Timing marks (Hot headers cont.)

[cjshag]

1052575

I'm back at my Jeep trying to trace any mistakes or miscues. (See hot headers/lean carb.?) I was checking the timing marks and the position of the rotor button. My '80 Jeep service manuel describes the procedure to line up the marks if your engine was rotated while the dist. was off. I removed the #1 plug, manually turned the crankshaft until I felt the compression. The manual says to slowly turn until the TDC mark is aligned with the notch on the crank. Then place the dist. in with the rotor tip pointing to the number 1 terminal. My dist. is in place currently. When it is pointing toward the number 1 terminal, my notch on the crankshaft and the TDC mark are not even close. Are they supposed to be? That's what I take from the manual. Don't know if I'm on track or not? Any experts on this procedure?[addsig]

 

[MudderChuck]

1052602

Number one plug, left front as you are sitting in the drivers seat. Remove the number one plug and rotate the motor until you feel pressure with your finger (I use a compression gauge) turn the crank, usually about 1/8 turn, to center the notch on the harmonic balancer (crank) and the zero mark, on the timing marks.
Take a look at your rotor, if it is pointing straight forward, move the cables starting with one, on your distributor cap, to the front to align with the rotor. And install the rest in the firing order.
If the rotor isn´t pointing straight forward and appears to be one off. Start installing the cables (starting at one) where the rotor is pointing (length allowing).
If it´s more than one off (which I doubt) remove (lift) the distributor (after removing the fork and bolt at the base, watch the gasket), and rotate until you can catch the appropriate tooth. The teeth on the bottom are cut at an angle, so you have to kind of twist and push to get it to seat and you have to start off center from where you wish to end up.
If I now have you thoroughly confussed maybe CARDOC 123 can explain it better than I.

edited by: MudderChuck, Jan 29, 2003 - 07:51 AM[addsig]

 

[MudderChuck]

1052611

I was kinda rushed in my explanation (kids needed a ride).

TDC 1, top dead center, number one cylinder, top of the compression stroke, is the starting point for timing. On pre computer motors, the motor really doesn´t care where the distributor (rotor) is pointing, as long as number one,spark plug cable and plug, is firing pretty close to TDC 1 (crank notch lined up with "0" timing mark). Rough timing. They usually set up the distributor so the rotor is pointing a close as possible to the front, and the number one spark plug cable, is hooked up to the pole, on the distributor cap, that is pointing to the front (as a courtesy to the next mechanic). It can be adjusted by loosening the fork bolt at the base of the distributor (loosen only enough to turn the distributor with a little effort). And align the distributor pole as close as possible to where the rotor is pointing, connected to the number one spark plug cable.

Re-install the plug, re check your firing order 18436572 clockwise on the distributor and odd numbers on the left of your block starting from the front 1,3,5,7, and the right side of your block front 2,4,6,8 (as seen from the drivers seat).
Try starting the motor, if it doesn´t start, try turning the distributor about a half inch left, then an inch right, should fire up in there somewhere. Re-time the motor with the vacumn advance line disconnected and plugged, to about( 4-8 deg BTDC before top dead center) let the motor warm up and recheck the timing and time to spec.´s. Re-connect the vacumn advance line.
If you don´t have a timing light, in the next installment I can try talking you through, timing without a light (easier than you´d think).
I hope this is clarifying things for you. If it is confussing, I can try and simplify it some.

edited by: MudderChuck, Jan 29, 2003 - 07:49 AM[addsig]