problem with car will not rev cleanly any ideas how with vid

my car was running fine today then started to splutter then cut out , checked  a few things so here we go this is what ive did
when put a live on to the 5 injector the car will start and run but when i take it off it dies. then i lifted the metering flap up no petrol came out into the injectors but if i gave the metering head a hit with a hamer it would spray a bit / is there a way of takeing my metering head apart to see if it has any gunk in it as i have just replaced the tank+filler neck due to going through 2 fuel pumps from old tank so think some gunk has got into the metering head and blocking the fuel feed ?????????? help ops:  

Wot metering head do you have on the car and did it run fine, before you started the engine conversion? Or if the metering head came off another car, did that car run fine before?

car was running fine


then i drove it round the corner then since then its as if its not getting fuel if i turn it over and put a live wire to the 5 injector it will run but as i take it off it will run for 4to10 seconds then cut out , if i leave it coupe of minites and lift the flap it sprays for 3 seconds then stops .  if i have my fuel pump running when i lift the metering head flap it dosnt spray fuel .

Worth a check with a fuel pressure gauge?

ive got another metering head so going to change it today and see if it fixs it :dontknow:

changed the metering head and now it sounds like its running on 3 but when you take a lead off it sounds the same ??? it runs better when cold then she will take a rev but when it heats up it wont take a rev and cut out if i rev it but will tick over if i just turn the key without throttle ??? help its doing ma head it     , what about the wur could that be the problem ?? low fuel pres??

right she starts half a turn of the key but sounds like running on three until i spray carb cleaner into the metering head then she runs fine?? do you think it could be a blocked injector??

anyone ?help

Have you tried a bigger hammer?

Seriously I would pull the injectors outs, and check the flow rates first. Measure flow into cups or something with the paddle at different heights. The Bentley manual gives some flows to check I think but you probably just want to make sure they are all the same.

If the flows are different its most probably crud in either the metering head or injectors. You can take the metering unit apart and clean, there is individual adjustment via the screw on top for each injector, make sure you mark this or dont move it unless you are prepared to setup the individual injector flows. The top bit of the metering head splits in 2 halves, do this and clean if you have access to a clean tank. wouldnt try this at home on the driveway!


Check the banjo bolt for fuel feed into the metering head, this should be a special bolt and have a fine mesh filter in it. I think there is also one on the pump outlet but not sure. This filter should stop most stuff getting into the metering unit. If either are blocked they will cause fuel starvation and intermittent running.

To check the WUR you need to get a pressure gauge, but this cant cause a difference in flows between cylinders.

Hope this helps and good luck. I spent ages getting k-jet working nicely on my mk1

Another thing to watch out for is a cracked plastic sleeve that the injectors sit in, I had a broken one and it was making one cylinder run lean.

was at her today and after getting her running {rough} took the plugs out and they where sooted up so must be over fueling? i think i"LL have to take it to a garage  

got another metering head put it on and she runs the same sht  , so it must be injectors ops:  going to check them tomorrow

i got 4 new injectors and put them in she ran ok for about 5 min then started playing up so i mucked about a notcied when i clamp the return fuel line she ran a bit better so it must be the fuel pump giving in .
can you run a mk1 gti fuel pump without the acumulator to run a mk1 1.8 16v kr

going to get brand new mk1 gti fuel pump on monday so fingers crossed it fixes her

Yes you can run the car just with the fuel pump connected but the accumulator is there to keep the system pressure up and stop fuel starvation.
Instead of running about changing things for the sake of it try working through in a systematic manner - as previously mentioned a)check the injectors, b)check fuel pressure, c)check fuel filter(s). After you've done these initial steps then you can start splitting the metering head etc. Parts changes are really a last resort otherwise you'll end up with empty pockets…fast

Cero said

Yes you can run the car just with the fuel pump connected but the accumulator is there to keep the system pressure up and stop fuel starvation.
Instead of running about changing things for the sake of it try working through in a systematic manner - as previously mentioned a)check the injectors, b)check fuel pressure, c)check fuel filter(s). After you've done these initial steps then you can start splitting the metering head etc. Parts changes are really a last resort otherwise you'll end up with empty pockets…fast

m8 am just trying to get ma car back on the road if you have read the pages you would know that i dont want to just spunck money on nothing i just want to have my car running yes :dontknow:  im just telling pepole that im problem solfing  :dontknow:

well i have changed the metering head that was the third one , fuel pump,four injectors are brand new, and she runs the same will start half a turn of the key but wont take throttle anyone got any ideas ??????    ops:

paul_c said

Worth a check with a fuel pressure gauge?

Worth a check with a fuel pressure gauge.

put the new fuel pump on and its still the same but if i clamp the return line it will take throttle so im thinking its the metering head any one ant ideas??

have you put an accumulator on yet, if not, do so!

tamthebam16v said

put the new fuel pump on and its still the same but if i clamp the return line it will take throttle so im thinking its the metering head any one ant ideas??

There's 2 ways to solve your issues:

1. Swap parts ad-hoc until, by chance, you find the problem
2. Measure things such as fuel pressure, mixture, to guide you and diagnose faults

Hence, I've suggested measuring fuel pressure, since this is instrumental (excuse the pun) in the operation of the K-Jetronic fuel injection. I can't say for sure, if not having an accumulator will affect its running. I've heard stories of people not having one and their car run fine; and its purpose is to smoothe out pressure pulses and leave a pressure reserve to prevent fuel vapourisation (once the car is switched off). But, VW fitted one and so have I (well, left it on, not explicitly fitted).

The fuel pressure gauge will INSTANTLY show up if its pulsing pressure or steady, which would show straight away if you need the accumulator or not. I guess it depends on the pump and other factors like the length of the fuel lines, the fuel filter doing a vaguely similar job, etc.

Also a fuel pressure gauge will actually, 100%, no guesswork, measure the system pressure and the control pressure you have, which will indicate if the injectors are opening and delivering fuel or not.