[Mr.Crowley]

no problem..There are a few on here that helped me out with the webers when I fist started messing with them,and Im just passing the torch..Good luck./.

[JeepHammer]

I'm glad there is a Webber guy here!

I had the factory school on Holley, and that bleeds over into a lot of carbs, but I don't do well with Webber at all.
And I grew up all through the Q-jet and Carter AFB carb fads, so I'm a pretty fair hand with them, but something about a carb that uses emulsion tubes instead of direct feed for idle mixture that I don't get!

Anyway, My question is, Why 1,600 RPM for idle when you are setting timing?
Wouldn't you be well into the centrifugal advance at 1,600 RPM?
Anything you set for advance would be negative (After Top Dead Center) after the centrifugal advance takes 12 or 15 degrees out of the total timing at idle?

I know why Jeep wanted you to do 1,600 RPM with the Carter BBD and timing computer (and it's fiddling with the fuel and timing), to get beyond the range of the computer so you could get a good reading, but it's this a '78 or '79 with no computer?

Just asking, I know there has to be a reasoning for it and I'm wondering what it is with an I-6?

[Mr.Crowley]

I dont really have a reason for it,but on the few jeeps including my own,''all without the computer controlled carbs'''' the seem to be spot on with timing..It has worked for me many times over,but of course every jeep is different..Mine likes about 3-4 initial timing..But if I recal the under hood sticker on my 80 cj tells ya to time this same way..I accounted it for the ecm on the inner fender controlling part of the timming but I may be wrong..I have know to be incorrect allot..mostly cuz I forget very easily..I have young heimers

but if all else fails with a 79 you could probably run the timing up to about 12 degrees Before top dead center without pinging..But always keep an ear out for pinging while under a load..

edit..Im just babling in this one..lolMy 80 does have it under the hood,but its an 85 grill..I forgot about that..lol

[JeepHammer]

Yup, part throttle cruise when everything is running off the primary jets, extra lean, and full vacuum and centrifugal advance.... You can get 'Ping' pretty easy.

Especially if you have tall gears and tall tires slowing everything down!

I normally do V-8's, so there are still some 'Mysteries' out there in the I-6 world I don't know yet.
All V-8's are pretty much the same, no matter what the rabid (insert make here) die hards insist...
Every engine brand has it's own quirks, but for the most part, you can treat them all about the same when it comes to tuning...

[CJ Chet]

You sure do need the fuel regulator, Weber says 3.5 PSI max. But be carefull what type you get. I'm on my third one. I threw away the first two and now I have a Holley - Definitely a keeper. Stay away from Mr. Gasket - it's CRAP! The Holley is the only one I found so far that actually works properly.
I'd also upgrade the distributor to get the full benefit of that Weber. I have an HEI which I really like, but there are also others that are very good.
I have a Performance Distributors DUI running at 12 degrees with a Weber 38 (no emissions or computer stuff), and it pulls like a Harley Davidson.

[Fjguercio]

Mr Crowley and Mr Hammer,

Ajusted the timming at 1600 rpm at 8deg advance and worked well, advance vaccum removed and pluged. Also went down to about -3. About 6-7deg advanced at 1600 rpm turned out to be the best. I have more power, smoother rpms and can easily go to 3000 rpm. The 1600 timming is about 7-8 deg more retarded than where I had it set when I set timming at idel.

Note: After adj time at 1600 rmp and return to idel at 800 rpm. When I removed vaccum advance I saw the RPM drop up by a 300 rpm or so. Is that normal. Vaccum at 800 idel is around 15", at 1600 rpm around 25". Both have very steady readings.

I also saw the time mark on balancer drop a good 1 to 1.5 " or 8-10 degrees a few times during my work for just a split second. More so at the beginning of setting time at 1600 rpm. Then started watching for it more and would not do. The time mark was very steady, as was the vaccum guage. But I did see the time mark drop 5-6 times during my work. Maybe it was ground. Could have also been my coil pick up on #1 spark plug. Just thought I mention it.

It idels very well and sounds like a new engine so getting close

The weber 34 is still not just right. I am loading up when the 2 barrel goes in. I have the 40 primary and 50 secondary. I think I am going to switch and try the 50 in primary. MAYBE Less likely to load up.

