Timing marks. abf

[sleeper16]

does the timing mark on the flywheel only line up at tdc of No.1 or does it do it on another as well poss no.3? just i ask as done a few bits on the golf including head gasket and cam belt and it wont start got the flywheel timing mark at lining up put then cam pulley is 180 degrees out. i was really careful not to move anything in the process and turned everything over by hand as i built it and before starting.


Cheers

[danny_p]

timeing mark  on flywheel  is no 1 TDC     as with any inline 4  engine another piston will be at TDC as well iirc it'll be cyl 4.

when you turn the cranck 1 revolution  the cam timeing mark will be 180 out as cams are driven at a 1:2 ratio   so from TDC  2 turns will bring the camshaft sproket back to TDC  and it'll line up with the flywheel again. 

if you need to make adjustments,   wind the engine 90 degrees back from TDC  that puts all 4 pistons midway,  pop the belt off  turn the camshaft sproket to its tdc mark and then rotate the cranck to TDC and put the belt back on, 

then turn the engine two turns by hand ( one compete rev of the camshaft sproket )  and the flywheel mark will line up again

[sleeper16]

cool after reading that i realized it was the most stupid question iv been out there all day and couldn't see for looking. what i meant was:

at no1 tdc the mark on the flywheel lining up and then when the crank is turned for example a turn and a quarter and number two is at tdc will this mark on the flywheel line up with the pointer.  or does it only even line up when number 4 and number one are at tdc


and then realized the flywheel is fixed to the crank so will always be in the same position 


so if i set the crank at tdc (turn it anti clockwise 90 deg) then put my cams at tdc so the two dots face inover then this should be it timed right? theres not a sensor or something that say no4 should be at tdc for combustion instead of exhaust etc?


cheers for the patience with that ridiculous question

 :embarassed:

[rubjonny]

1 and 4 will always be at tdc as you say, and as danny says the crank will turn twice for every single rotation of the cam. as long as the crank dizzy and cam are at TDC all at the same time all is well!  The dizzy on the abf is fixed so its less of a worry, but it can be fitted 180degrees off so check the rotor arm points at the notch in the dizzy housing when the cam is at TDC.

[danny_p]

best off with the cranck away from TDC  this means the pistons are no where near the valves when you are playing with the cams. ( it's more just good practice but a ghood habbit to get into as that way it near as dammit inpossible to accidentaly damage anything )

line the marks up on the cam sprokets,  and the mark on the cam sproket will line up with the arrow in the rocker cover.  bring flywheel to TDC and belt on  job done


in answer to your other question the cranck has missing tooth wheel on it but that can only tell the ecu where it is in any one turn  as far as it's concirned no 1 TDC  is no4 TDC  they identical to it.   the nice thing with the 16vs is the dizzy is driven off cams  so it dosent matter where the intermediate shaft is and the timeing mark for the cams puts the dizzy close enough for it to run.  on the ABF the sensor you mention dose exisy but it's in the dizzy it sends a singel pulse to the ECU ( hence why it won't work with k jet ) every two cranckshaft revolutions this tells the ecu where the cams are that it's starting a two revoluion cycel it then runs off the cranck position sensor.     

if you have starting problems  once properly timed up check the cranck postion sensor   it's  about the only sensor that will stop the running on it's own

[sleeper16]

cheers having trouble getting the timing set up right i haven't got any pulley locks. and i know vw say to fit the belt anti clockwise to get rid of the tension between cam pulley and aux pulley but i cant i can only get it one tooth behind then as i tighten the tensioner up it moves the crank to compensate for the slack on opposite side.


iv got it to about 1/4 of a tooth out  by setting everything to tdc and then moving the cam pulley advanced by about half a tooth and then putting belt on and tensioning that way when the crank moves it pulls it more into line, if that makes any sense


cheers

[danny_p]

don't worry about the itermedieate shaft pully.     

put the cranck tdc feed the belt round it over the intermedieate shaft then pull it resonably tight as you offer it up the cam pully  then just nudge the pully forward or back a bit ( whitchever is closest) so the belt will fit, then put some tension on with the pully ,   spin the engine over a few times by hand then check the tensioner again and adjust if required then your all done 

[sleeper16]

ahh what a nightmare finally got the two timing marks lined up and checked the mark on dizzy and that at no1


but still wont start it tries and struggles and almost starts but then stops

will check spark and fuel again

cheers for that info

[sleeper16]

had a good look over it and getting spark and fuel so thought id check the timing again and there it is quarter of a tooth out no iv been messing around with it and thought, how can my timing be quarter of a tooth out when there is no variables?

the teeth on all pulleys are set  none of the pulleys have been detached only the tensioner which goes to a set tension determined by the alignment marks there fore the only change is the belt and as the teeth on this cannot be moved the timing cannot be a fraction of a tooth out it would have to be 1 complete tooth out unless the belt is the wrong size or needs to stretch

is this correct or am i missing something drastic?


if so what should i do put the belt in hot water? or do i need to take it all apart again and get them to replace it?

[danny_p]

you actualy trying to be to presise,  if the marks lineing up just 1/4 of a tooth out move the pully so it lines up and put the belt on there and that will be right. the timing marks very rarely line up exactly the is allways a bit play.  or a bit more if the heads had a skim.   

cambelts don't strech there desinged not to  what will happen is it will bed in to the pullys after a short while whitch once this has happend the marks will mor ethan likely get closer,  the spring loaded tensioner will keep the tension constant.     

when vernier pullys are for when you start gettign presise on performance engines but it's actualy very common to offset the timeing a bit anyway.