Good day everybody,

has as anyone ever had their timing belt skip and throw your engine out of time?

I just put a 1uzfe in my Toyota pickup and am using megasquirt engine management system to run it, I had this engine running like a striped ape until yesterday. I was cruising along tuning my table, put a load on the engine, released the throttle and all of a sudden the timing on the crank went 30 degrees advanced and the engine started bucking/misfiring.

i limped it home and checked timing between the cam and crank, and they were way off. Crankshaft is stuck at about 30 degree advance, even with timing fixed to 10 degrees. I pulled everything apart to check the timing belt.with the crank at TDC, the driver camshaft timing mark is at about 5 o’clock, and the passenger camshaft timing mark is at about 8 o clock.

the pics I am referencing online show the timing marks are supposed to be at 12 o clock on both, is this right? The timing belt is tight, tensioner is holding tension, is there something else I need to be looking in to before I go any further?

i used a borescope to check the piston tops and I don’t see any valve contact, I am not sure what year engine this is, is there a serial number I can use to identify the year?

thank you for any input. I want to run a compression test, but the timing marks on the belt are gone, so I will have to buy a new belt before I do anything.

I will get a pic up this evening. It is an import engine so idk how similar it will be to the ls or sc.

i assume it is holding tension because I can only deflect the belt maybe 2mm, no slop I can feel anyway. But the tensioner does look in rough shape, so I don’t doubt it is the culprit.