Correct Timing for 258?

Can anyone tell me the correct timing for a 1976 CJ5 with a straight six 258? And as long as we're at it, what the timing marks stand for on this engine since there are no numbers and I don't have a diagram.

thanks...

lj

 

8 to 10 degrees before TDC. I think its 2 Degrees per hash but don't quote me on that.

 

Oops, I quoted you!

Which way do they go? Is bottom hash advanced or retarded?

thanks...

lj

 

Bottom should be zero. With progressive advance as you go counter clockwise around the crank. One of the hash marks should either have zero on it or should be bigger then the others to stand out.

 

Thanks! I took it out to get it smogged yesterday and it failed as a GROSS POLLUTER (NO was measured at 2867 @ 25mph - 1224 is max).

They said my timing measured 14 BTDC which was what was probably causing the smog failure, everything else tested below limits.

Hoping to correct the timing and retest, but now I have to go to a test only station since it's been labeled GROSS POLLUTER...

lj

 

Glad I don't live in California. No emission or safety test at all in N.E GA. Next county south (closer to Atlanta) you have an emission test, but if memory serves me correctly, vehicles over 20 or 25 years old are exempt.R)

 

Are you sure there are no numbers becouse mine is labeled from 4...4...12 maybe its just dirty and you cant see the marks.

 

They had a 30 and over exemption here but just repealed it. So, 1975 and ealier are exempt, but 1976 forward will need to be smogged indefinitly. They are making it more and more difficult to keep older cars on the road.

lj

 

I borrowed a timing light from a friend and i'm going to take a look again this weekend when I try to adjust the timing...but the mechanic couldn't see any numbers when he was doing the smog check and he sprayed cleaner on it as well...

Does it sound right that if the timing is off by this much that it could be the cause of the emissions being so high?

lj

 

Yipee! Adjusting the timing solved my smog problem! After correcting the timing from 14 BTDC to the correct 8 BTDC, my NO numbers dropped from 2867 down to 534 ppm.

lj

 

6b for Manual Tran/8b for Auto

 

I can't find a timing mark on the pully to match the degreed tag that hangs off the timing chain cover. It doesn't a vibration damper at least that I can see. It is a double pully with the inner pully for the alternator belt and the outer one for the power steering belt. Today I hit it with a piece of sandpaper while it was running. Still don't see a hash mark on the inner pully. Anyone else with this problem?
What can I do about it?
Thanks

 

I think the only thing you can do is adjust it manually...it does help to know how the cap should be in relation to the firing order...let me know if you need a diagram, they are in the front of the chiltons. or I can scan one for ya...with the 258 it should look kind of like this
Block - 6 5 4 3 2 1

Dist - 2
6 4
3 1
5

I'm sure you already have but I would run my finger along the pully to make sure the notch isn't disguised by dirt or anything...hope that helps a little, take care, Steve

 

well the diagram didn't work so well but just imagine a your cap with the plugs in that rotation 2 should be closest to the block and 5 furthest