Porsche Enthusiasts Club Forum

I had exactly the same thing happen a few years ago, the AA man had most of the Kjet off on the drive. Then I noticed that as soon as I released the key and the engine stoped there was no ignition light. Turned out to be the connecter block on the back of the ignition switch ! the man who can rigged up a couple of bits of wire and showed me how to hotwire my car untill I could get a new block

Worth checking.

I will investigate the ignition setup at the key, thanks,

it was not the best running engine in the past , I do not mind spending a few pounds doing a rebuild on the fuel metering head , it is 34 years old and can only benefit form a refresh.

cheers Roy

When I was chasing mine round in circles it was missing on just one cylinder. After I'd had all the plugs out and changed them, removed the injectors and tested them for flow *(this is relevant!) replaced the seals, cleaned the HT leads, distributor cap and arm, then changed all the leads round to try to identify which one was faulty - for the misfire to still be there on the same cylinder.. That was when the fuel distributor came into the frame. It comes apart easily enough, but before you do make sure you can get the right seals for the plunger. It's actually a very clever system and works very well, but when you see the size of the WUR hole in the diaphragm between the two halves of the distributor you can see why it is imperative to make sure that the diaphragm is oriented correctly before re-assembly - I used a smear of Hylomar that I'd thinned with cellulose thinners to be sure of a seal.

Even after this it was still missing on the same pot, but that was then I discovered these little filters that are about the size of a match head and sit under the banjo bolts that secure the high pressure fuel lines from the distributor to the injectors. I used a sharp wood screw to gently ease mine out for cleaning before reassembling. The motor started with the first turn of the key and hey presto - misfire disappeared...

Try this Rennlist thread and here is a very useful pictorial showing a 5 cyl Audi, but it's the same principle and shows where these tiny filters are ...

* it's relevant because despite everything that was not right the injector was still functioning and delivering fuel - a proper Red Herring!

Good luck!

thanks greggers,

that is some useful information there.

cheers roy

It might be worth looking at your Idle Control Valve too as these can sometimes get bunged up with all sorts of crud .. You're not supposed to be able to disassemble them, but you can if you're careful.. or perhaps fill it up with brake and clutch cleaner and give it a good shake.. test it in the freezer too... If yours is fooked then some Ford engines have one with roughly the same disc pattern, I think I got one from an Escort..

Cheers

Greg

latest update,

fuel metering head stripped cleaned and rebuilt with new parts,
new air filter fitted.

same symptoms remain.

car will not run, it will cat and reluctantly rev on the starter but dies as soon as the key is released.

anymore ideas to the possible issue !

cheers roy

You need to check there is power on the ignition coil when the ignition switch is in the run position. If the ballast resistor fails, you would have a 12v feed to the coil when cranking, but nothing when the key is released.

hi,
my car is a 1981 it does not have the ballast resistors,
the resistor wires on my car seem to be in good order, but would really need to check with a multimeter.

Have you checked for air leaks on the induction side of things?

David

Just reading through this and hopefully offer some useful help!

Currently you have fuel (if anything to much if the plugs are blacking but you might find the mixture is totally wrong after rebuilding the metering head), you have a spark and the air flap is moving ok?

Firstly I'd check for air leaks by removing the pipework from the metering head to the inlet manifold and check all joins. When I got mine someone had over tightened the jubilee clip on the hard plastic pipe in the middle and it had partially collapsed letting in loads of air & k-jet really doesnt like air leaks! Mine would only just run when cold until I found the leak. maybe get some insulation tape and wrap each joint to make sure its air tight?

Timing - any chance the timing belt has slipped? you can line up the marks easily enough by removing the cam cover and check the rotor arm is pointing correctly at TDC

Ignition switch as previsouly mentioned. If this is burnt out which isnt uncommon it could be cutting power when you release the key? that may explain things?

Fuel pump relay. Doubtful and I'd expect other symptoms including lack of fuel which it doesnt sound like you have.

Good luck

hi,

thanks for the info,

I did notice the same issue with the hard plastic pipe on the inlet side to inlet manifold.

just to be sure the ignition switch is located at the ignition barrel ?

cheers roy

Yes, thats the one. This should give you a fighting chance:

http://924er.blogspot.co.uk/2011/08/cha ... witch.html

Have you checked for power at the ignition coil?

that does not look like much fun

update ,
put a new ignition switch in, made no difference.