49 f5 239 ba

T

towmater49

Junior Member
im having timing issues,when aligning bump on pulley to needle for top dead center,the number 3 plug is in compression stroke,the number 1 cylinder is no where near compression or exhaust stroke when pulley bump an the needle are lined up.could my timing gear be broke? any ideas please help.
 
after bumping over one revolution,number 3 is on exhaust stroke and number 7 is on compression stroke,when marks are aligned
 
i set number one cylinder at top of compression stroke,rotor is at number one wire,it backfires but needle and bump on pulley are no where close together.
 
Out of curiosity, when you crank it over with the cap off, does the rotor "jump" or does it go around smoothly? If it jumps then you could have missing teeth on the can gear. I would get it back on the TDC compression stroke, then see where the rotor is in relation to #1 cyl. It could have been installed off a few teeth or 180 degree+ off.
 
You may very well have a problem with the cam gear. They were made from micarta so the teeth will eventually give up the goat. I have an engine from a 8BA era truck and the old farmer tried to pull start it with his tractor with stuck valves. The gear was still good though because it broke the cam and drove one of the valve stems up into a cam follower. That engine was a b!tch to get apart.

First of all, you need to have compression on all 8 cylinders. If you have stuck valves, it's going to be very hard to tell whether you are on compression or 180 out. If you turn the engine to get compression puffing out of the #1 cylinder (front right side) then the dimple on the pulley ought to be very close (2 degrees BTDC) to the pointer. If it is way off then you will need to check the timing gears. The distributor rotor tip is usually pointing down to the 6-o'clock position (#1 firing) when mark is aligned. If the cam timing gets too far off, it may not get compression on many of the cylinders. If all the cam gear teeth are gone your distributor won't turn at all since there will be nothing to drive it. As was mentioned previously, a notchy rotation of the distributor will indicate some broken teeth on the cam driven gear.
 
Last edited:
How about a little back ground info. Is the truck new to you, did it run good before,
did the problem start all the sudden??

Bob
 
thanks for info rotorwrench, i do have compression all around, #1 cylinder is on top of stroke,rotor is at #1 wire, dimple on pulley is way apart from needle, the distributor shaft turns smoothly,doesnt jump or have slop.it fires but no start.thanks everyone for feedback.
 
Could the key on the crank snout be sheared, or missing, so that the pulley has rotated on the crank?
 
The distributor could have been repositioned to be near TDC or it was not affected by whatever happened. The cam timing is off for some reason and the cam drives the distributor. If the crankshaft marks don't align, it will not function correctly. It must have jumped some cam gear teeth for some reason or was not set up properly from the git go.
 
You must log in or register to reply here.
Back
Top