2.0 type 4 rolling road jetting

The guide I learned most from is here. Not very slick but if you start at the beginning then stop and take notes you'll learn a lot. I suspect swapping jets isn't going to be the answer until you've done the basics.

 

Hi Zed!
Cheers, I'm just learning... The hard way
I set the stops on the carbs to just touching +90 degrees. Shine torch behind...
The base mixture screws to 3 turns (some say do 2.5).maybe I should.
The only adjustment I did the other day successfully was the small slotted top mixture screw. (I didn't touch the large rpm nut) . Now this is not doing anything either 10 turns out (falls out soon after that) or 1 turn...
Before I could feel the improvement in adjustment like back to normal (not backfiring /whiplash). This problem is only under load, say below 3000rpm.
The main idle nut is 3 turns out which I set after cleaning them again, idle is solid about 950 rpm so not needed to change.
What should I change pls?

 

Cheers Andyv. I saw that a while ago, and it's good seeing him back with new videos... He shows what happened if it works OK. In the latest one he doesn't explain ' how' really.

 

Why would it work OK one day, park it (no changes) and then next day go back to how awful it was before 2 hrs and 20 miles of test+adj.
Makes no sense to me.

 

Something is "off" between 1000 and 3000rpm. Wether it is in both carbs, or either one, or timing/electrical- I dunno, may not have any hair left to pull out.
Her indoors is going spare, not pleasant at best of times...

 

Those settings are just a rough start point - to get the engine started so that you can set them properly. They are not intended as a "tune".
You know how to set idle mixtures?
Whereabouts are you?

 

Warm engine increasingly being setup for apparently running well ... so you degraded the setup for cold idle.

Idle set mega rich you can suck all the excess idle fuel into a fast running engine and it will run,
But end up too rich for idling.

At idle all three idle adjustments are providing fuel, the centre idle keeps the idle speed up.
Off idle it tends to more the primary idle jets, then the main jets at highest RPM.

While you are adjusting it, the idle speed is meant to change, according to the steps in the setup, you use idle speed changes to determine whether a particular adjustment needs to go one way or the other.
And the idle speed only has to reach the correct value at the end of the setup.


I have helped a couple of people set up these carburettors and been assisted by others at that time, working off the instructions in the Bentley manual.

 

Cheers, if it stops raining I will warm it up. Not easy with it 3ft from neighbours front door.
Am near busvanwhateverfest.
- If anyone can find me somewhere for me to buy to work on this stuff, I'd get them more than a crate of beer. Seriously.
If I can't - I'd better get rid of everything, no decent garages ere to fix these nowadays ....

 

These carbs are "emissions" carbs. Air is used to clean up what comes out of the tailpipe by leaning it out. Like EGR.
It's just over complication and extra parts that doesn't make it more efficient or powerful. Just a pain in the arse to get working with more to go wrong with it.
With Everything vw made after the 1500cc 1967 engine, Emmisions is priority then performance /reliability. Couldnt sell cars in USA etc if it won't comply legally.

 

I've used this as my main vehicle for 13 years. Be a shame to sell it on for a pittance. Hard work keepin it working that long....

 

OK so I went back to adjustment like you said.
I went 2.5 turns out on carb bases 3 turns on main co/mixture at top.
The carb base screw did not make any engine rpm change in or out.
More man-splaining pls or any explanin to just get this done/move on!!!

 

To eliminate other problems I ran it of a v. Clean can of fuel. I put it non electric replacements for the idle jets (kadron same sized). It had a clean new filter.
No difference. Same.
No smoothness 0>2500 rpm under load. (that's like 0 >30 mph). Will drive better once thro that, use up to full throttle . It will do 65mph in 3rd /more in 4th.
OK so it got through that can quickly/stopped. ...
Didn't really want to restart. Reconnect tank. Tip fuel in prime carbs.
Keep it revving... Get home.
Now seemed like 15% better. Obviously engine now warm.

 

Ps the rev limiter is now removed....

 

They are not speed screws, they are mixture screws. If you screw them in the engine should pop in the exhaust and falter.
Either you are supplying too much air/fuel via the top circuit OR your throttle stops are screwed in too far exposing the progression holes.
BUT
this is just for idling.

Are your chokes working properly? If they are stuck on you will be way too rich at lower revs until the air flow literally blows the choke flaps out of the way at higher revs.

 

With those carburettors, twiddling screws according to some 2 and a half turns mantra does not work well.


You follow one of the documented sequences as that isolates the effect of one adjustment before moving on to the next adjustment step.

In this way you end up with an idle setup that idles, chokes that work, a smooth transition from idle to main jets and smooth up to wide open throttle.

Getting annoyed and poking it doesnt work.

 

Gonna be difficult now isn't it...
Mike is correct, we've tried to steer you to setting these carbs up methodically but you're just stabbing at them randomly. IIRC you said they'd been fine for a decade then suddely weren't but instead of scratching you chin and trying to see what might have happened (loose fast idle link nuts is common) you've been randomly fiddling with settings and replacing jets until your carbs are now so out of whack you really do need to start from scratch.
Who knows, maybe there was never even a carb problem and your points have closed up or you have a cracked distributor cap?
As in all things you need to identify the problem as a first step.

 

It is difficult to describe exactly what is happening - to understand you need to be actually here, so that's OK.
I filled up with shell optimax petrol where I never use. I drove about 10 miles with some rough roads. At the end was a series of massive speed humps. Is died like it was out of fuel. Hard to restart, but eventually did idle. The way it ran that day is as it runs today.
It's quite violent to drive, not quite whiplash. Not a flatspot at all.
Whatever it is no definite evidence that I can point to.

 

The nearest experience I can relate to was decades ago. A customer bought a 1.8i scirocco in. Stupidly found an old can of petrol for lawn mowers, shoved it in. It ran terrible!
I went out in it, on test drive and the extreme jerkyness of it you could almost bang your fore head on the steering wheel. Obviously that fuel had to come out, and the usual method of removal from tanks there was a wet and dry hoover.
Ps No I'm not a great communication expert (or technical) !!!

 

A friend has recommended someone they used to fix their van.
Thanks everyone for your input.