 35i Msport
So it’s getting some boost around 6 psi not 21 psi..

I started to do some vacuum tests which showed a leakage fault on the rear boost controller ..I swapped it out for a new Pierburg..no change.

I took it to my tame Indy / dyno guys..they confirm no obvious loose connections anywhere in the inlets, turbos, intercooler and charge pipe..
Did they do an actual boost leak or smoke test, or just a visual of the connections?
 

pbondar

Sergeant
May 30, 2020
418
238
0
Did they do an actual boost leak or smoke test, or just a visual of the connections?
So far just a physical examination..as I said due to time constraints a full exam has yet to take place..the question is why does a N54 perform very well..then drive a further 5 miles at modest speed..go into my garage for a few days while I remove and reinstall an injector then after that 5 miles later gently driven develop this fault ?
 

pbondar

Sergeant
May 30, 2020
418
238
0
Well boys and girls having gone down the vacuum testing route and found a rear boost controller that was leaking I thought I’d solved matters…sadly no..

Following advice here and frustration with Indy’s inability to troubleshoot the issue ordered a leakage kit..

Within 10 seconds of using it found the issue…

The hose connecting the rear and front turbo outlet pipes (VTT) had popped off the front aluminium pipe…turns out the Indy who fitted it had not put enough rubber on the front outlet so it had just slipped off..

Of course it was hidden by a heat shield hence why we didn’t ‘see’ it earlier…

Clamps fitted from underneath so couldn’t get to release the clamp that was working…

Dremels are wonderful things..

Cut the remosimg tight clamp off…rotated hose to get the front clamp…found a spare wider clamp in my goody box…refitted..

Waiting for some fresh heat shield wrap then will test..got to be an improvement..
 

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Torgus

Brigadier General
Nov 6, 2016
2,671
2,193
0
Boston
Ride
ACF 6466 E92 + METH
Always nice having to troubleshoot and then fix someone else's mistake. Glad you got it fixed. The pressure leak test is useful to have on hand for anyone.

If it does not stay on I would use the hairspray trick, replace the silicone coupler, and switch to murray clamps.
 
  • Agree
Reactions: SLOWESTN54

pbondar

Sergeant
May 30, 2020
418
238
0
Always nice having to troubleshoot and then fix someone else's mistake. Glad you got it fixed. The pressure leak test is useful to have on hand for anyone.

If it does not stay on I would use the hairspray trick, replace the silicone coupler, and switch to murray clamps.
It’s another example of tackling the unknown…once you‘ve done it for the first time you wonder why you ever dithered..👌
 
  • Agree
Reactions: Torgus