Stage 3 turbo inlets leak effects

[f4m0u5]

On my recently built stage 3 car (2 months 2k miles) I started to get a lean code and thrown into limp mode. P1130 p1128 ( part throttle to lean). Ltft for idle are -1.4 and -1.8 and part throttle are +17,+18. And this is with driving around normally without boosting even 1 psi.


According to my logs before on wastegate pressure and same rpm I was geting around 30-40 g/s more then I am now at wot. Wich made me think of a leak after maf before throttle body . But since boost was holding steady still and under wot my a/f are lean now (12.5 when before where 10s at 14 psi) instead of richer like it would be if I had a boost leak. So has to be between turbos and maf?

Long story short I ended up doing boost leak test and at around 5 psi my driver side inlet starts hissing. If I move it around by hand (it doesn't realy move but puts pressure in different directions) the pitch of sound changes.



Is a leak on a inlet at 5psi pressure realy a problem under light suction from the turbos ( like I said codes come up without turbos boosting just staying in vac cruising) so it shouldnt be that strong of suction in the inlet if I'm not in boost..

I went up to 12 psi and cant find any other leaks that's the only one.

[Zba]

There is more air entering the system post maf so yes, even your inlet leak is bad. Ultimately just seal it up and find out.

[f4m0u5]

So a leak that starts at 5psi of pressure is a loose enough coupler to let air in under light vacume? I didn't think that was a loose enough clamp / reducer to let it open up in those driving conditions

[Zba]

Can you be sure that it's not leaking prior to 5psi or is that only when it's audible? Are you certain that the hose will act the same under vacuum? You have a lean code and an inlet leak, I would start by sealing that up. It shouldn't be too difficult.

[axnjaksn]

agree try not to overthink the concern until you fix the obvious....a leak like that couple be much worse than just that....especially if your driving and bouncing around on the road, whats to say that leak isn't worse?? you did say it moves and the noise changes correct??

[f4m0u5]

No can't be sure it's not leaking under 5psi or that it acts the same under vacume that's your I was asking you gurus lol

It is a little hard to get to those clamps with motor in car. I just tightened one up on break. The second one is I need a lift and will hopefully tacked it after work

[Zba]

When you can try to put a turbo specific clamp on there
https://www.summitracing.com/parts/t...OEhRoCisjw_wcB

[f4m0u5]

Those look very nice,next time I'll have to.grab those type.

Put car on lift and tightened up the last clamp on drivers side. snugged up the passanger side while I was there. Also retighten all the boost hose clamps while I was under there.



What do you know still 12.5 a/f under boost...... didn't have time to do another boost leak test yet to see if I fixed the leak or not. But a visual inspection showed the reducer was still fully seated on turbo.

Tried new maf sensor. No change.

Fuel pressure is few over. It's at 55 at idle with vac line on. And around 61 with it off. When I squeeze the return line the pressure shoots up like it should.

Fpr is less then a year old. Running a 2 month old dw300 fuel pump/rewire. Fuel filter is only 6 months old


Idk what it could be. If it was a bad vac leak my idle trims would be out of whack too.