setting timing correctly

[1986cj7]

Set timing to 12 degrees btdc at 1600rpm like sticker at rad says runs like a champ now. Just a question, where to find this info if sticker is not there. The chilton says 9 but doesn't say what rpm. Others say 9.5 and still others say 8 but don't say what rpm. I even checked the timing after setting to 12 and it was 6 at an idle, idle on mine being 750. Now after tinckering with the timings I also had to adjust the carb a little, because I had been tinckering with it before setting the timing back to 12.

 

[MN CJ7]

1982 to 1982 Jeep FSM is the best source and covers it fully

the 1600 rpms is true for Computer Controlled engines AND Carter Carbs and Full Sensors.... 1982 to 1986 Jeeps (1981 for calf)


If any of the pieces, computer, carb, O2, knock sensor are not working properly... the engine will be in limp mode and not work properly. I also guess few of us have all these pcs working as they did 30 yrs ago..

 

[Sasquach]

The Chiltens manual is a generic representation on many years not to mention 49 state and Ca. settings. For best reference get a FSM for your specific year vehicle. Wear on gears and timming chain will have an effect on swings in settings too.

 

[1986cj7]

Sorry just read a reply here it is.


Seems there is a bit of confusion on how to set the time on a jeep CJ

The "COMPLETE" and fully functional "COMPUTER" controlled jeep CJ's will be timed at 1600 rpms as 1986CJ7 has said...

If the computer, computer controled carter carb, and all the sensors and not there and working..... then do not time your CJ like this, at 1600 rpms... The AMC Computer can only take out or lower the amount of ADVANCE.... it was timed at 1600 rpms, .... used the knock sensor, O2 sensor, to adj "take out advance" the computer could remove/retard the time and adjust the carb settings...

Since the Poster has a 73 CJ with a 80s engine with a after market carb and distributor he will NOT be timed at 1600 rpms. He will time at idle with the vac advance hose disconnected from the distributor and plug the rubber vac line with a golf tee or similar.

AMC engines like 33 to 35 deg of total advance. HEI distributors are known for having more than this. The guys that say 12 deg of initial advance are putting in 1/3 or more of the advance in initial advance or a base line of advance... The initial advance never comes out its a base.... the mech advance and vac advance is what makes the engine work well and work with the load and operation of the vehicle...

With a proper functional distributor, initial advance of 4-8 deg is a very good range. I do not knock at 8deg but use 6 deg initial. Lower your initial advance and your CJ will start better too.

The distributor advance chart....
Is in the 78 and 79 FSM, Field Service Manual.... Once the computer is removed both the 70s and 80s jeeps can and should use this Advance Curve to set up your AMC engines. There are manual, autos, CJ and FSJ charts in the manuals.



ps
Jeepers that have a 80s jeep CJ and the computer is removed and/or have a aftermarket carbs need to modify the stock distributor so it works properly or change it out.... Most of the change is opening up the mech advance slots so the computer vitange distributor that comes with 5 or 8 deg slots can have/ use a normal amount of advance like 15 degrees the engine can acutaly use... this is what will give you hwy and higher rpm performance & efficiency... Easy to do just go slow with file or small grinder so you do not make the slot toooooooo big and go slow.... Use balancer tape to verify your work.... This limitation is one of the main reasons the hei seems to be a good change.... Learn to correct your old duraspark distributor and you will like that one tooo....


Thanks to MN CJ7 for this great info!!!!!!!!!!!!!!

Read more: http://www.jeep-cj.com/forums/f2/carb-distributor-help-10228/index2.html#ixzz1WZ4rYBn7

 

[1986cj7]

1982 to 1982 Jeep FSM is the best source and covers it fully

the 1600 rpms is true for Computer Controlled engines AND Carter Carbs and Full Sensors.... 1982 to 1986 Jeeps (1981 for calf)


If any of the pieces, computer, carb, O2, knock sensor are not working properly... the engine will be in limp mode and not work properly. I also guess few of us have all these pcs working as they did 30 yrs ago..

Thanks for all the great info again. Yes I don't have the smog junk or computer on Jeeppyy any more. Now I've set it to the 12 at 1600 and it seems to run better then at any other setting. I've tried 8-10 at idle but here at 6 at idle seems to run the best. Do you have any pics of the process of filing you sujested in the other post. Or if since its running well now, do I even need to mess with it. I do plan on pulling a popup camper some time in the future and would like to get it running as good as possible. Also where is the best place to get the fsm for 1986cj7 looked at several sites and don't have. Thanks again!!!!

 

[1986cj7]

Well since tring differant timing settings I've settled on 8 at 700 rpm. I've also had to start over on carb setting. And at 3 1/4 turns on the idle mix screaws it has alot more pep and power. Thanks for the info mn CJ7 . Since the beging of this post I've got my hands on a copy of the fsm, and yes it is clearly more detailed and better then the chiltion. Thanks again.