On the advice of the man from FastRoadCars I tried putting in 115/120 main jets. This has helped A LOT, the car is now drivable but it still misfires slightly around 2,000 RPM (most obvious when cruising at 30mph in third gear). So a richer primary has helped it along.

For comparison

Land Rover 90 factory jetting for the 32/34 DMTL

1983 - 1986

Engine 2.25 Litre!

(but deliberately restricted air flow I think)

Primary / Secondary

Venturi 24 / 25

Idle jet 55 / 60

Main Jet 110 / 115

Air correction jet 160 / 160

Emulsion tube F30 / F30

Accel. pump jet 40

Float level (mm) 7

Needle valve (mm) 1.75

so its richening the mixture and covering something up, this engine is almost half the capacity.

There is a sucking/whistling noise now since I reinstalled the carb, coming from around the carburettor somewhere but I can't pinpoint where. It doesn't seem to respond to spraying stuff around the base, but there must be a problem or else it wouldnt make that noise. The adapter plate has some scratches on it, but I have put sealant around both sides of it just to make sure. The heater might well be the problem but the rubber block is looking a bit tired too, it has some damage on it on the top which I tried to fix with sealant.

richening the mixture is covering a air leak if you ask me

the hissing also points very much to a airleak

i know its frustrating me repeating myself , but i still think theres a issue on how its fitted

I have everything down nice and tight and sealed, the adapter plate does have some scratches on it too but nothing too bad. I hope the replacement block does the job because the old one is a bit tired...

I just drove it from Trowbrige to Bristol. When it was cold it was really bad and kept stalling, but once it warmed up it was fine. It has used less fuel getting here than with the old Pierburg. It went very well too, no problems getting up to speed. It does still make the noise though so it clearly aint right and the cold starting/running problem would seem to show that.

Oh well, at least I can use it now so the pressure is off.

vac pipes all good and on the right outlets?

The pipe to the air temperature sensor (what does that even do?) in the airbox and the pipe to the vacuum advance and the one from the accelerator pump are all solid, those are the only pipes I know of.

Rocking the aircover back and forward makes the noise change. Definitely a leak at the base somewhere.

To be on the safe are replacement base adaptors easy to find? DMTL and DMTR ones should be the same. FastRoadCars doesn't do them separately.

air temperature sensor (what does that even do?) in the airbox

vacuum from running engine pulls a flap so warmed air from near the very hot exhaust manifold enters below a certain temp

for better running while warming in cold weather... any water condensation is rapidly evaporated and sucked away through the engine

once warmed up the valve closes and a spring closes the flap so only cold outside air enters the inlet

i don't know whether it blends cold/warm air or just swaps quickly over to cold air

To be on the safe are replacement base adaptors easy to find?

Found mine on eBay, new old stock from closing down hazell-quinton

(?) stocking motor factor.

I had a similar problem recently.It was shot points and a worn bearing in the dizzy. I would advise taking you are dizzy off n replacing you are points n rotar arm n getting you are timing all done. Personally from experience working on mrk2 polos i dont think its anything to do with the carb/s Could be wrong but just my own opinion bud.

he wont have points...its a newer car

Yeah, it uses the later transistor ignition system, but the car has major problems starting and running from cold at the moment, spraying WD40 into the distributor cap fixes it, but I need to do it each morning. Getting a new distributor cap (and a set of leads and plugs just to do the full thing) next week.

The carb is definitely leaking air at the base, and I am still looking out for a new adaptor plate... really I don't think there's much else to do until I can fix that bit of the problem.

Thanks for your help guys!

i think they did several types of base adaptors....mine is a alloy plate that bolts to the orig rubber mount

whats yours like? gsf etc should have the orig style ones

I didn't know GSF did parts like that, it's to mount the DMTL/DMTR onto the original Pierburg rubber block.

It has four holes at each corner that the Weber carb mounts too, the one in the top right also fits the rubber mount and is done with a shouldered stud. There are also two hex bolts that go into the rubber block.

ah no , they will only do the pierburb bit...sorry for any confusion

how have you ruined the new part?

some pics would still be good..cant u get camera off a mate?

Edited 13 November, 200916 yr by steveo3002

This is what I have in terms of adaptor plate if this can shed any light? (sorry poor picture from a while back) as said before a new paper gasket and blue hylomar have made it trouble free.

