Hi there
If somebody would be able to help me with this prob i would be extremely greatful as i'm a bit stumped!

Basically the cambelt slipped on my 89 240GLT B230E when the car was at idle, stalling it. Tried stating it once after that but realised it wasn't gonna fire. took the top belt cover off and could see the edges of the cambelt near the crank pulley were shredded. belt hadn't actually snapped though

so, i decided to take it all apart on the offchance of damage (my haynes seems to refer to the B230 being an interference lump). there has also been a fair amount of oil and gunge all over the belt covers for a while now, which i assumed may have been a leaking cam seal but could never be bothered to do anything about! i know, i know, i'm afraid i am very lazy! ha ha
so, i figured taking the head off would give me a chance to change gaskets, clean things up and replace the water pump o-ring as theres been some coolant leakage for a while.

anyway, to cut to the chase a bit, valves looked ok, all seemed to be seating fine so all seemed ok there. turned the crank so that no. 1 and 4 were at TDC and slapped the head back on with a new gasket and so the timing marks on the top of the cam sprocket and belt cover were lined up. so, no probs so far with both top and bottom end at TDC on no. 1.
retorqued the head bolts up to spec and replaced manifolds just leaving me with timing belt installation. i don't know if i did the right thing but decided to largely ignore the painted marks on the belt as they didn't seem to correspond with the timing marks.

now, with cam and crank at TDC i just had the intermediate pulley to worry about. this is where my confusion began. seemed obvious to turn the pulley until the rotor arm pointed at where the no. 1 HT lead would sit on the dizzy. however, when it did the timing marks on the intermediate pulley were 180 degrees out. it seemed to me that for the pulley timing mark to correspond with the belt cover timing mark the dizzy rotor arm would be pointing to no. 4. errr.............ok

suffice to say i was a bit confused. anyway, this is probably where i became stupid but i decided that if the rotor arm was pointing to no. 1 then all must be ok even though intermediate pulley marks 180 degrees out.

so, i tensioned the belt, put it all back together and decided to give it a twirl. i turned it a few revs on the crank by hand just to make sure the cam and crank were still on TDC. when cam lined up on the marks (and both cam lobes pointed up at roughly the same angle) crank was lined on 0 degress. fine. obviously this was only every 720 degress of crank rotation.
so, i tried to fire it up..............err
it cranked very briefly than backfired like a good un!!! suffice to say it scared the crap out of me
i've tried it a couple of other times after i realised the vac pipe had popped off the dizzy but same thing. a little bit of turning over and then a big backfire.

can somebody please help cos i'm really not sure whether to remove the belt and spin the intermediate pulley 180 so the marks line up. i just can't understand how that can be correct as the dizzy rotor just wouldn't be in the correct position (unless i swapped the ht leads round i suppose but that certainly wasn't how they were before i took the head off)
i'm probably being really stupid but i'm gonna blame my stupidity on the hateful british weather numbing my braincells and paths of logical thought.....well, if you can't blame your problems on anything else but yourself then what can you do!
really really really appreciate any thoughts or opinions
thanks very much
James