Club 80-90 Forums

Connected Vacuum = 9 secs
Disconnected = 7 secs
(bit weird - I wasn't expecting it to be slower connected up?)

TBH, ot shouldn't make much if any difference as vac advance is only relevant when at less than full bore.. if you went flat out, then vac advance wouldn't be doing anything, its really for part-throttle econmoy..

So investigate centr adv with a strobe (a quick and dirty crude check that it's at least working isn't difficult; estimating quite how much, well that takes a bit longer)

YOu have to establish as of priority the baseline:-

1) Type of cyl heads

2) Take compressions across all 4 cylinders, do that thoroughly once then repeat, to give a good average figure for each cylinder... be consistent with method for each cylinder.

Cheers Harry,

Strobe to be borrowed later in't he week.

On 1)Type of cylinder heads is proving elusive. As the manifold is freshly sealed up - new gaskets etc to the heads I am wary of whipping it off to check the size of the inlets - is there anything visible on the outside that I could look at

On 2) - will see if I can get hold of a compression gauge and have a go.

I'm no expert on WBX's, esp 1.9's but there must be a way?? Keep asking

Someone should have a comp tester nearby, surely? Tame local garage? It's not soemthing they'd be using every day, that's for sure. They aren't actually a lot of dosh in Halfords or some GSFs carry tools at good prices.

Halfords £18-99

...think I will get shot (by the better half) of I buy more (specific - and a compression tester is pretty specific ) tools and/or spend much more time on the van at the mo...(we have a baby due Friday reason for me trying to get this sorted b4 then).

Have arranged to borrow one locally tho - thanks Jaylo....and a Strobe - thanks Jon at work....

This is what you should be referring to then...

https://club8090.co.uk/wiki/Pe ... nce_curves

Update.....am I going mad or is this rotor arm (and therefore distributor) back to front?

(Bear with me - this is the level of mechanical noddyness you are dealing with here)

[IMG:800:600]http://i281.photobucket.com/albums/kk21 ... /Rotor.jpg[/img]

The moulded bit on the rotor arm is fitted into the cut out on the dizzy shaft - the contact on the rotor arm is facing AWAY from the notch 180 degrees on the dizzy (you can't see the notch that well on the photo - but it is in the usual place - as shown in the haynes) . I have rotated the engine so the v on the pulley is in line with the crank case centre as in pic.

The pic in the Haynes suggests the rotor arm should be contact nearest notch - when v is lined up with crankcase split.

If I am not going mad - and the garage has fitted the dizzy 180 degrees out - how straightforward is it to turn it around (is it just take rotor off, spin engine 180) then replace.......? ) and would this explain my poor running - and what have I done running about like this............

Put the cap back on .... looking from above the lead at 7 o'clock is bottom left plug, 11 o'clock is top left, 1 o'clock goes to bottom right and 5 o'clock goes to top right(i.e. these leads cross over). If the engine's set up 180 out the leads sometimes don't fit.

It's also got a 2.1 water pump (note the oil cooler/warmer spigot blanked off) that implies corners cut to me.

Ian.

My thoughts on this (and looked back through thread but found no mention) are that you should establish for sure that timing is correct using the strobe. If its not correct, depending on which way its swung, it'll either be sluggish or pink like mad. You may have the former scenario so check with strobe to be sure.

Turn the crank another 360 degrees and see where rotor arm is pointing then, it'll be where you expect it, i expect..

1 turn of crank = 1/2 turn of dizzie, so that prob. isn't firing position for No.1 but vac unit looks in the right place

Dont no if this may have any relevence to your performance problem.But i had a VW new 1600cc fitted to a van but was sluggish top end.The timing and carburation was checked okay .This was years ago where you could get a new Aircooled engine from a VW main agent and fitted.I kept returning the van under warrenty for the problem to be diagnosed/resolved .The sluggishness was due to a tight crankshaft in the engine assembly .

mikey9 wrote:I

So my latest thinking (pleeeeease contradict/correct me if I am guessing wrong or making things up) is that there is either:

1. A leak in the tube from Carb to Vacuum (will have a play later with air and a bowl of water) and then renew all the hose bits on it.

2. A failed/failing diaphragm attached to the dizzy

3. Something further down the dizzy - like sticking weights etc..

4. Something completely different ..........like DF heads

Please excuse me if I have gorn orf half cocked so to speak but I think you would be in a much more knowledgable position if you could actually see what was happening. A good way to achieve this would be to observe the ignition timing while the engine is running by using a strobe light. If you have a brave or foolish accomplice he/she could sit in the back with the engine cover off while you did your Louis Hamilton bit. Just a thought...
Cheers
Ken

This was years ago where you could get a new Aircooled engine from a VW main agent and fitted.I kept returning the van under warrenty for the problem to be diagnosed/resolved .The sluggishness was due to a tight crankshaft in the engine assembly .

.. sounds like it was also way back when VW took customer satisfaction seriously too. That's a rare one!

Thanks guys, am building up to the strobe/timing attempt - embarrassed about the 2 revs of the flywheel to one of the dizzy mistake ...dooohhhhh (I blame the sleep deprivation of fatherhood and the excitement of finding something that didn't look like th epic in the book!)

Bit busy with 2 year olds birthday party - cake just finished (by me), wife 2 days overdue with second - and a bit nervous about cocking up the timing and making it worse or worse by rushing it.

If it all stays quiet on the birth front - then will try to check the timing and whether the advance is actually working tonight..

Otherwise it is booked in Friday with a newly found LOCAL T25 specialist and garage owner who has one himself......hoorahh!!

I have now spent a little time getting my head round the whole timing thing and have found the following:

170mm pulley wheel
85mm radius
Perimeter = 2"Pi"r
=2*3.142*85
=534mm

360degrees
so 1degree = 1.48mm
5 degrees = 7.4mm
7.5 degrees = 11.1mm

...so why am I calculating this.....

When i worked out the rotating direction was left to right (at the top of the pulley) and that the notch on the rear edge was to the LEFT of the shallow U on the rear edge of the pully - I checked the other pulley I had in the garage (not sure if this is off my old engine or the replacement).

First PIC is the pulley on the engine - notch to LEFT of (a bit indistinct on photo but clearly there) the U on the front rim. Engine running badly was timed to this.......

[IMG756]http://i281.photobucket.com/albums/kk21 ... _ONVan.jpg[/img]

Second pic is the spare one in the garage - notch is a bit indistinct but is to the RIGHT of the U on the front rim

[IMG756]http://i281.photobucket.com/albums/kk21 ... OffVan.jpg[/img]


I suggest the second one is correct - as pulley rotates - the notch (5 deg BTDC) should be approx 7.4 mm before the TDC shallow U. The pulley on my engine has these marks the other way round......

I have now tested the vac advance (advances at revs), and the centrifugal weights (advance) using strobe.

At 850RPM - Vac disconnected I timed to 7.4mm BEFORE the TDC mark i.e. to the right looking from the back (or as close as I can measure to the middle of an indistinct U - with a tape, in the rain/dark, under the fanbelt ).....and.....it bloody works...

I have power, well as much as LPG plus a suggested 78BHP in a high top offers....

Chuffed to bits that thinking it through and calcs with a pencil still works it out.

Still interested to understand why the pulley wheel can be so wrong - as it must have a key notch like the one I have in the garage....?

Thanks for bearing with me on this one - your replies/encouragement - and not taking the p8ss did help...

Nothing quite like rationalising it out the way you think yourself.. 10/10