carb losing vacume
Turbo Mini Forums

hello
can anyone help just come back from rolling road and he said carb is loosing vacume a full Boost and he carnt stop it said regulated is knacksrd as well on tickover any thoughts
thanks

Don't really understand what is being said.

The only 'vacuum' at full boost is the lower pressure across the jet compared to the fuel pressure.

Maybe on boost the engine is leaning out and he can't richen it up?

As for the regulator, I've never heard of one failing to work at tickover and then be fine on boost? Always the other way round, considering how they work I don't see how it can fail in the manner described.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Checked the obvious pipework? Blocked, splits etc. Also check fuel pressure at idle. Around 4psi I think.

hello
sorry was not clear did not realy understand him my self, right he said when it is ticking over the fuel pressure is reading 10 psi and running to rich, he said he could not adjust it any lower than that and when it is high boost it is running realy lean so he has turned the boost off all together
this is the part I don't understand he said there should be a black box ( on the metro turbo he said it was fitted next to the carb on the bulkhead) that controles the venting on the float chamber as u discribed, I had got the fuel lines plumbed in as everone descibed, with the two being blanked off, I find now the man at the rolling road has taken the one off to the extenshion piece from manifold to carb and joined the one from the vent stub to the one that comes off the plenum/regulater he also said the carb should be sealed (whitch I know) and said it must b leaking
please can anyone help, one the verge of setting it on fire thought it was going for checkup and I'm 400 pound down and scared to drive it
if its easier to phone me please feel free 07904160139 thanks

sorry its me again
the rolling road man also said the megajolt was spiking every now and then all readings would go sky high 30000 revs and so on please help

Fuel regulator should come off the plenum. I'm sure the hose below the fuel supply to the carb is blocked off. The actuator pipe is the only part I'm unsure about. My setup is not the norm, so hopefully someone will help you there.
Edit: bin standard metro ECU and any black boxes. :)

Edited by Jason G on 17th May, 2008.

for the spiking megajolt, check the grounding of the edis unit and the megajolt, i THINK THEY NEED TO GROUND TO THE SAM POINT (ooops caps)

also check the crank sensor is wired corectly and it is using screened cable, check the gap between the sensor and wheel too,

Oh and check the pugs are resistor type ones too.

Have you been drinking again Joe?

In the 13's at last!.. Just

I think hes been on one of those Green King tours at bury st edmunds!

lol Jason.

He's the newest member of 'hic' racing.

'hic!'

Edited by theoneeyedlizard on 17th May, 2008.

In the 13's at last!.. Just

On alandavies215 pipe issues, where do most of you connect the actuator pipe? If its sharing the pipe to the regulator, won't some pressure be lost?

lol,

its just my fat fingers this time!

actuator pipe comes of compressor housing then t piece to your bleed off.

regulator comes of plenmum chamber.

you need to block off lean off pipe and top pipe from float chamber.

if he unblocks this then it will lean off as the float chamber will not be pressurerised

always looking for them bigger bunches of bannanas

than u hogster so if he conected to two together like he did will this cause it to go lean on boost

Still not sure how it's been connected. any photos?

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

sorry no
the best way I can explain it is
a pipe comes off the extension gasket ( in between inlet manifold and carb) and joins the vent to the float chamber, I originally had these blanked off witch on here is right

Yes, blank them both off. But the extension gasket outlet could also be used for the boost gauge, or dump valve, or MAP sensor.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

thanks wil have it sorted now going to order fuel pressure gauge tomorow and hopefully sort that as well
cheers all