The idel A/F still does not work, or slow engine when I screw in, and I feel something may be wrong with the carb. I will play some more with this, may send back to Weber for them to look at. I just about took out the idel adj screw, holding the accelerator cable to keep it from stalling. If I let the throttle adj all the way down and it would stall. The idel adj screw holds the throttle up about 1/4" and still could be a or the problem. This is way more adjustment than than the 1-2 turns normal in Mr Crowley's note. I also have some slack in my cable so the throttle does bottom out. Mr. Crowley any more ideas with this.

I also found my tack was set wrong at 8 cylinders vs the 6 so I was reading lower rpms. My neighbors time light, I used this time, has a tac and it did not match. I have a neighbor that likes to play GREMLEN and I showed him the tac before I installed it. Shame, I was using the info and was missled by it. Operation now matches where I thought it should be, Hwy speed 60mph not at 2200rpm. Same neighbor also moved the power steering stud that screw into the aluminnum intake. I put permanent locktite to hold in place when hand fitting power steering brackets to clear Borla header. Gremlen / neighbor was with me during assembly and said it needed to be moved after I was fumbling with it for a moment. ANYWAY, I have gremlins in the garage, time to hunt!

I will post how the 50 primary and 40 secondary works out.

Getting very close,
THANKS FOR THE HELP!!!

[Fjguercio]

VERY GOOD NEWS!!!

I have the Weber 34 working well with the 40 primary and 47.5secondary. My spark plugs are now a nice tan color and most of black is gone. I have 700 miles on the rebuilt 258 and three oil changes. Jeep started today at 5 deg F after sitting for week and poped right over then idled well when i popped of the choke. Could not ask for more. Engine will easly go to 3000 with out pushing too hard on new engine. Today took 70 mile HWY trip and got 15.12 mpg with two stops, one 15 minutes, the second two hours. NOT BAD. I am hoping to get up to 23mpg with warm weather and longer trip.

I found the codes for my axles and have 3.54 gears AMC 20 Dana 30 with the t18b wide ratio, granny gear 1st, and 33" x 12.5 tires. At 55 mph reading I am just above 65 mph say 68. GUYS WITH BIG TIRES DO NOT FORGET TO INCREASE YOUR ODOMETER MILEAGE WHEN CALCULATING MILES PER GALLON, MPG. The ratio of 68/55 x odometer miles gives the actual miles traveled. BIG TIRES mean we put less miles on the odometer. Have a friend travel next to you on the HWY with a stock car tires, compare mph using cell or radio and you will be close. FYI

I STILL DO NOT HAVE THE WEBER IDEL SCREW ADJUSTED RIGHT YET. JUST BEEN TOO COLD TO WORK ON IT. I CALLED WEBER TECHNICAL, THEY WANT THE IDEL TURNED DOWN TO 600 SO THE PRIMARY IS NOT BEING USED. THAT IS THE ONLY WAY TO GET THE IDLE AIR FUEL SCREW ADJUSTED. I discussed with him my Chilton book wants my idle at 850 for the 1978 258 and WEBER said that is too high and not necessary with the WEBER 34. JEEP & Chilton wanted that idle so high because of the Carter Carb they were using. WHY IS THE 1977 & 1978 YEAR OF MFG 258 LIST AN IDLE OF 850 RPM AND THE OTHER YEARS IN THE 70'S LIST 600-700 RPM?? THESE TWO YEARS LIST A MUCH HIGHER IDLE RPM????

What do you other JEEPFORUM guys think??? The rebuilt engine idles well even down to 600. I am thinking of trying to use 650 for the idle setting. I also used a vaccum guage last time playing with idle levels. Below 850 the vacuum levels realy drop off fast. I remember at 850 the vac level was 19-20 range and when droped to 650 the vac level was closer to 12-13.

This could also be part of the reason the 1600rpm tune up worked so well.

The Engine runs well, Next I will be upgrading the CAP, ROTAR, PLUG WIRES, and used FORD E coil. I will also report what that does to my mileage and rpm range with out changing anything else. The new Ford Style CAP/Rotal looks to keep the same rotational positions. Will be interesting test.

