Boost issues. no boost and jerking mbc

[compton jay]

Sooo I got a mbc off egay and found a very old shittie boost gauge in the shed. Fitted everything and on the 1st click I feel boost but the gauge reads 0psi so I went 2 clicks on the mbc and I'm then at 4psi on the gauge but I feel that the car/boost feels a lot more than 4psi. I tried going 3 clicks and on boost the car just bucks like a fuel cut and boost gauge don't really go past 4/5psi when this happened

I have had this jerking before when the gauge read 10psi but that was only once

I removed the mbc and on actuator pressure the gauge is reading 0psi again even tho I feel I actually have boost and its fluttering fine!

What's the deal? Dodgy gauge or pants mbc?

I was going to bite the bullet and shell out for a gizzmo v3 ebc but worry it won't cure it

[compton jay]

Btw gauge is t'd to the fpr on inlet manifold

[jon200]

I would say a bad gauge, the mbc wouldn't affect fuel cut only air flow. Where is it plumbed into?


Sent from my iPhone using Tapatalk

[autosri]

Sounds like a knackered gauge either the diaphragm has a split in it or your pipe work isn't sealed and is leaking

Oh and the fuel regulator is a bad place to T into as a leak in the boost gauge/pipe work will act like a bleed valve for the regulator and your fuel pressure could drop

T into the dump valve pipe

[compton jay]

There are 4 nipples under the inlet what one shall I use? I think it's a crap gauge but can I really be over boosting on the mbc as like I said I'm hardly opening the valve.
I did a drift day at pod and on one click I couldn't keep the wheels spinning and on 2 clicks at 4psi(?) it was better but still lacked some go go. Wonder if to sack both off

[autosri]

You need a decent gauge before you do anything and use the pipe that went to the stock dump valve

[compton jay]

What pipes that? As it's all been blocked off. Yes the gauge must be buggered as I removed the mbc and it feels a lot slower now but the gauge reads 0 on boost. Boost gauge is 50 quid but wonder if to go to 200 and get the gizzmo as it has a real time gauge and I know it works 🤔

[jon200]

It will be the one sucking in at idle if you remove the bung in it


Sent from my iPhone using Tapatalk

[auz200sx]

What pipes that? As it's all been blocked off. Yes the gauge must be buggered as I removed the mbc and it feels a lot slower now but the gauge reads 0 on boost. Boost gauge is 50 quid but wonder if to go to 200 and get the gizzmo as it has a real time gauge and I know it works 🤔

Do this first

http://www.jull.net/s14-s15-tech-guides/boost-gauge

I suspect that you have both a dodgy gauge and a bad reference point and or leak. My personal opinion having tried both Ebc and MBC is that MBC are by far the easiest and most stable to set up and maintain boost and I thought my AVCR was the ducks nuts. Yeah Na

[compton jay]

Hope I'll have this sorted. I have ordered a 60mm boost gauge and picked up a gizzmo ebc-r very cheap so when it gets here I can see what's going on as the gauge must defo be buggered

Will update once it's all on

[compton jay]

Not got the boost gauge delivered yet but I got the gizzmo in and working.

Seems to be jerking on high boost still duty was 65 and gain at 25.

Turned it down to 60 and gain to 15 and I also pulled the elephant truck down a lil because I'm wondering if that's closing on boost

Seems ok on this setting gizzmo reads 13 to 14psi with the odd spike to 15psi

[compton jay]

Just to bump this. I've been wondering if the elephant trunks collapsing but also could it be it's. it getting enough fuel on higher boost?

When I had the car checked over I asked them to look if it had a 255 walbro pump and he said no it looks like it's possibly as gtr fuel pump?

I've got a 255 walbro spare so should I swap it over?