'94 Timing Belt

[sunmicroman]

Just a question on how to line up the cam sprocket and crank sprocket on my '94 Metro in order to properly time the engine. The book I am using talks of aligning the "marks" but there is no diagram. I did notice a dot on the camshaft sprocket as well as on the crank sprocket. Are these the timing marks and if so how should they be lined up? Thanks.

[sunmicroman]

OK, got them lined up and everything put back together as best as I could. Now the engine cranks over very strangely and won't start at all. What else should I check? It ran great before I replaced the timing belt.

[Crvett69]

might want to check again and make sure you got the marks right, the dowel pin on the cam should be straight down and the line on the gear should be straight up and line up with a mark on the metal plate behind the gear. crank keyway should be straight up and there is a mark on the gear that should line up with mark on engine behind it

[sunmicroman]

Thanks for your help. That's what it was. I guess I used the wrong notch on the cam sprocket the last time. There actually are two (named 60 & 80). This time I looked for the camshaft dowel pin being in the down position and that lined up with the "80" mark against the metal plate behind the gear. It also was a lot easier to install for the belt as I wasn't fighting the valve springs like I did when I used the "60" mark (I had to have my son hold the gear with a tool as I put the belt on the sprocket so it didn't move when I used the wrong "60" mark. Why are there 2 marks anyway?).

[Crvett69]

im not sure what the second mark is for, anyone?

[gillesseattle]

I confirm for the tho notches (60A and 80C)
I just have the same problem and I am going to try! I had lined up the 60A notch on the cam gear just before and it didn t start as for sunmicroman
Thanks all!

[frets14]

My understanding is that this sprocket is used on both the 3 cylinder and the 4 cylinder engines. One mark is for the 3 cylinder and the other is for the 4 cylinder models.

[moonlightserenader]

I have a similar problem, but the sprockets are lined correctly. I can start the car, it sounds sorta funny while it idles. When I put it in gear and start to drive it slows and dies. I just replaced the water pump. I thought it was the battery or Alt because the lights dimmed etc. But both check out ok. only other thing I undid to put the pump in was the timing belt. Checked the sprocket alignment, s'okay. could it be the tensioner pully? And if so, how do I adjust?

[John Holst]

Many thanks to Sunmicroman and Crvett69.

I checked the Haynes, Motor, and Mitchell repair manuals. All three of them show diagrams for alignment of the timing belt that use the "dot" on the spoked-style CAM sprocket as the mark that should be aligned with the notch on the valve cover. All three of of these manuals are wrong; They obviously reprinted the same incorrect data from GM. I set my timing belt according to these manuals and, like Sunmicroman, found myself with an engine that would not start and sounded "odd" when trying. The timing is 120 degrees off in this configuration. (Actually, since the ignition timing is derived from the CAM in this engine, it would probably work if things were off by 180 degrees, so maybe we were only 60 degrees from success.) Like Sunmicroman, I too found it odd that one should have to fight the valve springs when installing the new timing belt. Once I set the timing using the groove at the end of the "80" spoke as the timing mark, the engine immediately fired up and purred like a happy cat.

Your posts, with their accurate descriptions, really helped me. I, along with some of my fellow engineer/car enthusiasts, had racked our brains for a couple of days with this problem.