1.9 DG Fast idle and choke.

[Elsaetka]

Hi,

I have a 1990 1.9 DG with a standard carb which is running really bad from stone cold, have to feather the throttle to get it to idle and the first few minutes of driving are really difficult, absolutely no pull, just chugging. We live on a hill and put it this way, it's too nerve racking to try going up, I drive down, which is handy as it's pulling better by the bottom, about a quarter of a mile away.

Once over the initial warm up period it is spot on, even if it's been standing for a couple of hours it is fine. Once warmed up it idles slightly fast at 1000 rpm, it does not increase idle speed during warm up unless I hold the throttle, what a pain that is!

Air filter is new, plugs are not old, it just passed MOT at a VW CV main dealer, straight through but they struggled to get the emissions below the limit, said it could be dirty fuel / limited use over winter and needs a blast, not anything to do with the cold starting. Regardless of this the cold running problem is there summer or winter, so i'm convinced it is the choke not coming on coupled with fast idle set up.

I appreciate there are a good few posts on here, but I lack a little specific detail. Could someone point me in the direction or provide full clear details of how to set up the choke and fast idle. I'm fairly good with the spanners but need a step by step guide as don't wish to mess this one up, particularly need info on the following.....

1. Choke / pull down unit test?
2. Fast idle system, do I need to take the top off the carb to get at it, how do I adjust and lubricate it?
3. Are there any gaskets needed if need the top off?
4. Any pipes required / recommended? and any diagrams / best place for any parts?

Many thanks in advance.

[ermie571]

there are lots of brilliant carb posts on here...and have you looked at the wiki?

search for pierburg and anything that comes up for Kevtherev are brill!

[Ralf85]

Has this problem just begun? Did it start after somebody was servicing in the engine compartment?
Could just be the auto choke not setting properly. When you press the throttle down does it set the choke cam up to highest notch?

[kevtherev]

Once over the initial warm up period it is spot on, even if it's been standing for a couple of hours it is fine. Once warmed up it idles slightly fast at 1000 rpm, it does not increase idle speed during warm up unless I hold the throttle, what a pain that is!

do you depress the accelerator before starting the engine?
Cold engine.
Remove the pancake duct.
depress the accelerator FULLY once
look into the square venturi
There should be a square flap covering the venturi, with a slight gap.
tell us what you see.

is the flap like this?

1. Choke / pull down unit test?

This test will not affect your problem, the test is to see whether the choke opens under acceleration during warm up

2. Fast idle system, do I need to take the top off the carb to get at it, how do I adjust and lubricate it?

Ideally you need to remove the carb to see it and lubricate it.

3. Are there any gaskets needed if need the top off?

gasket set only needed if you split the carb.

4. Any pipes required / recommended? and any diagrams / best place for any parts?

No pipes, Gower & Lee for carb spares

Many thanks in advance.[/quote]

[kevtherev]

If you remove the carb you will see this
This is the fast idle mechanism



and here you can see the stepped cam and springs, all this can be lubed (note the stepped cam is on the highest notch (2000 rpm) It gets there when you fully depress the accelerator. The springs return it to the second notch when the acc. is depressed again.)



the mechanism moves this lever, which in turn opens and closes the flap, make sure this is not broken (common)



Here I have split the carb so you can see the springs and their correct attaching points



This mechanism is ultimately controlled by the choke bi metal spring in the spring housing.



if this spring is broken or not connected to the choke spindle then none of this will work

[Elsaetka]

Many thanks for the replies, Kev I am much clearer on it now, really good of you to take the time to do that.

I will study the info and look to giving it a good going over and careful set-up as described. In answer to your question, no I have not looked at the carb on start up after following the correct starting procedure, I will definately do that, I wouldnt be at all suprised if the choke butterfly is not closing to the tolerance and there is certainly no fast idle.

Prior to your responce best I found was this: Prior to the responces I found this:

https://onemanspanner.wordpress.com/201 ... w-vanagon/" onclick="window.open(this.href);return false;

Incidently, as I am researching the subject I was going to look into alternative carbs. General feedback seems to be avoid Weber as although they are good carbs, they may not suit a T25 DG. I was going to research Dellorto, I wondered what the Dellorto carb type is that many seem to rave about, (Dellorto 40s to be pecise). Is the DHLA 40 H the specific type suitable? and what sort of manifold would I be looking for?

