Fuel system - Pierburg

Useful links

Carburettor 2e3 refurb kit Part No ZE511 and £33.09 inc delivery or £13 from VW (if you can get it)

Diagrams/exploded views

Item	Description	Item	Description
1	Upper body	21	Tamperproof cap
2	Fuel inlet filter	22	Float chamber gasket
3	Float pin	23	Main body
4	Float	24	Part load enrichment valve
5	Needle valve	25	Secondary throttle diaphragm
6	Idle jet (primary)	26	Secondary throttle diaphragm pipe
7	Accelerator pump valve	27	Choke housing
8	Idle cut-off solenoid	28	Bi-metal choke assembly
9	Idle speed control screw	29	Choke flap
10	Mixture screw	30	Choke pull-down diaphragm
11	Accelerator pump diaphragm	31	Choke pull-down diaphragm pipe
13	Float chamber gasket	32	Roll pin
15	Vapour canister	33	Star clip
16	Fuel hose feed from pump	35	Fast idle adjustment screw
18	Main jet (primary)	36	Earth strap
19	Main jet (secondary)	37	Throttle body heater

Table borrowed from Gower and Lee [1] who can supply most of the parts

Note: If you require the 'choke flap repair unit' (van choke not working, no power at all until it warms up) then the Pierburg part number you need is 4-07301-13 (or possible 4-07301-10 might do). Gower and Lee don't have this in stock but they did have (May 09) 4.07301.09 2EE kits, the spindle is incorrect but I'm sure the plastic cam would fit. Image from Gower & Lee of this part number.

Jetting carbs

Aircooled.net (Carbs 102: Basic Jetting Theory and Procedure)

toomanytoys: Using a 1.9DG pierbug on a 2.1 DJ engine

If the truth be known.. it possibly would benefit from running some smaller jets. as the engine should give a bigger vacuum.. in reality the standard jets in a 2E3 work very well and give the same or better than DG mpg (I used to get same mpg but travelling faster) as the cam timing is longer so allows for the charge to get into the engine.

One thing with the DJ is you will have to consider what timing and fuel to use.. UL95 use 5 deg BTDC, or with UL98 you could go a bit higher maybe 8 deg BTDC but I would be a little wary of runnng 10 deg on UL98.. the Fuel Injection has better control over fueling than a carb.. unless anyone has put a lot of miles on a "DJ'd" DG.. I have, but on LPG which is a different kettle of fish..

Air filter.. if an early square type then dont worry, same as in Audi 5 cyl turbo's so flow plenty of air.. but I would make sure you rebiuld the carb before using it and set it up properly. If you can stretch to a rolling road session with someone that knows carbs, then you could fine tune the timing and carb settings/jets, but it will cost you.. but you would know whats going on..

Its a great conversion, lots of usefull torque, without compromising the mpg.. Oh and think about using the oil cooler from the DJ as the extra heat needs to go somewhere, plumb it in to the coolant return from the carb heating.. make sure the cooling system is in good nick and fit a new genuine thermostat (been some problems with some aftermarket ones.)

Footnote:

Don't Forget - There Are TWO filters

- (CovKid)

I'm posting this, peppered with relevant keywords in the hope that should anyone experience the same problem, they may just find a solution here.

Some months ago I ran entirely out of petrol at a busy junction in the pouring rain with my five year old son onboard. Fortunately a sympathetic bay owner going the other way saw the situation I was in and towed me off. I returned to the car park I'd left it in the next morning and it started with little problem with a gallon of petrol poured in, plus a dash down the inlet bore for good measure.

However, I had noticed a definate drop-off in power, mild hesitation on acceleration and what appeared to be a speed governer at around 65mph (mine will normally do 80mph fairly effortlessly). Last week I replaced the main fuel filter near the tank but this made little difference, neither did new plugs and a non rev-limiting rotor arm.

Its worth pointing out that the Pierburg carb in fact has its OWN filter (part 2 in above diagram), almost unseen as its fitted right inside the brass fuel inlet pipe - cone shaped, and only removable with a screw around the same diameter.

Heres the inlet pipe (photo courtesy of member 'Edoh'):

Using a screw extractor or self tapping screw to grip the inside of the plastic filter (photo courtesy of member 'Edoh'):

Filter removed (photo courtesy of member 'Edoh'):

Today I removed this and discovered it was totally crudded up with limescale/rust and with a careful and repeated wash in detergent and rolled between finger and thumb, it was finally clean once again. Refitted, power restored, smooth acceleration and no top speed limit. So, worth remembering if you have the same carb, don't forget to clean out this filter as well as replacing the one near the tank. You need something like a self-tapping screw to grip it and pull it out. Easy job though.

If you tend to run low on fuel or run out altogether, you could well find your bus runs like a box of loose spanners because of this with it dying at junctions, holding back at speed etc. For reference, the float bowl was free of any muck.

Pierburg overhaul kit and adjustments

Two excellent videos produced by Jamesakers on using a rebuild kit and checking carburetttor adjustments.

https://www.youtube.com/watch?v=VKD6ci8o06w

https://www.youtube.com/watch?v=U8qZwRgHX4A

Electrical plugs/connectors

We recently found fairly good substitutes for the original male/female spade connectors. They can be purchased from:

https://www.altecautomotive.co.uk/1-way-connector-including-terminals-1898-p.asp

Carb Wear - Throttle Flap leaks

If you have wear in a throttle flap, it will allow air in, causing poor idling and commonly, vehicle dying when you pull up to a junction. Air leaks anywhere on inlet side will cause this, but if you need throttle flap rebushing, Roger Ball in Clacton specialises in doing these. Please note however, cleaning airways/jets and fitting new gaskets is your job.

Roger makes a lot of stuff for custom bikes, mods for mobility scooters and so forth and is extremely well known for his engineering skills, so anything in the milling/turning line is his bag really.

Roger says carb makers tend to fit nylon bushes to throttle flaps from new but these eventually wear out. He dumps these and fits phosphor bronze bushes which have superior wear characteristics and lube nicely. He said give him a call and he'll sort your carb for you no problem! He does beetle, Type 2, T25, Webber carbs etc etc. "Most of these buses are well over 25 years old and its not uncommon for throttle flaps to get so worn they can have as much as an 8 thou gap, which is like a bucket to be honest. You'll never get it to run right when its worn like that" he says.

He needs carb body (where carb can be broken down into sections, you can just send body part that has the throttle flap if you like) as he needs to ensure it all fits together perfectly for you. Usually he'll put the throttle flap stem on the lathe to ensure it runs true first then measure everything to make sure the new bushes fit like a glove. I've seen Roger do many over the years (at least 18 years) and many 80/90 members will vouch for the quality of his work. Unfortunately I've also seen people fork out for brand new carbs when the old one only needed a clean, new gaskets and the throttle flap sorted. In fact the throttle spindle is about the only place that wear occurs and Roger's bushes far out-last the original ones. He'll tell you all about it if you ring him.

He does NOT clean & regasket carbs - thats your job.

Evenings (except weekends when he's out blowing his harp) are probably best time to catch him he says.

Rubber Boot on secondary throttle diaphragm