84 gti K Jet

Changed the filler neck a few years ago , always keep my eye on it.Also main fuel pump checked ,system holding lots of pressure/ injectors cleaned ( not sure about them as they are over 30 years old ) all fuel lines checked// no air leaks in system/ new h.t leads,plugs,dizzy cap. rotor arm. have run injectors on home made rig , can,t really tell if o.k. Starts, no problem, have to keep tickling the throttle for a few minutes. ticks over @ 900 rpm no problem give it some revs and it misses and runs lumpy. have checked timing ( best i can because to get timing light onto flywheel markings , the  length of tubing to the air flow meter has to be removed, and will not run while doing this )  running on shell super unleaded 99 ron / been in my garage for 16 years (sacrilege i know ) i run it every 2 weeks. all new fuel. its on axle stands at the moment. ran it yesterday @6000 rpms at 70 mph at the wheels . still missing.what i need is a  K Jet whiz kid around the Heathrow area . Just do not know what else to do . Any suggestions

I think you should check your frequency valve. It adds extra fuel for cold starts and engine load. Located on the side of the airbox/air meter, and goes to your 5th injector on the intake manifold.

I'm not too good with these old Dubs, but, mine used to have that issues (88 cab). when the car is under cold start condition, the valve should "buzz". if not, that's probably your issue. When mine was not working, I couldn't touch throttle for about 2 minutes, otherwise it stalled. These are also known to give idle problems.

Worth a check. Good luck bud

I would check the cam belt timing marks, engine timing then look at the mixture, you really need the right equipment to test the mixture.
If you make a mark on the dissy you can always move it back to where it is now if adjusting the timing.

Sorry can't be any help with recommended any one in the London area, try calling some mobile tuning companies as I guess the cars not taxed and MOTed?

Thanks everyone for replying I will try with your suggestions . Your right it has no tax or mot

Do you have a fuel lift pump inside the fuel tank which feeds the main fuel pump underneath the car.
What size is your fuel tank, you can tell the size by the size of your spare wheel?

Thanks mark 1 gls I do not have a lift pump in the tank,and would the cold start valve affect the running once the engine was hot.

is it a tintop or cabby? have you changed the fuel filter?

if its a tintop they also have a filter in the tank that can get gummed up, is your fuel pump quiet when running or noisy?.

you need to make sure the timing is set correctly, try moving the expansion bottle and trying the light from there,

also you could try and clean the metering head with brake cleaner from underneath as they can get a bit sticky

also try stripping down and cleaning the warm up regulator as these can give problems.

Thanks sporttrucker for the info. its a cabby I will try the timing that way, does the warm up reg.strip down I thought it was a sealed unit.

so you will have a lift pump in the tank then, there is also a filter on that.

wur is easy to strip down once its off the car

Thanks sporttrucker will check on the lift pump ( is it easy to get out) and strip down the wur. will let you know how it goes

The WUR can be stripped & it is a sealed unit. The WUR is a major player in the start up of a CIS k-jet, it tells the fuel system to add more fuel on cold start, none on hot start & controls/helps the flow on running. If is this is not working right you will have issues on start up from cold, running & hot start… pretty much controls the pressure via a bi-metallic strip inside which moves depending on engine/coolant temperature, it has two gauzes on the inlet/outlet (13mm & 14mm bolts i think) through the Fuel Distributor, on cold start it adds more pressure & air through meter box plunger & plate along with the injectors… if you get good voltage from the test means you got good current but doesn't necessarily mean it's working correctly - an easy mistake which happened to me.

The WUR gauzes may have debris in them, you can strip this, the inside should be spotless, recommend spraying them with injection cleaner spray only & do not prod or poke them with anything at all as they're brittle. You can get repair/renewal kits for these for about £40 or cheaper, includes the rubbers, washers & plate.

When the car is warm it basically tells the 5th injector via the Thermo Time Switch, on the Coolant outlet on the head, not to work or release more fuel - the TTS also has a bi-metallic strip that opens the current/electric contact dependant on engine temp.
The 5th injector is relatively easy to check, disconnect the 2 bolts, 10mm i think, put in a jar & turn the engine over/start from cold it should spray evenly between 7-10 seconds, if it does then it's fine. this may be your 1st port of call. May want to renew the gasket if you haven't in a while.

hope this helps a bit… 

Thanks deandubya Istripped down an old wur and could not see any filters could you enlighten me as to where they are.I will check the 5th injector first to see if its working ok

no worries… on the WUR there's an inlet & outlet where the banjo's (13 & 14mm hex heads) were bolted into, on the top if you like, the gauzes/filters are in there… 

Thanks again I will take apart the one on car, I have also ordered new injectors as these are over 30 yrs old.I will let you know the outcome.

New injectors should help, I'm on my 3rd set after 290,000 miles in 30 years.  

Thanks mark1gls .I hope so will let you know how it goes

Fit a new fuel filter when fitting new injectors.

I changed my injectors when my car would run lumpy and rich when 1st starting then run smoothish but a little lumpy under heavy load once the engine was hot, it would start fine when hot, I did disconnect the electrical connector to my 5th injector which helped as extra fuel was not sprayed into the engine as my injectors leaked fuel when the engine was stopped.

There is 2 types of injectors so check you get the right type, you can mod the injectors to fit the right type of head.

Thanks good thinking I would have forgotten to do this

good call on the injectors… Perhaps have a look at your meter head gasket too, (6 bolts i think) these can crack over time as well.. only about a tenner but worth getting. While it's off, take a look at the meter plate/box area check for carbon build up - be careful!!  Use a non residual cleaner for this.. if you need to wipe, use 100% cotton… also think about getting a fuel cleaner which is added every other tank fill (being anal) it's about 50ml a time & it helps keep deposits off your lines/injectors etc… 

Thanks deandubya for your comments. Injectors arrived today  I have in the car at the moment bosch 049133551a parts in motion have sent me 0437502023 .I have been in touch with the seller and they say the first part number is obsolete and they sent me the second .they say this is the replacement. They look the same but without the hat on the end.Do you think these will fit