I shredded my supercharger belt a few weeks ago after replacing my water pump and alternator

But now after getting the replacement, it keeps popping off. While the car is idling it seems to be fine but it's whenever I open the throttle that's when the belt pops off. I've made sure the belt is as tight as it should be.

Now I was looking at this diagram below for the idler pulley and tensioner


Is there any adjustment (forwards/backwards) to the idler mount bracket (number 8 in the diagram)?

 

I just replaced my supercharger belt, from what i know you have to loosen the pulley and turn #4 tensioning rod to adjust

 

Just a thought, the pulley for the water pump you have replaced may have been installed too far on or not on far enough. This would cause a misalignment. Something to check.

 

Thanks for the replies guys.

Seems like I've fixed the issue I was having. I took off both idler pulley and tensioner brackets. For some reason my tensioner just had a combination of different size washers to keep it aligned with all the other pulleys to make up for #2 in the diagram. Who knows what the previous owner did, just glad I was able to get it sorted out. As for the idler pulley bracket, there is slight adjustment you can play with to move the bracket/pulley about a quarter of an inch forwards/backwards to keep it aligned with all the other pulleys.

After making these adjustments and trying to eyeball the correct alignment, I haven't had any issues with the belt popping off.

Now if only I had known I could get the factory Jaguar supercharger belt from aftermarket suppliers but with the same exactly belt specifications, I wouldn't have had to spent $55 on a single belt.

 

Glad you're sorted mate, happy motoring.