Thanks again

[ghost123uk]

Re alternative carbs for standard WBX engines :- The Peirburgh 2E3 is an excellent carb when set up correctly (and not suffering from worn spindles). They are complicated though, as Kev's very good pictures show. We have a similar, but even more complicated 2E3 on our Scirocco I have had to learn about them as I do all that sort of maintenance myself. So, it's likely best to get your head around it rather than consider expensive alternatives that almost certainly won't give as good a performance (imho of course ) If you follow Kev's advice methodically, you will get it sorted

[Elsaetka]

Your post spurred me into action rather than just talking about it, the engine is stone cold and following the correct starting procedure the choke flap is not moving, (see pic taken just after engine started, thanks to my wife while I held the throttle!). It's sitting firmly in the vertical/ open position, no wonder it's running badly, i'm suprised it starts at all.

The bi-mettalic spring in the choke mechanism is intact. Other than it being assembled incorrectly with the spring loop not located onto the actuator, I have no idea how that can happen.

Anyway, given I have found the main problem area, coupled with the guide, I should be on the way to sorting it out.

[kevtherev]

good news.
Keep us posted either way

[kevtherev]

I wondered what the Dellorto carb type is that many seem to rave about, (Dellorto 40s to be pecise). Is the DHLA 40 H the specific type suitable? and what sort of manifold would I be looking for?

Thanks again

DRLA 36's are more user friendly
They are the rolls royce of carbs, induce stupid grins and constantly taunt you into "heavy foot" due to the awesome power and induction roar they deliver.
However all these dumb ass grins come at a price, but your local Sheik will love you to fit them.

A 2e3 on a campervan seems more elegant.

[kevtherev]

This picture shows the range of adjustment with the three screws
Use this adjustment to set your fast idle.
Turning the housing clockwise will keep the choke on a few minutes longer and slow the fast idle mechanism down
Do not pre tension the spring, just fit the dog in the spring and set it in the middle of the adjustment.
Remember to adjust the choke flap gap (as per haynes) when you have a choke operation

the wire is attached to a heater, this speeds up the flap opening time.
The flap should be fully open within 6-8 mins

[Elsaetka]

I certainly will keep you posted on developments, however as I will probably get frost bite out there at the minute, I will have to adjust the carb ASAP, mind you I may be brave and sort it quickly.

Given your comments on fuel consumption I will kick the Dellorto idea into the long grass, I would far rather improve my MPG than make it worse! I am not too worried about high speed / high torque in a camper van. Mind you I must be getting old! My wife added flower decals to the high top, and it took me a while to come to terms with that, I almost needed therapy; but i'm in a different place now compared to my sports car days, how we all change.

Incidently the van just passed MOT, straight through at a main VW dealer, however they said they struggled to get the emissions down to a pass level. Probably as it sat idle all winter.

I will adjust the settings as described Kev, hopefully to make the choke activate, but if anyone is able to answer the Dellorto question, this will probably turn into a very handy thread for future reference.

Questions being:
1. Why are Dellorto 36's best / user friendly?
2. Why is a Dellorto 40H for example not?
3. Do Dellorto's need a specific manifold and if so what specific type and where from?

[kevtherev]

Flowers on the camper....

Get a grip man!

A few of my friends, have fitted delorto.
Ranging from 28's to 38's
The 28's gave a reasonable fuel economy with a light foot.
With a heavier foot they delivered.

The bigger the venturi (chokes) the more air/fuel gets sucked in.
So the 40's give more ll the time.
Setting up all four dells takes a rolling road session to jet up and synchronise properly, although you can get them in the ballpark second hand.

[Elsaetka]

Ha! flowers (i Know).

OK, based on the advice provided I gave it a go today, although given the very cold temperatures I didn't hang around too long, roll on the summer.

The choke flap was fixed in the vertical, I took of the auto-choke unit, the spring was attached to the actuator which wasnt a suprise I suppose as I have never touched it in the 8 years I have owned it.

I applied a small amount of pressure to the actualtor and with a 'click' the choke flap became free. I set up the fast idle as per Haynes as you said Kev. I also cleaned and lubricated the fast idle mechanism which was very dirty and without a doubt not moving freely.

I reassembled, making 100% sure the auto-choke bi-mettalic was located on the shaft lug, and the choke is now operating.

Obviously I will be more confident when it has seen some use in the coming days / weeks, but without a doubt a massive step forward thanks to Kev and the forum.

[kevtherev]

..and thank you for concluding the post.
It helps others when searching (desperately) for answers.

This is why we are all here.