Thank you for all the help. I got it running.
This 91 has the sprocket gear on the crank, the one that the crank-pulley slips onto, installed 180 degrees away from the conventional mark. I carefully slid it from notch to grove so I know I got that sprocket gear on correctly.
This has been the first time I did the timing belt on this car and I'll have to make a note; I used a straw in cylinder one to tell where the top was. I've heard of this sort of thing happening on the cam but never on the crank.

 

My buddy had the center crank pulley bolt come loose while driving once, after we did a timing belt job on his '95 940. My fault - I used my 9-year-old, completely worn out universal joint on my impact gun - there was so much play in the universal that it absorbed 99% of the gun's energy, and failed to tighten the bolt. Surprisingly, it took a week before the crank pulley backed out, making the engine sound like it was about to grenade. He checked things out when he got home, saw the loose pulley, fired it up to get it in the car port, shut it off and it jumped time.

I ended up having to replace the crank pulley, and the timing belt drive gear. If I remember right, there was a key in there to keep the timing marks aligned properly, and it had sheared partially.

Lesson learned there - ALWAYS double check that bolt with a breaker bar after using an impact to tighten.

 

how do I correct a problem like that? I want the crank to be in it's usual position and believe it's may likely be necessary for perfect timing.
I know that on the crankshaft, the sprocket gear is on the groove, and the pulley has the sprocket tab into it's notch. Did perchance somebody have the oil pan off and work in confusion? It seems an unlikely coincidence that the actual tdc is at a mark embossed zero on the timing belt cover; some mechanic may have that was the mark? (This embossed zero is about five degrees clockwise from the zero degree timing mark.)

 

"not unless the pulley has spun on the crankshaft." Is there some pulley I don't know about? Like I say, seems like only possible if I am wrong (again) and the gears aren't on correctly and the pulley is skewed. Or, somebody adjusted something.

 

The little nub on the crank sprocket can get sheared off, if the pulley got loose somehow and was allowed to spin - that's why we ended up replacing both on my buddy's 940. Probably didn't need the pulley/harmonic balancer, but we bought one anyway just to be safe.

 

The timing marks on my Volvo 1991 240, the one for the crank, is not at the specified mark:
1) My sprocket that goes onto the crankshaft is fine and the groove inside the sprocket is corresponding with the crank tab,
2) the sprocket outer tab is into the pulley notch.

Status) Yet, I have the have the sprocket tab pointing at around six o'clock instead of the usual eleven o'clock (roughly stated times to indicate position of sprocket tab).

How could this get messed up? I checked these marks three times but is my being wrong the only reasonable answer? Pierce, have you ever heard of this being adjusted before or do I sound like I am mistaken for sure?

Even though I got it running it is still a bit rough, way better than before, but not like my other 240s, seems out of time.

Thanks,
Matt

 

Once you set all the marks, and you are at TDC COMPRESSION on #1 cylinder, you just need to make sure they're all set - once you rotate the engine, the marks on the belt will never line up again.

Well, maybe they would ... but you'd have to probably rotate the engine 30 times by hand.

From memory, the crank mark (was on the washer on the 940) needs to be lined up with a mark in the plastic cover (the one behind the belt, not covering the belt - roughly noon from what I recall). The cam mark needs to line up with the mark on it's plastic cover too (same way basically - behind the belt, also at noon), then the oil pump gear lines up to something else behind it that I can't recall at the moment ... I remember it being hard to see, but once those are all set, just rotate it by hand to make sure everything moves like it should ... 2 rotations will bring the marks back (not the marks on the belt though - once moved, those will not line up).

Hope I didn't make it more confusing for you. AND, I have a 940 B230 naturally aspirated - don't know if the 240 is the same or not. I'm new to Volvo's,, but have worked on cars since I could stand up on my own without crawling.

 

Hi Smithsonite, I get that you have a 940 and have the timing mark for the crank tdc to be with the pulley mark at noon. I'm glad to know this is the way; there are two possible locations for the tdc crankshaft mark.
Mine is post 1991 when I accept Volvo decided for relocating from the eleven o'clock position of the sprocket gear to the noon position of the pulley mark. I guess I will purchase a more modern book, mine only covers 240s until 1986. I can't imagine why they changed it.
Regarding the crank pulley coming loose, I understand that is more of a problem with these post 1991 240s too. It is only recommended to be tightened to something like 60 ft pounds or something like that. I tighten mine way tighter because I've also witnessed pulley and sprocket damage from a loose pulley. I always pull the radiator so I can get in there straight with my impact gun. I don't have the Volvo tool for holding the pulley or I'd use a breaker bar and save myself that unpleasant task for me to pull the radiator.

 

You know how the sprocket gear on the crankshaft has a notch on the inside and a tab on the outside, now I wonder if it is the notch that is supposed to be lined up to the eleven oclock mark on the block?
When the tab of the sprocket gear is lined up to the eleven oclock block mark, cylinder one is at or near the bottom. And as I know now, the pulley mark aligned with the noon mark on the cover is tdc. Does this also correspond to the crankshaft sprocket notch being aligned with the eleven oclock block mark? If so then everything stayed the same and I just used the wrong mark on the sprocket, specifically the tab instead of the groove.