[BioTex]

I just want some reassurance or advice to make sure my timing is set correctly.
Here is what I have. 258 w/100,000 mi. Doesn't use oil above what you'd expect. HEI w/vaccuum advance. New Weber DGEV 32/36. NO EGR, no computer, no vaccuum lines going anywhere except to the dist.
At curb idle (700 rpm and dist. vac. hooked up) I read 12 deg. BTDC. If I raise the RPM to around 1600, then the timing goes to 18. When I unhook the dist. vac. and plug it, the RPM drops a bit and the timing goes to 10 deg.
I rev the engine, and the timing goes to 12 to 13.
I run premium only, and this setting is just on the edge of not pinging under load. Does this seem ok, and could it be tweaked a bit better?

[jeepdaddy2000]

You want to be somewhere in the neighborhood of 35 degrees total advance. This usually means about 8 degrees initial with the vac advance disconnected. Revving with just the mechanical advance should net you about 18 degrees. Adding vacuum will give another 15 or so. These numbers vary a bit from set up to set up, but the final outcome should be the same. Also, the vacuum advance should be running ported not manifold vacuum.

[CJhollic]

Disconnect your vacumm adavance and plug it. Set your idle to 1600 rpms and time it to 8 degrees before top dead center + or - 2 degrees.. Return your idle rpms to 700. Hook your vacuum advance back up. This sets your initial advance.

Theoreticaly there should be no change when you pull your vacuum advance off, but a change of 2 degrees is no biggie. If it concerns you make sure your Weber linkage is set right so that the butterflys are 100% closed at idle.

It sounds like you are real close. As the previous poster said you want about 35 degrees total advance.

[Mike Romain]

With no computer, your idle gets set the old way, at idle with the vacuum line off and blocked.

Your 10 deg is right at the edge of the ping like you figured and if the fuel can handle it, then you are good to go. I don't think you can get much more base advance and not start pinging. I got one up to 11 once, but... I am running 9 I think.

Your timing advance vacuum sounds like it has draw at idle. This can be from an improperly set up carb mix which has the throttle plate too far open. Are you running rich at idle?

[BioTex]

Originally Posted by Mike Romain

With no computer, your idle gets set the old way, at idle with the vacuum line off and blocked.

Your 10 deg is right at the edge of the ping like you figured and if the fuel can handle it, then you are good to go. I don't think you can get much more base advance and not start pinging. I got one up to 11 once, but... I am running 9 I think.

Your timing advance vacuum sounds like it has draw at idle. This can be from an improperly set up carb mix which has the throttle plate too far open. Are you running rich at idle?

I am running rich yes, but might be because at a run last week, a club member who is also a respected jeep mechanic looked at my setup, and told me to take the vac. from ported and switched it to manifold. Seemed wrong to me, but like I said, he owns three garages in SanAntonio and Austin area. I still have it on Manifold, and it runs very well. It does ping under heavy load which is easy to do with 3.31 in the mountains. Also I think I'm running rich because I live at 4,600ft. elev.

[Bard]

Nice looking Jeep.
Are you running a FPR with the Weber? If not you may be getting too much fuel causing the richness you stated.

[CJ7VFR]

Originally Posted by CJhollic

Disconnect your vacumm adavance and plug it. Set your idle to 1600 rpms and time it to 8 degrees before top dead center + or - 2 degrees.. Return your idle rpms to 700. Hook your vacuum advance back up. This sets your initial advance.

Theoreticaly there should be no change when you pull your vacuum advance off, but a change of 2 degrees is no biggie. If it concerns you make sure your Weber linkage is set right so that the butterflys are 100% closed at idle.

It sounds like you are real close. As the previous poster said you want about 35 degrees total advance.

How are you guys setting your idle to 1600 rpm?

When I set my timing, I do as you just stated above, but I always seem to
have a hard time keeping the idle at 1600.

I usually either try to put something heavy in the gas pedal, or turn in the
screw on the carb that is for eliminating run-on after the Jeep is turned off.
(The one that contacts the carb body, and is usually set to 3/4 to 1 turn
after it contacts the carb body.)

Is this how you guys do it?

The problem I have is that I can use either of my methods, but after about
a minute or so, the idle will either kick down, or rev way up, and I have to
start all over again unless I am really fast with the timing light.

Is there a better method to use for this to keep the speed at a constant
1600 rpm without it changing on me?

Jim

[Mike Romain]

Originally Posted by CJ7VFR

How are you guys setting your idle to 1600 rpm?

When I set my timing, I do as you just stated above, but I always seem to
have a hard time keeping the idle at 1600.

You don't say the flavor of your Jeep engine....

Setting it at 1600 is for the computer controlled timing setups on the later CJ's and YJ's 258s. The computer controls the timing advance.

If you set a pre- emissions computer 258 like that, it will be a pig for running, the timing will be way too low. On those, the ignition module runs the timing.

I set up one YJ once like that and I just held the throttle steady and the light while someone else turned the distributor body.

[CJ7VFR]

My Jeep is a 1985 with the AMC 150 4 cyl engine. I have the computer
controls on it still, so thats why the 1600 requirement.

For the life of me, I just can't keep it at 1600 rpm. I can get it right on the
money by turning the one screw I mentioned before, but by the time I make
sure its really 1600 rpm, and then run to adjust the distributor, and then run
around the other side to point the timing light at it, the rpm's will either kick
down, or rev way up.

Maybe I should just do like you said, and get another person to help me.

I tried getting my wife to help once by holding her foot on the gas pedal, but
that lasted all of about 30 seconds, and then her cell phone rings, or a bee
flies in the window, or some other distraction comes along, and I am yelling
at the top of my lungs for her to take her foot off the floor!!

Jim