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Post by eddypeck on Oct 17, 2014 11:35:39 GMT 1
For a while now I've had a problem building up.
It's on a 1986 VW Mk2 Golf 8v GTI with original engine on close to 190k.
It's the early one that runs on k-Jet system not the later digi one, so no ECU.
Started with bad morning start up, and has now developed into poorly running all the time.
It fires without issue, can't fault the starting. Just after that first burst of fuel goes in it won't maintain tick over or take any throttle without stalling. It's barely driveable till it warms up, but lots of revs and it'll get me off the drive and down the road, takes a mile or two before it's a little bit more settled and will tick over OK. But there's still a major hesitation and my MPG is down in the 20's, when I regularly get high 30's often 40's on the run I do.
Oh and I just put a fresh tank of Super unleaded in as I had had a couple of normal unleaded top ups recently due to getting caught out with no super available.
I posted on the Facebook page for the owners club, and also in the golf forum but thought I'd ask on here too.
Yesterday I had a suggestion of unplugging the 5th injector, but it wouldn't even start with the 5th injector unplugged!
I've checked for vacuum leaks, it all seems OK, I even changed the vacuum from the air box to the inlet manifold just for the hell of it as I had a spare bit of pipe.
The main breather from the cam cover to air box is also clean and clear, I did get a build up of gunk in here previously but that's not come back.
Reasonably new plugs, leads, cap and rotor, all checked and OK. Rotor had a bit of a build up but wire wooled that. Also noticed a lose spark plug, which is now rectified and obviously helped but wasn't the issue on it's own. More likely it's worked lose from the additional vibration of the engine not running smoothly.
It was also suggested I do a compression test, but I haven't yet and don't have a tester. Started looking on eBay, but what size/pitch thread do I need for the Mk2 Spark plugs?
So some further investigation last night led me to discover a 'more than expected' amount of oil in the air box.
The Oil was quite clear so not sure if it's diluted with fuel.... but no strong smell of petrol at all, and I did recently do an oil change so perhaps it's just still clean oil.
The oil appears to be coming from the inlet manifold and running down the tube into the air box, rather than the usual through the breather? the throttle body was coated in oil.
I'm not 100% sure it's from the manifold and not the air box end .... and I was looking last night in the dark. But it certainly appeared to be that there was more oil at the throttle body end than air box end. Made me wonder if the gauze in the top of the cam cover is clogged, which would be why the breather was dry... if so could it be backing up through the valves?
I'm happy with a bag of spanner and can undo stuff and replace the bolt on bits but I'm really no good at the diagnostics and understanding the workings... although I've learning a lot with this car in the past 18 months.
I have a spare panel filter and lower air box, so rather than fuss cleaning that was simply swapped. Also cleaned up the metering head, again all coated in a light covering of oil, and cleaned up the tube to the top boot and the throttle body. Did the best I could without taking too much apart in the dark.
So start up this morning was still crap, but maybe slightly better and overall running was better so the oil build up definitely has a negative effect, but obviously the oil build up is the result of another problem not the cause. It also explain why it's got progressively worse.
So, what puts oil in the inlet side of the engine? piston rings, valve seals, poor timing/mixture set up? There's no blue/grey/white coming from the exhaust and I don't appear to be burning oil.
Perhaps I'm barking up the wrong tree and the oil is a red herring..... any thoughts, very much appreciated. thanks.
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Post by Rhubarb on Oct 17, 2014 13:01:19 GMT 1
From your symptoms it sounds like the cold start valve/warm up regulator...The warm up regulator is bolted down the front of the engine block..
There are some checks you can do with the regulator with a multi-meter to confirm.
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Post by eddypeck on Oct 17, 2014 14:03:46 GMT 1
thanks, been doing a lot of reading up and coming to that conclusion too. Got a few things to test now,  I'm ticking 3, 4, 6 and 7 so far. The timing light I ordered has arrived today and I've just chucked a bottle of Wynns Injector cleaner in to see if that helps, but the WUR is looking like a likely candidate. I'll report back after a good look over the weekend. |
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Post by Deleted on Oct 17, 2014 15:49:28 GMT 1
First call with these was always supply pressure and volume !
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Post by Rhubarb on Oct 17, 2014 16:04:29 GMT 1
First call with these was always supply pressure and volume ! Yes I agree, but by the way he's described it the first and easiest thing to check is the warm up reg, bearing in mind it's age  |
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Post by eddypeck on Oct 17, 2014 16:21:13 GMT 1
Yes, but problem with pressure and volume testing is I don't have the equipment to test it. Therefore if I can rule out everything else and I still don't get anywhere then at least I'll be taking it to a professional with everything else hopefully taken care of, potentially saving hours of investigative labor charges.
If my trial and error diagnostics works then it's a bonus. I'd love to have the pressure test equipment and know what I'm doing with it, or have access to a handy, friendly local specialist. But I'm afraid I don't.
