K-Jet Experts - please help (latest update Pg 6!!)

ok the timing looks fine, maybe quadruple check piston 1 is at tdc by shining a torch down the plug hole, but with both crank pulley and flywheel lining up I doubt thats an issue.

compression check might be a plan, dry then wet test see how things are. but I'm suspecting now its down to fuel mixture or spark, pull the plugs out and make sure they're all spotless and leave it for a couple hours for any excess fuel to evaporate off.

wind the throttle screw right out, make sure air flap inside the air box is adjusted properly and if you push it down and release it springs up nice thru the hole. ideally hold it up to the light to ensure the disc is fully central in the hole, though if its never been apart should be ok. I guess you could put a bright light inside the airbox and see it in situ.

if you havent already done so do a full fuel injector testy as per my 16v guide, no fuel at rest, nice cones when lifted, similar volume delivered on all 4 etc.

pull fuel pump fuse and check all 4 spark plugs give you a fat white spark when earthed on the rocker cover while cranking, make sure the coil is correct and you have the right cap, arm and leads to match the coil as there are 2 types of plug lead on electronic ignition. check the plug lead connection type to the spark plugs. some press straight onto the thread on the end of the plug, some require the nipples to be fitted. usually8v are the first type. if any part of the ignition system is cheap make or unknown condition get new bosc/beru make parts:
AVS Car Parts - [The VW - Audi - Seat - Skoda Parts Specialist]

MK2 Golf bosch coils are available for around £30 on ebay, if you get one you need post-87 cabrio GTI plug leads, cap and arm to go with it. but if its got a bosch coil now then its probably fine, pretty much the most reliable part of any mk1/2

pull the 5th injector off the engine make sure it sprays when cranking, and doesnt spray if you disconnect the thermoswitch plug. the heater in the thermoswitch should stop the injector spraying after a few seconds cranking on starter, theres a chart for how long on this page:
https://vwts.ru/vw_doc/eva2/FU01/ch5.2.html

just to be 100% sure, firing order is 1 3 4 2 clockwise but I'm sure you are well aware of that

To check all that on the cam chart you need a dial gauge plus stand and a degree wheel but they do give you the valve lift at TDC which for the inlet is 2.78mm.
So, I think this is right, set No1 on the induction stroke at TDC and the inlet should be opening, work out a way to measure the valve lift, wind the engine back until the valve closes then forward again to TDC and the valve should have lifted 2.78mm, that will confirm the valve timing.
A piece of dowel resting on the follower with a reference point should work to measure the 2.78mm.
VW quote the figures at nil valve clearance, I don't know about Shrick, you would have to check.

 

rubjonny said

wind the throttle screw right out,

When you say throttle screw, do you mean the idle adjustment or mixture adjustment screw?

sorry idle screw, gives best chance of fire. idle will end up high once you get engien running but wind back in jobs done.

with mixture screw is a case of trial and error till it fires, if bits and pieces have been swapped in from other cars and its had full rebuild etc.

went thru same pain swapping metering head on my 16v years back, though I did have the advantage of knowing everything else was working 100% before the metering head swap I guess

I should probably clarify that most of the stuff is original, and this car was previously bulletproof reliable in the 20 years I've owned it.

Original bits:-
Metering head and airbox
Bosch ignition coil
Inlet Manifold
Bottom end
Dizzy

New bits:-
Cylinder head to stage 2, Schrick 276 cam (Mech lifter head, all shimmed etc by Dave Crissell)
Audi 2.2 throttle body and matching WUR
New Magnecor 7mm ignition leads
New dizzy cap, rotor arm (Bosch or Beru parts)
New HEL braided fuel injector lines
New Bosch fuel filter
K&N air filter

I have tried re-fitting the original dizzy cap, rotor arm, plug leads to see if the fault was there, but just the same.

Pulled the plugs, she's obviously been overfuelling

This is probably stating the obvious but some of the Audi WUR's had full throttle enrichment, they're deeper and need longer screws to fix, there is also a connection point for a vacuum hose, if that is not connected you will always run rich.
I've attached a photo but not sure if it will load.

Cheers Cedar, that's what I've got. It's been drilled at the back and control pressure adjusted as per the manual, and the vacuum is connected into the 2nd port above the rocker cover (normally fitted with a green plastic blanking cap).

Well I can't understand it now, if it just ran for a bit so you could get it warm and set the CO it would probably help.
Something that has never occurred to me before is that if you test the control pressure with one of these WUR's, I've got one, you need to do it with the engine running or  you won't have the vacuum and will read is the lower full throttle enrichment pressure.
Keep going It will not win.

nicci21paul said

they will not stink of fuel the problem is
no fuel pressure no matter if the timing
is 180 out it would bacckfire or make an
attempt simple internal combustion engine
i.c.i.e

……how can it be running rich if the original problem was no fuel getting thru???
Or has that problem been fixed? (its a long and winding thread)

Id put a known good original wur back on it.
the back fire up through the inlet manifold……you deffo got the leads on right? 1,3,4,2 clockwise? Sorry if I'm stating the obvious!. Over fueling usually ends with back fires in the exhaust. Under fueling in the inlet.

Where is the car?

Finally folks, I have a running Mk1!!

I checked the 5th injector and confirmed it was all good, pulled the plugs and confirmed a very healthy spark on all 4. I re-checked all the timing marks again, tried the static ignition timing method on cabby-info site to no avail.

Reset everything back to square one again, fully wound out the idle screw, fully wound out the mixture screw then back in again by 2 full turns as a start point.

First attempt to start, wouldn't fire again but another big pop in the inlet manifold. The ignition timing just couldn't be right, so started adjusting distributor until it fired first turn of the key but wouldn't run. Then kept tweaking the fuel mixture until she fired into life.

Let it warm up and made some minor tweaks but it'll need to go somewhere for proper tuning now.

You've no idea how delighted I am, thanks to everyone for all the help and advice, I literally wouldn't have got this far without the Forum.

So pleased for you, now you have it running and moving you can get the timing and fuel mixture spot on and get it on the road and enjoy all the hard work.  

Glad you fixed it.
I have the exact same issue and I am going insane. I am not a mechanic(not even close). When I left air flap manually the car will start and run. I have a couple of questions.
Did you replace the coil?
This may seem daft  but how do you adjust/remove  the idle screw? Never touched it before so not sure

 

Removed idle scew, cleaned and put back. Hey presto car starts. Pops and farts but running