ABF on K-jet - setting up & troubleshooting? Fixed and MOT'd!!!

Hi All,

Me and a mate have recently installed an ABF engine into our Mk2 16v track car. It's up and running now and we have it idling pretty well and it seems to rev ok, uses all the original k-jet equipment which was working great on the KR engine that came out.

I tried a little test drive today and the car struggles under load and wants to cut out, has no 'go' at all and though it will accelerate relatively well in 1st gear, it sounds as if it's knocking from the top end, pinking perhaps - like a tappety noise? In 2nd gear it won't pull at all from low revs and shudders unless you dip the clutch and rev it quite hard.

So, what I need is basically some info on setting it up from scratch at home as I think I've messed so much with the mixture, idle speed, timing etc etc that I need to just go from the basics and work along one thing at a time.

The problem being that I can't get it running well enough to take to the local MOT place to put it on a gas analyser to set the mixture yet - so, what is a good starting point for the mixture setting? I need to get it running ok at home, then I can take it to the MOT man to set the mixture correctly.

So far I've:

1. Checked air flow plunger flap is set correctly
2. Set cam to crank, intercam and ignition timing correctly (6 deg BTDC)
3. Set idle to around 1k rpm with ISV and crank case breather disconnected
4. Fiddled with the mixture screw (3mm allen) to get it idling as it wouldn't before!
5. Checked all wiring, senders etc ok
6. Checked, cleaned, secured vacuum hoses etc

So - where to start? Any tips much appreciated - or if anyone in the Cheshire area has a gas analyser they want to lend that'd be great too!

Here's a few pics to make this post a bit more interesting...






Cheers
Stu

 

Just to add, I was checking various things on the car today and popped the plug leads off one by one. Removing either lead number 1 or 2 would cause the engine to cut out, fair enough. Removing 3 or 4 would cause the engine note to change slightly but it didn't seem to run much rougher, could this point to an ignition fault on 3 and 4 as they didn't have much effect on the running when removed?

Also, whipped the plugs out and they were all a little sooty (mixture too rich?) but not bad really, certainly nothing to worry about.

I think I have richened the mixture about 1 - 2 turns from how it was original with the KR engine, using the 3mm allen screw in the metering head to make it idle as it wouldn't with the previous settings.

Any ideas?

 

I know this may sound foolish.........but are you sure you have the HT leads on the right way.
When i converted my mk2 to ABF,mine was doing the same thing.....turned out to be me

 

Seems to be an ignition fault somewhere along the lines.

I'd double check the timing to begin with and confirm you have it set up at 6deg and not 0deg. It's quite easy to make the mistake.



Use the groove not the dot.

Sorry if I sound patronising

 

Had same problem. Now running on an aftermarket EFI system. Much better and very tuneable.

 

Thanks for the replies, much appreciated. Don't worry about suggesting what seems like the obvious, I'm pretty sure this will be something of that sort that I've over-looked to be honest so all suggestions are welcome.

Jon4h - I will check the HT leads are correct, the should be as I removed the dizzy cap with all leads still attached from the KR, put it in a bag and then re-fitted to the ABF complete. That said, you never know and it does sound like an ignition fault of some kind.

Gareth - I am sure I used the correct flywheel mark for the timing, the grooved 6 degree slot rather than the 0 degree dot, but I will make sure. It is easy to get that wrong I agree, done it a few times before!

Any more suggestions before I go out and get my hands dirty again?

 

Right, done a bit more tinkering, still having problems though.

I checked the HT leads, thought 3 and 4 the wrong way around at the dizzy cap so swapped them. Then I checked and reset the idle (with isv and breather disconnected) and checked timing, ok at 6 deg btdc with the groove in the flywheel.

Tried the car up the road and it seemed a bit better, not as quick but no rattley 'pinking' type sound. Progress I thought. Came back and pulled the plug leads off one at a time, this time number 4 wasn't getting a spark, the rest were ok so suspected plug leads.

Borrowed the leads and dizzy cap, all complete from my other 16v which works fine - fitted them and noticed that 3 and 4 were in fact correct to start with and I'd put them the wrong way by swapping them. Why did it run better with them wrong? ABF is surely the same firing order as a KR, 1-3-4-2?

With the known good leads the ran reasonably but still misfired under load and made the nastly rattling noise above about 2.5k rpm like it was pinking.

