Re Kjet woes

[mikeki]

Hi guys

Can anyone shed any light on what is likely to be a familiar problem for storm or gti/gli owners. Here goes. I have a 1981 storm with engine code EG. Bought the car two years ago and have had problems getting it tuned. The car came with the original engine on 130,000 miles and one of the previous owners had the fuel system overhauled in 2001, with new filler neck, injectors and flushed out tank etc. The owner provided a reconditioned metering head, the rest was done by the VW garage based in Kent.

I had a lot of work to do on the car in terms of bodywork, suspension etc to get it through its MOT and left the running issues until afterwards. The first thing that was worked on was the fuel pump which failed a couple of times, and resulted in a quick fix by installing an inline filter between the tank and pump to stop any possible bits fouling up the sensitive pump. This worked and stopped the car cutting out unexpectedly. The running issues continued and these have been basically poor starting, in terms of the engine fires up ok but then the revs fall and the idle drops below 900 rpm and stalls unless the accelerator is pressed. The car would also idle roughly when warmed up, and then would not start properly if switched off and restarted again if left for any period longer than a minute or so.

As a result of these issues and problems with the cylinders, the engine was swapped for an identical unit, but from a car that had only done 46,000 miles, and the engine ran well before being taken out of the donor vehicle. After the installation of the new engine, the running issues continued and I referred the matter to my local VW dealer. Needless to say they were not able to solve the problem and if anything made it worse by not noticing that the filter had been leaking before they tried to set up the timing and mixture.

The latest attempt to sort out the problem has been carried out by a local garage and auto electrician, and so far they have been the only ones to make some progress. The accumulator was found to be badly corroded and did not appear to be maintaining pressure in the system. So that unit has been replaced together with the fuel feed from the pump, not cheap. I had thought that this may have cured the issues, but no, the car still starts badly, fails to idle at 900-950 rpm when warm, and refuses to re-start when hot.

My thoughts, apart from running down the M1 screaming, is could it be a duff metering head ? The cold start, warm up reg and thermo switches appear to be okay........any ideas or am I missing something that is very obvious?

Any help or ideas would be greatly appreciated to help maintain my sanity and get this good car back on the road so that I can blast around Derbyshire and Sheffield without breaking down!

Thanks

Mikeki

[monzajake]

Have you replaced the fuel pump relay ? could be braking down under load / getting very hot.
Also there is a small filter in the metering head next to where the main fuel line fits directly to the metering head.
If the car wont rev round to how it should ie its flat then the metering head flap is sticking.

[mikeki]

Hi Monza

Thanks for the input will look into those items and check they are ok.

Regards

Mikeki

[GTI]

Have you done the basic fuel pressure tests?

[mikeki]

Hi GTI

In the process of getting the tests done. The car is booked in and hopefully will get sorted before I retire!!!!

Thanks

Regards

Mike

[GTI]

Well, you need to borrow a K-Jetronic fuel pressure tester, check the pressures, (system & hot/cold control pressures) and test that your injectors are not leaking which it sounds like they may be. Do the checks yourself man!
I don't like the sound of your 'reconditioned metering head' it may have been messed with by someone. The other thing- you mentioned an in-line filter before the pump. That's a bad idea on K-Jet cos the pump is high pressure and flows a lot of fuel, there is already a filter 'basket' mesh in the tank, check that first to know the contents of your petrol tank. If that is your concern then Pierburg fuel pumps have a filter mesh in the inlet. You say you replaced the accumulator, what about the non-return valve at the exit of the fuel pump? That is responsible for holding pressure in the system also.

[GTI]

On reading your description again, you say the accumulator was badly corroded and did not appear to be maintaining pressure. Being under the car they always corrode externally, but was it actually checked and known to be faulty? Or was it just swapped by a garage cos they thought it looked a bit rusty?
The car cutting out unexpectedly will most likely be an electrical / fuel pump circuit fault. Or the pump itself.
Same goes for your cold start, warm up reg and thermo switches, you say they 'appear' to be OK but have you actually eliminated them as possible non-functioning components individually?
You need to do a bit of reading up to save yourself wasting money on randomly replacing components:

This will be helpful for you:
http://www.porsche924-944.nl/924/Troubleshooting.html
There is, of course, a goldmine of information about K-Jetronic at your fingertips on the web