VW Golf Mk2 Owners Club

16v - K-Jetronic or EFI?

July 17, 2020, 03:45:08 PM

I've been seeing a lot of 16v bonnet photos which look like they have  converted their K-Jetronic to electronic fuel injection, sometimes doing away with the distributor as well.  Is this done for extra Horse Power, or am I missing something / making a mistake in restoring my engine and the original K-Jet for road use?

Re: 16v - K-Jetronic or EFI?

Reply #1 – July 17, 2020, 04:10:01 PM

It's possible what you are seeing are not converted Mk2 KR engines, but rather non-genuine 16v's with an engine swap to the 2.0 16v ABF engine from a Mk3 16v GTI. The look is very similar, especially the design of the intake but these run EFi so don't have the same injector set up.

An early 8v up to 87 runs K-jet and the 16v does.

If someone is converting a later 87 and onwards 8v (or other non-GTI) it's far easier to use the ABF than fit a KR as they don't need any of the CIS parts and can avoid the rather expensive high pressure fuel pump and hard to find under-car set up.

Granted some people my well swap out the K-jet for EFi. K-jet is great when it's working but it's getting on a bit now and is expensive to recondition and there are less and less people around that know how to set it up.

K-jet is good for tuning and once you've confirmed everything is in good working order and set up right it should be fine.

If you're doing a restoration then I'd certainly consider sticking with the stock K-jet system if you can. As the years go on there are less and less 'original' spec cars out there. They will be the ones demanding the premium prices if thats a consideration for you.

If I'm right with the ABF assumption then the extra HP will down to the 2.0 block not just the fuel delivery system.
The Corrado 9a engine is a 2.0 16v running K-Jet.

Personally if I was looking to upgrade an early 8v or 16v then I'd go for a 9a engine and keep it on K-jet but if I was modifying a Digi 8v or non-GTi then I'd go for the ABF.

Re: 16v - K-Jetronic or EFI?

Reply #2 – July 17, 2020, 04:40:04 PM

Thank you. That makes sense about the pictures I've seen and settles my worried mind down again!

Mine's an 87 16v with its K-Jet, so I was and now am again inclined to  stick with it.

I know what you mean about prices, though.  Is £300 plus vat about standard for a reconditioned fuel distributor? Do they come cheaper or should I get a spare one from the scrappy, buy a seals kit and have a go?!

Re: 16v - K-Jetronic or EFI?

Reply #3 – July 17, 2020, 05:02:57 PM

Yes, I believe I paid about £300 plus VAT from KMI for mine, although I had the WUR done too on my 8v so including new injectors, fuel pumps, including set up and rolling road my bill was closer to £2k so I'm not 100% sure what the individual part break down was.

One thing that was explained to me though, the internal parts are very precise. If a part has sat on a shelf in a garage/shed or taken off a car that hasn't been running or is part dismantled then chances are just the moisture in the air will have been enough to start the oxidisation of the tiny internal jets and fuel ways. So 2nd is next to pointless unless you buying as a spare.

I had a bunch of spares of all the parts and sent them to KMI to use the best bits, they basically told me it was all pretty much fudged.

Some people seem to have been OK with DIY seal kits, but to know you've got a sound starting point it's worth knowing it's been done right and properly bench tested with the correct equipment etc. You'll also need a fuel pressure testing kit to fine tune once fitted.

Re: 16v - K-Jetronic or EFI?

Reply #4 – July 17, 2020, 05:15:02 PM

Thank you. Yet again makes perfect sense. 

£2k. Crikey.  If Im not feeling flush enough to send the distributor  off before I refit, then I might try the 4-jar trick first to see //adjust the flow balance with new injectors, then maybe send it off to them if it doesn't seem to run correctly. Ive plenty to do for the 8 weeks they say is their lead time right now!

Thanks for your advice, as ever.

Re: 16v - K-Jetronic or EFI?

Reply #5 – July 17, 2020, 10:49:40 PM

May I please add another related question to this?

I took out my 30 year old injectors (with a great deal of difficulty when I stripped down and they were very shabby and dirty. I gently cleaned them off with a wire brush on a wheel, thinking they were probably scrap anyway.

picture attached before/after rotary brushing   https://photos.app.goo.gl/YJYPKSxxMDa2KNke6

They actually look great now, but will it last or have I damaged them in any way doing so, do you think? Are (were) they (e.g. nickel) plated or can they take this sort of cleaning? Judging by the rust on them, I suspect the hose end pipes were nickel plated steel and wont last long wire- brushed,  but interested in views on the injectors themselves.  I don't mind replacing them, in fact I was expecting to, but if I haven't damaged them I might see how they spray and seal  first?

Re: 16v - K-Jetronic or EFI?

Reply #6 – July 19, 2020, 01:31:59 PM

You need to run them into a bottle or jar and look at the spray pattern. Plenty of videos on YouTube. If the spray a good even most then they’re good to keep. If they squirt or shoot off to one side etc then bin them. Replacements should be around £30-50 each. Double check the part numbers. There are lots that look the same visually, but will have different spec.

Re: 16v - K-Jetronic or EFI?

Reply #7 – July 19, 2020, 01:33:10 PM

And if you do refit them use new o-rings.

Re: 16v - K-Jetronic or EFI?

Reply #8 – July 19, 2020, 04:49:47 PM

Thank you both. I will certainly check them for spray pattern and seal before I replace them, and also check the balance of the fuel distributor.  The two middle cylinders were looking a bit white when I split the engine so this may have been  fuel distribution or air leaks.
In my question, I was just also wondering whether I may have destroyed any surface coating they have by brushing them. But I suppose I can easily find out for myself with little risk if I pull them out and have a look once a year when servicing!
I see that I can currently buy Bosch Injectors at about £35 and VW ones at about £50. Looks like the kind of thing it mIght be worth having a new/spare set of in any case.