I tried timing my truck to the 6 degrees BTDC that it calls for. It runs like crap with no power at all at that setting, so I tried just playing around with it. I advanced it a lot, and now it seems to run pretty good, better than it did before I replaced the intake and exhaust manifold gaskets. However, I'm not sure as to whether the truck should be more responsive than it is. I really have no way of checking the timing, and I am assuming that the pulley slipped, cause the truck feels like it runs pretty well, so I don't think the timing is actually around 20 degrees initial. (Yes, I removed Vacuum advance when setting it, and the engine was fully warmed up)

So my question is, the pulley with the notch in it for setting timing (crankshaft pulley?), can it slip? if so, how can I put it back to the original setting so I can verify that my timing is in the correct spot?

Thanks in advance, and if you need any more info from me, just ask!

 

Any ideas?

 

I assume you mean the crankshaft dampener when using it to set timing.

I didn't trust the readings on mine either. What you need to do is buy a piston stop tool. If you scan the web you'll get a better description, but basically you replace a spark plug and then turn the engine by hand CW until the piston hits the piston stop tool. Mark the dampener, then rotate the engine CCW until it hits the stop. Mark the dampener.

Midway between the marks it top dead center.

It is the only way to know for certain how to set the timing with a light. I was using a vacuum gauge before and I was WAY, WAY off.

 

Ok, so doing that test or a makeshift version of it, will allow me to tell if the crankshaft dampener has slipped. So, halfway between the two marks should line up with the tdc timing line?

 

It should line up with 0° if your dampener's outside ring hasn't slipped

 

Aww Yeah, you guys are awesome! I did the test with a makeshift piston stop tool, and I figured out my timing notch is WAY off. So, in this picture you can see the three marks that I made, the middle one being TDC

Then, in this picture you can see the actual timing notch (far right on pic) and the rightmost mark I made on the pulley in the previous pic (far left on this pic)

So, after I got home from school today, I threw the timing light back on yet again, and I could clearly see my middle mark (I think) at 10 degrees BTDC. So, not bad for just timing it by ear with an exhaust leak Anyway, I adjusted it to 6 BTDC and after a very short test drive, I could tell it sounded different, and it felt a bit more responsive. Do you think the extra 4 degrees advancement would have been a large contributing factor to my poor fuel mileage (20l/100km or 12 mpg, granted it is freezing cold winter so I have to keep the choke closed for a while)

Thanks to you guys, I may have got it sorted out! One final question though, should I be concerned that the pulley has slipped? do I have to do anything about it?