AFN Timing belt renewal

[gunman]

I'm after a bit of advice on fitting a timing belt to an AFN engine. I was just reading the haynes manual there and all looks straight forward enough until the refitting section. It says that you fit the belt to the crank sprocket, then the injection pump but you loosen the cam sprocket so you can adjust it when fitting the belt to ensure the teeth engage properly. OK, the cam timing is kept by the cam locking tool at the back of the head, but assuming the belt you're fitting has the same dimensions as the one you took off, surely you wouldn't need to do this?

I'd worry if I had to adjust the cam sprocket that I hadn't fitted the belt right?

Anyone else done this and did you loosen the cam sprocket?

[gunman]

Timing belt now fitted and a right bar steward of a job it was too.

I couldn't find the tdc mark on the flywheel and the haynes book of lies was no help either! The pics of the markers and inspection hole in the book of lies just didnt exist on my car. I set the cam and pump to the tdc marks and locked both. Marked up the crank and fitted the new belt. Turned over by hand and no valve collision, tried the starter and nothing but puffs of grey smoke from the exhaust. I must have been out a tooth but both cam and pump lined up fine and I had no factory mark now for tdc on the crank.

After about 2 hours of working at it I checked for a tdc mark again on the flywheel, this time I found what I suspected was it but when it lined up, the cam and pump were 180 degrees out. I advanced the crank a pit so all 4 pistons would clear the vales, set everything to tdc marks again, refitted the belt and the car ran fine.

Only thing I can think is that at some stage a spanner monkey had the head off and rather than set tdc by the marker, they just brought no 1 and no 4 piston to the top, assumed that was it and refitted the head. That would explain why I couldn't find the mark as it was 180 degrees from where I expected.

In the end I did loosen the cam bolt and lock the cam.

[Sleeper_Avant]

the crank will rotate TWICE to every ONE rotation of the Fuelpump and Camshaft

if it was 180degrees our on the pump and cam i would agree, but not if it was to do with bottom end/crank position!

its purely down to electronic setup of fuel pump that is the problem here,

and luck!

i have had 3 months of issues from an 8vTDI mk4 (ALH) Golf

couldnt time it propperly, VAG-COM said timing was way off, retarded it to max adjustment, still knocked like **** and no power under 3000rpm

turns out i had to forget the pump timing pin, knock the pulley back 2 teeth and slightly advance it from bolt hole centre.

the car now runs silent, pulls amazing and i have seen a 70.4mpg average on my 25 miles journey to work (up from 36!!!!!)

get it TDI Checker timed mate, trust me, you will get money back! (i save £20 a month now!! )

[Sleeper_Avant]

just to add, i bought this car with a snapped belt,
put a belt on it, timed it up atleast 20 times with locking plates and pins and still wouldnt go.

tried adjusting pump manually minimum 20-30 times still no-go (My best mates car)

compression tested it and it was 260psi accross the board (should be 500-550)

took the head off and no bent valves or broken hydraulic lifters........ very odd...........

built it all back up with everything new and Genuine from TPS,

compression tested again and it was still 260psi..........

turns out the compression tester was fook`d!!!

all that work for nowt.

pump timing solved this for me after months of head scratching, bahrstad lol

now it pulls like a teenage boy with a laptop and an empty house PMSL

[gunman]

This car was running well before the timing belt change, with the cam locked the pin fitted 100% in the pump pulley. The only issue I had was the lack of a crank tdc marker.

I know the cam turns half speed of the crank, and I also know the crank marker being 180 degrees out wasn't causing it not to start, just that when it didnt run I lost trust in my own crank markings but had nothing else to ensure all was timed right. I haven't got vagcom on it yet but will check the pump timing in the next few days.

Cheers.