Scotts cj7
New member
What should the timing be set at on my 1985 258 six ?
setting the timing
- Thread starter Scotts cj7
- Start date
greg92jeepxj
Official Supporter
The chilton manual for this model year has it at 9 degrees BTDC and 600 rpm idle speed for auto trans.
greg92jeepxj
Official Supporter
Forgot to mention that the vacuum line should be removed from vacuum advance and plugged . Also , any electric motors that may be on the carburetor , I.e , a/c idle boost , anti-diesel solenoid , idle speed control , etc. must be disconnected temporarily until timing is set. I could not properly identify which ignition system your engine has so I do not know which distributor it has but if there is a computer feedback wiring harness for advance/retard control , it will have to be temporarily disconnected as well . It is always best to disconnect any electrical with ignition off and reconnected ignition off as well. The purpose of disconnecting vacuum and electrical is so that base timing can be set without engine vacuum cannot disturb idle and throw off setting and computer feedback wiring disconnected so the ECM cannot correct settings your trying to set. One more item ; disconnect and plug EGR vacuum and emissions control such as evaporative emissions canister vacuum .
greg92jeepxj
Official Supporter
If you have the dura spark or duraspark 2 ignition system , I don't recall being able to disconnect this wiring since the coil and solenoid are wired through it and will prevent the engine from starting and running. If needed , will research the tune up procedure for this ignition system .
Scotts cj7
New member
It should be simple now that I have the new Holley carb.
greg92jeepxj
Official Supporter
Agreed . Guess I got carried away with the carburetor solenoids . That wouldn't apply to your new set up. A good set up to monitor rpm and performance while adjusting timing would be a tachometer and a vacuum gauge. You can set a baseline timing and road test it and try a little advance , probably no more than two degrees and observe engine vacuum for improvement. This of course will need road test each adjustment. I know I may be getting carried away again but just thinking of your Holley carburetor has me turning you into a quarter mile tuner !
Scotts cj7
New member
Sorry I haven't be out there for a while. I still have not set timing I will soon. I also have to replace front engine pipe I cant understand why there is no donut or any gasket of any kind between the exhaust manifold and the engine pipe. The glass pack also has to go it just doesn't sound right on a six with single exhaust. There's always something to do on this Jeep.
greg92jeepxj
Official Supporter
Looking forward to the results of the initial timing setting and vacuum the engine pulls after timing set. Not sure how the down pipe fits your jeeps exhaust but wondering if it's like this ford 3.8 windstar engine I just did head gaskets on . The exhaust manifolds and Y pipe fit together tight . The manifold has a rounded end where the down pipe mates to it and the flange holds it up via two studs and nuts to make a tight fit . Maybe your jeeps exhaust is similar ? Funny though , my '92 jeep header has a donut gasket that the header pipe mates to with two studs . I do see your point. Yeah , there's always something to do on a jeep ! But we like it like that !
Scotts cj7
New member
The pipe mates up to the manifold. I think what happens as the pipe gets old it gets thinner and starts to leak. Either way its time for some new exhaust parts its getting loud. I also have to adjust my shifter kick down linkage I want it to drop down into second gear sooner when I start up a long incline. Getting busy with customer work so I cant play with it right now.
greg92jeepxj
Official Supporter
None of my CJ references were helpful to find any mention of a gasket/donut so I checked rockauto . There is a donut listed which I could not clearly see from its photo if it is made to sit between belled casting of the exhaust manifold and belled flange of the engine down pipe . The only reason I. Emotionless the V6 ford 3.8 engine is because it has a similar belled cast on the exhaust manifolds and similar belled flange on its Y pipe. There are no donut gaskets on this engine. Interesting. Rockauto lists a donut but for the 258 CID but wondering if one was used. Usually a donut seal slips onto a round cylindrical surface of the exhaust manifold to mate with a belled flange of a pipe. But following the example of the previously mentioned engine that didn't use one , wondering was it meant to or not. If so , it would most likely be small and not very thick ? Hoping your parts supplier has a good listing for your jeep model year.
as far as the kick down linkage adjustment , follow the book on this and take the jeep out for a drive to see if it meets your liking . You want to be careful that it's adjusted right or the trans experiences possible over heating . I don't recall there being a way to tailor to your need but was always stressed that kick down and band adjustments needed to be correct and by the book . I understand the need and can see how the previous owner may have been abusive in this manner.
as far as the kick down linkage adjustment , follow the book on this and take the jeep out for a drive to see if it meets your liking . You want to be careful that it's adjusted right or the trans experiences possible over heating . I don't recall there being a way to tailor to your need but was always stressed that kick down and band adjustments needed to be correct and by the book . I understand the need and can see how the previous owner may have been abusive in this manner.
Last edited:
Scotts cj7
New member
I have a pretty good idea of what the kid did with this cj I was once young with a 4 buy in the woods. The trany I will make small adjustments at a time. Im going to put on a new front pipe and see how it sounds and take it from there. As of right now I don't have much time to work on it. But ill get to it. Thanks for the searching.