One other thing was I had an on going problem with headgasket type symptoms which turned out to be corrosion on the inlet manifold (where it has the heater element hedgehog) it was a small hole that was allowing coolant in now replaced with GK manifold. Maybe check your inlet manifold on that underside. coolant can be very corrosive on alloy when in contact with air, My car had sat for a year and this problem was not obvious.

That set up is a fair bit different to mine. The adaptor is a metal block that the Weber sits on, and that bolts to a thick rubber block that sits on the intake manifold. The rubber block was used to mount the Pierburg to the intake before, my conversion kit told to reuse it.

Edited 13 November, 200916 yr by anessen

The damage to the block was purely negligence on my part. When I first installed it I overtightened one of the nuts and I couldn't get it to come off, so I remove the rest of them and tried rotating the carb to get it to loosen while turning it with a ring spanner. Afterwards I found a nasty gouge in the metal of the adaptor plate. I've tried using a silicone sealer on it, and I don't know for sure if that is what's causing the problem, but there is an air leak and the adaptor is damaged.

right well the original pierburg rubbers are well known to wear out ....push and pull on the carb when its running and see if theres any hissing /sucking sounds ..or any change in the way the running sounds

as for the gouge...get something like some 180 paper on a flat piece of glass and sand the adaptor on it to remove any high spots...if the gauge is deep smear in some chemical metal or jb weld and then sand again ...you can mist on some aerosol paint , then observe how it sands off to be sure its fairly flat , the gasket will take care of any minor problems

could also hold a steel ruler under the carb...make sure you haven't bent it over tightening things

and yeah it makes different sucking and whistling noises if you push the carb back and forward.

The adaptor is this thing (minus that thing on the left):

Edited 14 November, 200916 yr by anessen

sounds like the rubber basplate is buggered then

I bought and installed the adaptor plate I posted above, and gave the manifold, rubber block and adaptor a thin coat of Hylomar Blue before I put them on.

Since then the car seems to run very well when hot, but now it completely refuses to idle cold, I have to keep my foot on the accelerator to get it to go . I think the choke fast idle is almost 0 at the moment so I'll have a play with that, and I know the jets aren't right for a working set up because I've been buggering about with it getting it to work on a vacuum leak.

With that said, does anyone have a good jet set up for a DMTL?

Currently running:

Main: 115/120

Air Corrector: 155/185

Emulsion Tube: F22/F30

Idle: 45/70

Edited 4 December, 200916 yr by anessen

do you reset the idle each time you tinker with it?

Eh no, at the moment it's idling at about 1,200rpm without choke when it's hot. When it's cold it just dies choke or no.

well tweaking the idle screw would be a good idea ..

and set up that fast idle screw a bit so it boosts when cold

I bought and installed the adaptor plate I posted above, and gave the manifold, rubber block and adaptor a thin coat of Hylomar Blue before I put them on.

Like he said, sort the idle.

With that said, does anyone have a good jet set up for a DMTL?

Currently running:

Main: 115/120

Air Corrector: 155/185

Emulsion Tube: F22/F30

Idle: 45/70

That should be good. The F22 is wide for higher compression or strong vibrations. F30 is a good all rounder often needing

5% larger main. With no other mods Messrs Carburatori Weber are surely right.

Depends what issues and wishes you have. Possibile combinations are huge.

With some jet files infinite.

Swapping the F22/F30 emulsions for better second stage pickup has been tried.

Other possibilities are heading lean with two F30 tubes with much bigger air correctors. Your cooling system needs to be up to this.

Lean gives more power but it is dangerous. I've tried 105/F22/155/45 115/F30/185/70 once again in my 22/22.

It's still got the 50 pump so economy would suffer as Weber warns,

and although 1500rpm to 2500rpm feels quicker, I'm down to 42mpg.

At 1200rpm 5th gear very light throttle I get some faltering.

With twin F30s I typically get 47 in winter and it's smooth as silk.

X1/9 racers like F24 tubes and lowering the float level.

Alfa Romeo Giulietta Sprint 1300 (80BHP) used:

Main: 130/130

Air Corrector: 210/150

Emulsion Tube: F13/F13

Idle: 50

Pump: 60

F13 has low holes and is narrow to increase reserve for acceleration. Needs larger air to compensate.

Though this was the 36DCD and it's a twincam engine.

On the other hand 36DCD is progressive like the DMTL. It has 24/24 venturis.