Cabby running funky

Gti cabby help needed!

Problem is up to 3.5 k the car judders, over 3.5k smooths out and pulls like a train.

When I say judders the revs stay stable etc it dosn't cut out etc?  

Any ideas?

More info needed.

Engine?
K-Jet?

Is it only when cold? warm?
How does it start?

1.8 1988 cabby

Hot or cold, same issue, when starting from cold it's a pig but when it's warm it fires straight up.

But still judders?

Just fitted dizzy cap and rotor arm, no change, can't do the timing as the dizzy has welded it's self to the block.

Exhast smells a bit of fuel, no smoke and occasional misfire?

Have you checked the CO2 count?

It could sound like it it running to rich?!

Turn the mixture a little anti clockwise to make it run leaner. It is very sensitive. 1/8 turn could be enough.
It is a 3mm Allen (hex) and be careful as it is a sensitive part of the engine.

Tak a look at the "Fuel Injection" link under "Technical" to the left of this post…

Hi Funk-star, i have the exact same symptoms Over the past 2 years i have replaced everything to do with the fuel injection system from Filler neck to Injectors with either new parts or parts i know work as they should but still have the same problem. I have had the WUR checked and is ok, as is the Thermotime Switch, Aux Air Valve and Cold Start Valve. Somebody has recently said to me it maybe timing related as i have replaced things like injectors and metering head and therefore the timing may need to be set up again. I do not know if this is true or not but its worth a try. The running does improve slightly when the car is hot and has been running for a while but there is still a major misfire there.

P.S Engine is 1.8 GTI, DX.

Also, have you checked for air leaks? Especially around the inlet manifold. There are 6 bolts which hold this on, might be worth checking to see if these are loose/missing. That could explain why it starts no problem when hot and revs out above 3500rpm.

found a decayed pipe and replaced it, seems to pull better but still has a very slight miss?

Going to set the co up and throw some injection cleaner in the tank, then run it!

Also fixed a broken wire to the 5th injector which might explain the crappy cold start?

i have the same problem aswell, changed loads of parts but still have the problem around 3500 revs. i also had the seized dizzy problem, the diagnostic auto tune bloke couldnt do it, i ended up spraying it with wd40 every couple of hours and then clamping on some mole grips and waggling with plenty of elbow grease.
which hose did you have to change?