As rhubarb says there are some basic tests for the AAV and WUR so nothing to lose by going through the motions.
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Post by Deleted on Oct 17, 2014 18:53:43 GMT 1
Yes, but problem with pressure and volume testing is I don't have the equipment to test it. Therefore if I can rule out everything else and I still don't get anywhere then at least I'll be taking it to a professional with everything else hopefully taken care of, potentially saving hours of investigative labor charges. If my trial and error diagnostics works then it's a bonus. I'd love to have the pressure test equipment and know what I'm doing with it, or have access to a handy, friendly local specialist. But I'm afraid I don't. As rhubarb says there are some basic tests for the AAV and WUR so nothing to lose by going through the motions. The problem with the k jetronic was it was based on control pressure balance and manifold air flow , if either were out of spec nothing worked right, good luck with it, only way to learn is get stuck in , beware of screws that wont shift though , |
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Post by Deleted on Oct 17, 2014 20:30:24 GMT 1
First call with these was always supply pressure and volume ! Yes I agree, but by the way he's described it the first and easiest thing to check is the warm up reg, bearing in mind it's age Yes, but problem with pressure and volume testing is I don't have the equipment to test it. Therefore if I can rule out everything else and I still don't get anywhere then at least I'll be taking it to a professional with everything else hopefully taken care of, potentially saving hours of investigative labor charges. If my trial and error diagnostics works then it's a bonus. I'd love to have the pressure test equipment and know what I'm doing with it, or have access to a handy, friendly local specialist. But I'm afraid I don't. As rhubarb says there are some basic tests for the AAV and WUR so nothing to lose by going through the motions. The problem with the k jetronic was it was based on control pressure balance and manifold air flow , if either were out of spec nothing worked right, good luck with it, only way to learn is get stuck in , beware of screws that wont shift though , Without looking into it I am sure that the warm up regulator has a bimetallic strip in it that controls the fuel pressure? |
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Post by Rhubarb on Oct 17, 2014 21:58:08 GMT 1
Yes I agree, but by the way he's described it the first and easiest thing to check is the warm up reg, bearing in mind it's age The problem with the k jetronic was it was based on control pressure balance and manifold air flow , if either were out of spec nothing worked right, good luck with it, only way to learn is get stuck in , beware of screws that wont shift though , Without looking into it I am sure that the warm up regulator has a bimetallic strip in it that controls the fuel pressure? Yep that's the one...It controls the fuel/flow rate to the cold start valve, or 5th injector as it's wrongly called |
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Post by Deleted on Oct 18, 2014 15:07:47 GMT 1
Without looking into it I am sure that the warm up regulator has a bimetallic strip in it that controls the fuel pressure? Yep that's the one...It controls the fuel/flow rate to the cold start valve, or 5th injector as it's wrongly called MMMMM, not sure about that  I would want to know if the cold start valve was closing an not leaking !! should be able to do that with a bag of spanners  |
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Post by natedog on Oct 18, 2014 20:22:08 GMT 1
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Post by Deleted on Oct 18, 2014 20:23:23 GMT 1
Yep that's the one...It controls the fuel/flow rate to the cold start valve, or 5th injector as it's wrongly called MMMMM, not sure about that I would want to know if the cold start valve was closing an not leaking !! should be able to do that with a bag of spanners That's easy enough just tap the fuel pressure gauge into the pressure line of the regulator and observe holding pressure and pressure change from cold to hot |
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Post by Joepublic on Oct 19, 2014 11:22:03 GMT 1
My MK2 would start up from cold on 3 cylinders when the head gasket went, remove the plugs and using a torch compare the piston crowns, all should have a coating of carbon on the top, a clean piston crown (steam cleaned with coolant) suggests a problem. Do you have a strong spark at the plugs? Heavy mixtures need a good spark to ignite them. Has the fuel filter been changed recently? You'll find lots of car specific Kjet stuff here www.clubgti.com/content.php |
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Post by eddypeck on Oct 19, 2014 19:39:03 GMT 1
Yes fuel filter recently changed. Not great progress, but did make some new vac lines, just for good measure,  old on left.  Old on bottom  Made sure battery reported good.  And wanting to cover the basics I thought I'd check timing (I know it's not the main issue) but got hung up with this.  Dizzy is firmly stuck in the block, that typical corrosion when alley meets steel :-( Thanks for the rocco register link. I'll contact the seller, but most don't want to break engines for essential parts. Have been offered a complete engine for £70, which is worth that as on ebay someone's selling a wur on its own for half that. More to follow.... |
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Post by eddypeck on Oct 19, 2014 19:41:12 GMT 1
Ended up removing the rad fir better access, which gave me the opportunity to swap in the spare I had, old one was a bit of a time bomb  |
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I would want to know if the cold start valve was closing an not leaking !!