So, my thoughts are:

1. Should put some 98 ron fuel in to carry on, has 95 in at the moment.

2. Will get a new set of leads as definitely something dodgy there.

3. What is the rattling noise? Timing is correct, can't be pinking can it? Could it be a stuck tappet or sticking valve perhaps causing it to make a racket under load but idle relatively well? I think it's specific to cylinder 3 or 4 as when the dodgy leads weren't giving much of a spark to one of those it stopped as above, but with decent leads it does it?

Any tips or suggestions much appreciated - I'm confused!

Edit: Just reading some other threads and perhaps the noise is simply pinking - in which case, how do I sort it? Presumably 98 RON fuel and retard the ignition timing a bit? My other 2.0 16v (6A) runs 6 deg btdc with no pinking at all, but I do always use 98 RON fuel and it had a nice new P&P'd head so no carbon build up I suppose.

Any ideas? Can Anything be done with the mixture to help, presumably it needs to be richer?

 

doesn't the WUR mod richen the mixture.

definately put some better fuel in for starters.

 

Indeed - adjusting the WUR can richen the mixture if needs be, will be looking at optimising the control pressure in due course in that way. For now though, I just want to get it running reasonably which should be possible with a standard WUR I would have thought?

Decent fuel - yes, popped out for a can of Optimax / V-power or whatever it's called earlier. Alarmingly you can now get 6 of the stuff in a 5 litre can and it's not quite full!

Any more ideas? Will probably order a new set of HT leads next and then go from there

 

Another update on this, still having problems. I replaced the HT leads, dizzy cap and rotor arm with new ones and the car starts fine and idles pretty smoothly. Also now running on Shell 98 Ron fuel.

As before though, if you rev the car when stationary is sounds fine and revs well. If you try to drive it there is still the rattling noise around 3k rpm upwards which I think is pinking. If you change into second and try to get it to pull from low revs it shudders and strugles to go, wants to cut out.

The timing is set correctly, ignition side of things all seems fine (mostly new parts now!) so could this simply be an incorrectly set mixture? Firing order is definitely 1-3-4-2 as per the Haynes isn't it? Can't be different for an ABF to a KR surely?!?

How can I set the mixture up to get it running reasonably without a gas analyser? Is there a simple 'turn the mixture screw so many times' from it's stop kind of setting to get me started?

Help please! Want to get this thing MOT'd and on the road as the rest of the car is nearly finished now!

 

Stu, luckily for you I found the old 16vstall page info.... found a folder named website which had a 16v stall file in it... on my external hd, and opened it with flock and this lot popped up - sorry no pics.



This is G o o g l e's cache of http://www.btinternet.com/~gvk_motorsport/16valvestall.html as retrieved on 5 Oct 2005 05:39:41 GMT.
G o o g l e's cache is the snapshot that we took of the page as we crawled the web.
The page may have changed since that time. Click here for the current page without highlighting.
This cached page may reference images which are no longer available. Click here for the cached text only.
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This problem gets asked about 'quite a bit' on the forums - It applies to the mk2 Golf/Jetta 16v with KR engine

"My mk2 16v cuts out at junctions and idles terribly,I'm at my wit's end"

Ok, there are somethings you can check yourself at home.

If the ISV is working ,turn ignition on pos2 valve should *buzz*,

Make sure it isn't cogged up with oil deposits-either replace it or flush out with carb cleaner.. remove the brass air bleed screw and clean it also. If all that fails .........
Try cleaning out the inlet tracts of oil and the airflow flap.
If the engine isn't hunting when cold or hot, the CO is correct. 16Vs run
best at 2.0 % CO.

To achieve 2.0%, disconnect the famous "red lead" spade connector behind the coil (see fig:1 below) (after the
engine is at temp), pull off the breather hose and block the airbox hole.
Start the engine and the revs should plummet, if they don't, the idle valve
is shagged and you're idling off the bypass screw alone. Now, with the
engine running, turn the idle screw (fig: 3) up until you get 950rpm +-50.

If the idle wanders or is lumpy (engine visibly rocking), insert your LONG 3mm
allen key into the CO screw (fig :2) and turn it anti clock to weaken. Just prior to
the engine cutting out, turn the key clockwise in 1/8th turn increments
until the idle smooths out. Eventually, the engine should settle to a nice,
steady idle. This will be 2.0% or very close to.

Switch off and reconnect everything.

