timing

[drlogistics]

I was just wondering if anyone can tell me how picky the 302 is on timing. I've got mine back together after having a valve job and basically removing and cleaning/replacing everything on the engine. But now I just can't get it to fire. It turns over, I've got spark, and its getting fuel. So I suspect its not sparking exactly when it needs to. A friend suggested I find out if the cam has very sharp lobes which would require the timing to be just right. Anybody know?

 

[SturmTyger380]

You might have gone through the basics, turn the engine to top dead center and then make sure the distributor rotor is pointing to the number one wire. Make sure the wires are not in the wrong position on the distributor. I had two swapped on my M38A1 when I first started it after a rebuild and I was going nuts trying to figure out why it was running crappy. When I figured it out it ran fine.

 

[m1010plowboy]

Bob Kettler Tech tips, the TM's and SuperDave's hands showed me that the timing should be set at the Notch. Mine was set at 12 degrees when Dave got to it so we left it but I've been messing with it aggressively. It should fire through a wide range of timing.

I replaced 3 capacitors and 1 resistor in the distributor with new parts and it wouldn't run. Still had some spark but no fire. Put one of the old capacitors back in and I'm still running on it. As per the above, ensure the distributor is wired correct and the wiring direction on the coil is correct. Mine was wired backwards on the coil when I got it and may be responsible for capacitor damage but the truck still ran, wired incorrectly.

Keep us posted, nothing SuperDave can't fix.

Hope the pics work out, they are out of TM 9-8024 TO 36A12-1B-321.

 

[cmpman]

I just went thru the valve job/ clean-up ordeal a few weeks ago and ran into the same problem. 50/50 chance and sure enough I had my distributor out by 180°.

Pull the number one spark plug, turn over the engine until you have compression, and align the timing mark on the pulley with the pointer. Pull the cap, make sure it's pointing to number one position, and then turn the distributor counter clockwise until the points are just about to open. You can test the positioning by moving the rotor clockwise (making use of the centrifugal advance mechanism) to watch the points open. Close everything up, and the truck should run.

Once I (re) did the above, the truck fired right up, and on checking the timing, I was only out by a few degrees. I have never known the 302 as being a tough engine to satisfy with regard to timing.