Does Cam affect timing?
Advancing or retarding a camshaft’s timing from its original “zero” position causes the valve events to happen either earlier or later in the engine’s cycle. A camshaft that is advanced four degrees will cause each opening and closing event to occur four degrees of rotation sooner than before.
Does advancing a cam increase vacuum?
Your cam is tiny for a big engine. Vacuum should be a bit higher. Advancing it ‘could’ easily solve the problem. A few degrees cam timing can indeed affect vacuum, along with slight differences in both static and trapped compression, from the intake valve closing sooner or later.
Will you get spark if your timing is off?
No, if your engine has a bad timing belt, or timing belt slips, you could still have sparks. Timing refers to the sequence of which events are happening in an engine combustion cycle. Having bad timing can cause problems like poor engine running.
What is the position of the camshaft when setting valve timing?
Timing in the Camshaft. Rotate the crankshaft clockwise to 90 degrees after TDC. This will make sure all the pistons are half way down the bore. Now position the dial gauge so that it can read the lift of the inlet valve of number 1 cylinder from the top of the valve retainer (see left).
What will happen if the cam is off one tooth?
It will run really bad, backfire, and be hard to start. What about if the cam is off a tooth? Somehow when you lined up the dots on the timing set you was off one.
How to tell if timing mark is tooth off?
You could test for true top dead center on the #1 cylinder, then see if the marks line up. If you have enough swing at the distributor to bring the timing marks to line up with the engine running ,being a tooth off is not the immediate problem. Sounds like the mark shows more advance than it really is.
Why is the timing on my car not working?
It’s possible the timing marks aren’t right. The wrong harmonic balancer or pointer could cause this. The rubber in the balancer could be failed and the outer ring has shifted. You could test for true top dead center on the #1 cylinder, then see if the marks line up.
How to tell if the cam is advanced?
If the exhaust valve closes before TDC the cam is way advanced, if the intake valve doesn’t start to open until after TDC the cam is way retarded. This test is by no means a replacement for a degree wheel, but can be a quick visual during the initial diagnosis. Being off a tooth will also affect compression test numbers.