Take it out for a run and when you dip the clutch, the tacho
needle should gently fall to 1000rpm, not plummet. If after all that it's
still missing and rough, investigate air leaks around the inlet manifold and the various vacumn hoses

If you ever need to find the controller for the ISV it's the black box with 'VDO' marked on it that's clipped to the back of the ashtray or (if someones been fiddling), shoved behind the dash in a random fashion!

If you're really unlucky and the above instructions don't sort out your particular idling issue,check that the three senders on the end of the head, under the distributor are working, 2 of these control the ISV and the other is the temperature gauge sender - the senders are all the same so as long as your temperature gauge works, you can swap the wires to make sure all 3 senders actually make the temp gauge register, obviously if one doesn't work, there's your faulty sensor

WARNING -The sensors are about 20 from VAG so be careful whilst tightening them, they are tapered thread which means in simple terms that you don't wind them in all the way!

Thanks to Kevin Hayward for the original version of this posted on the Club GTI mailing list, many moons ago



Fig: 1 - red connector

Fig:2 - CO screw (req 3mm allen key)

Fig 3 - Idle screw

16v mk2 ISV circuit Wiring diagram - thanks to Kevin Yeoman.

* Menu

Site Last Updated Friday, September 05, 2003. 14:59:41 LOL!!

 

Brilliant - cheers Gary, I shall print that out, take it out to the garage and begin annoying the neighbours! Much appreciated!

Fingers crossed the car just needs a straightforward engine setup and this sorts it.

By the way - who'd have thought that Google would cache old versions of the internet?
I should have thought of something like that really, perhaps a bit early for my brain to kick in yet...

 

Good luck mate, it was more luck than judgement that I found it tbh.

 

Stu, have you used the KR ignition distributor, if not - you must... as the ABF dizzy is only used as a refeerence for the ECU IIRC.

Doubly check the inter-cam timing as your problem sounds a bit worse than 'just needing the mixture setting up'...

 

my KR did something similar.

turned out to be the coil

 

Gary - yes, used the KR distributor and fitted it to the ABF.

Were the symptoms exactly the same?


Right, yesterday I had another crack at this. Took the inlet etc. off and checked the inter-cam timing as suggested by Gary. I was sure it was correct but running out of ideas so thought I better make sure.

Pics here - this is with the flywheel, bottom pulley and top pulley all set to TDC:








These things are always tricky to tell if they're correct but I think that's fine, certainly not a tooth out in either direction I don't think. I compared the cams, which I'm assuming are standard ABF ones to a spare set of KR's I have and the lobes are all in the same position they would be with the KR cams in there.

Next, I put it all back together and tried setting the mixture as per the method Gary posted above. With the engine running and up to temp I can weaken the mixture 'til the engine cuts out, then richen it a little until it'll re-start and that's about the best it'll get. This still leaves a rough idle with the engine rocking a bit, and when put under load it struggles as before - still got a nastly clattery metallic sound when revved hard too?

Something definitely isn't right.... but what?!? It's really frustrating as it feels really close now but still undriveable!

I also tried advancing the timing a little past the usual 6 deg btdc mark to see if that helped but it didn't, still the same.

Any more ideas?

 

mine started off getting flat spots under heavy load. then one day it just wouldnt start. i was sure it was timing related or fuel issue.

i check everything, car was off the road for 2 months. banging my head against the wall. tried all the set up for the fuel. checked pressure. new injectors. temp senders, new plugs, new leads, best i could get was a lumpy idle and backfiring.

i was sitting there with my head in my hands. when i thought sod it. try the coil.

40 later. fired up straight away.

 

I noticed there were 2 timing marks on the flywheel...i had used the wrong one.
mk3 abf engine.
also my coil was running sh ite then eventually just died!

 

Ooh - that does sound similar then, I wonder if it's the coil on mine? Thanks for the reply, hopefully there is a way I can test the coil (will check Haynes) and establish if it's that.

I owe you a pint if a new coil fixes it as I'm starting to feel like you did, that I've tried more or less everything to sort it!

I'm definitely on the right timing mark but as above, could be coil related. Did a knackered coil cause you running problems too then?

I've never had a coil go on me before you see so didn't really suspect it, I assumed the leads were breaking up under load hence why I replaced them. I suppose the same could apply to the coil.

Anyone know how to test a coil then?

 

yeh stu coil sounds likely, sounds ignition based

Mine did similar, again!

Check the wiring to the coil as well, all number of things that could be broken.

the haynes manual diagram for the 16v was wrong I think, took me a while to sort it out. Ended up sorting the wires and it drove like a dream

could go check mine if you need?