Help!!! Carb
Turbo Mini Forums

New Carb makes the engine die under any load. An 850?s got more go at the moment.

Can any body help??
Apologies if this is a bit long

My Old carb was not a turbo carb. The bottom half was a normal 1.3 metro but the dash pot was turbo here's a pic.



It was connected as follows:
No. 1 Fuel feed from regulator
No. 2 Joined T-Piece which connected to Plenum take of and top connection of Fuel Regulator
No. 3 Breather Blocked.
No. 4 to Boost Gauge and vacuum advance
No. 5 to Dump Valve

This ran OK for a long time. After a new head and a few other bits and pieces being tidied up I put a Turbo SU reconditioning kit on it. After this I took it to the garage but it wouldn?t richen up (Co2 maxed out at 0.35). We lifted the needle in the dash pot to get to mixture up so I could drive it home. Car drove OK top end was a bit off but that was expected as the needle was pushed up. I put this down to one of the Turbo recon bit not quite matching the standard 1.3 SU.

So I got a Turbo carb and fitted an SU reconditioning kit to it (minus the spindle bits, always had problems in the past getting them back together with the bloody springs).

I?ve connected the carb up using the diagrams in the How-To section.
The car idles and revs ok but is almost un-drivable, engine feels very sluggish if gets close to the turbo it just backs off big time and gets the odd pop around the turbo or carb.
Car was warm but only drove about 200 yard, scared of doing some damage.
Here?s the new carb with connections labeled.



New Carb connected as follows:
No. 1 Plenum to fuel regulator No. 9 (T-Piece goes to inner bulk head where ECU is mounted but is blocked off)
No. 2 Fuel feed from regulator ? No. 8
No. 3 Goes to No.6 on manifold
No. 4 Blocked
No. 5 T-Piece to Boost Gauge and vacuum advance
No. 6 Goes to No. 3 On Carb
No. 7 Sandwich plate to Dump Valve

Anybody got any clues??

Edited by Soton1310Turbo on 1st Jun, 2004.

to me that looks connected fine.

Fuel pressure ok? Filters clean etc?

Is the plenum gasket the correct one, some cover up a hole that presurises the carb so could cause this problem.

Sure others will think of more, im knackered, i think of more tomorrow!

Think these pics should definately be in the faq they are very helpful.

I had to change my dashpot screw in thing, with the plastic thumb screw on the top. I had to do this because the threads were nolonger there. I used one from a standard 1.3 carb is this ok? It doesnt have a rib round the copper bottom bit, and also i didnt replace the metal thing arroudn the top plastic lid! Is it needed? I thought it was just a bodge from previous owner!

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

Can i ask once this guys problems are sorted:
The green circle,
This is the clip im on about that i dont have, and im using a 1.3 carb's screw in thing.


The red circle,
Where do these connections go to? Is one to the breather? Is it for the servo as i dont have one. I am hoping to use a T piece also, and have one to my boost guage and one to the breather (think this is where it went on the metro before, well it went to the bottom of the air box where the turbo's sucking pressure was.

the yellow circle,
Is this a custom take off, as i dont have one?

Can i use a T piece and have all of the breathers connected into one of the small k&n air filters as pictured above?

thankyou

james

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

I cant be off much help here as I am a twat !

but I have to say that looks F'CKiN beautiful !!


Good job !!

S

TurboLessTosser

LOL @ B12.......... hes right tho... mine will never look like that!!

Sooperdooperturbocooperexpertengineering!

Iain thanks for the reply

Fuel pressure - I?ve got a Gunson Lo-Gauge on order as of last night
Fuel Filters are clean, both replaced recently

Plenum Gasket- I?ve never noticed before but is there another hole which should be clear other then the obvious one? If yes then it could be that I?ll take it off tonight and have a closer look

Feebleuk
I?ve had a couple of previous owner bodges too. Luckily for me it was my brother so I?ve had words
Seal at the bottom of the dash pot isn?t essential provided it makes a good seal, tiny bit of hylomar helps mine had this for nearly 2 years and was fine

Green circle once again not 100% essential I ran without one for nearly 2 years no probs.
Be careful with std dash pot screws some I?ve seen have couple with small holes in the top + pressure from the turbo will push your oil out.

Red circle T-Piece goes to Anti Run On Valve, other pipe goes to break servo via a non return valve don?t think the Servo likes + Pressure from Turbo?s. Both breathers vent to atmosphere with two K&N breathers stubs

Yellow circle is a standard turbo carb take off. On a turbo the vacuum is taken off before the butterfly in the carb normally aspirated one it?s after also used it for my boost gauge.

Cheers to B12 and mini-marauder
Amazing what few bits of blue hoses do, brightens it right up.
All my standard hoses had got covered in oil at some point in their lives, I?ve had shed loads split recently so said Bolox and bought silicon. Pricey but it should last

thats great! thanks for the big reply! helped alot that

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

I've got it going a bit better now

After reading the carb stuff on www.turbo-mini.co.uk. I think the bloke who's site it is, is a member on here
Very good site load of interesting stuff and very well explained

All I've done is to block the pipe that links the carb to the manifold at both ends and have soldered up the popet valve on the carb butterfly.

Seems a bit better now at least it'll get onto boost now

I'll get the emissions set a my local garage and then book a Rolling road when I've got some money

sorry to be a pain in the ass

but why would you want to

""""All I've done is to block the pipe that links the carb to the manifold at both ends """

I dont understand what it is for !

S

TurboLessTosser

Quote from http://www.turbo-mini.com/9764.html

"the Rubber Balance pipe. This is actually a ?part-throttle? lean off device, and is also found on some ?economy models? of other SU fitments. This has an accurately sized orifice that is tuned to the standard engine. As soon as any modifications are made, this becomes incorrect, and can cause excessive Lean out under part throttle or gentle acceleration.
The best all round way to deal with this is to re ? calibrate this, by adding a very sensitive restrictor valve into the pipe and spending hours trying to re-calibrate it.
If you are only concerned with power and drivability, then the best action is to simply plug the two ends of the pipe.
"

makes my car run better for the moment

Got a couple of other plans for minor mods then might change it back during a RR session see what the operator says and how it runs

matey do you mean the pipe that runs from 3 to 6 ?

TurboLessTosser

Yep - that's the one!

http://www.manchester-minis.cwc.net/technical/turbo-carb.htm

Im bringing up this page again!

Can i basically get a normal good 1.3 carb, and connect it following the diagram above? Cant find anythign else in the FAQ ill keep looking though.

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

No. A turbo carb is different and you risk blow fuel out of things onto a hot turbo, not much fun!

Especially on a road car!