After I get the mileage I will adjust the WEBER carb & timing again and see what the rebuilt 258 likes with the hotter better spark with the FORD E coil upgrade also known as the TFI.

Thanks
FRED

[MuddyMules]

Please continue adding to this thread. I NEED this info as well. I have the 34DGEC and it wants to sputter on me and run a little rich. Keep up the great posts! I am following this thread like a shadow. Thanks.

[Mr.Crowley]

I noticed if the idle is just above 700-800 it will pull vacume in on the vac ume advance to the distributor..And will cause the idle to jump up a few hundred...

The difference in the idle rpm's for the different years is most likely emissions equipment and ignition specs..

[JeepHammer]

Timing jumping aorund a little is usually a sign of a loose timing chain if there is a lot of wear, and it can also be a sign of cross fire or multi-fire in the small caps with short rotors...

--------------------------------

Nothing else I can help you with Padawan Learner, it's time to use the 'Jeep Force' for yourself!

You chased the bugs out of it by sticking to a system, and learning how things worked with each other, and that eduction is invaluable...

I spent years figuring out what does, and does NOT work with ignition and fuel systems... So I can give you a big leg up on that,
And I had a friend here earlier that used to race Webber/Ingleese carbs, and he said Mr. Crowley was pretty much spot on about the carb instructions.

Glad to hear you are running and satisfied!

Now, remember to make ONE change at a time, so you can determine what effect that ONE CHANGE had on all the surrounding systems!

[Fjguercio]

Originally Posted by Mr.Crowley

I noticed if the idle is just above 700-800 it will pull vacume in on the vac ume advance to the distributor..And will cause the idle to jump up a few hundred...

The difference in the idle rpm's for the different years is most likely emissions equipment and ignition specs..

I have nothing installed vaccum, emissions, or pollution except the PCV valve. Power Brakes installed but doesn't count. Does that mean if the engine runs smooth at 650 no reason not to use it??? Or am I better off keeping a higher vaccum level at idle for some reason??

I capped the EGR with a aluminum plate and gasket. I also do not have the charcoal cannister installed. I have it, cleaned it but not in. I have also read a few threads that say it is necessary??

As for the ignition the 1978 and 1979 use the same Duraspark control modual and Dissy. IN THE CHILTON BOOK, the 1979 drops to 700 rpm at idle. ALSO I do not think 1977 is the same ignition at 1978. I AGREE WITH YOUR COMMENTS AND EXPLINATION BUT STILL GOOD MYSTRY.

[Fjguercio]

Originally Posted by JeepHammer

Timing jumping aorund a little is usually a sign of a loose timing chain if there is a lot of wear, and it can also be a sign of cross fire or multi-fire in the small caps with short rotors...!

The 258 engine is fresh with rebuild. Timing Chain and such brand new. I do have that little cap, purchased new, and it has the aluminum contacts you guys said stay away from. INTERESTING. This could also be why my higher rpms are limited a bit also.


Thanks JeepHammer and Mr Crowley,

My force is getting stronger.

[Fjguercio]

MORE GOOD NEWS!!
This weekend replaced the NEW stock style Cap, Rotar, Plug Wires and replaced with the USED Ford E Coil up grade with the NEW Larger Cap w/Brass Terminals & Adapter Base, Rotar, new style Plug Wires Napa Beldin Premium Lifetime. Just with changing the PARTS & Coil my hwy mileage went from 15.2 (last wk) to 17.5 MPG (this wk end). This is an improvement of 2.3 MPG. I DID NOT TOUCH THE TIMMING OR CARB. This was at single digit temps and a 1 hour stop during the trip, so complete cool down.

This is rebuilt engine and is still not broken in. I hope / target 23 mpg HWY during the warm summer months

I have a slight roll, but many would consider perfect, and does not start as well as it was. I added the DuraSpark ground yesterday. I will adj the timming and carb next warm spell. Will report more shortly.

For those that have interest have nice way to mount the Ford E Coil in the stock location with pictures on another thread.

http://www.jeepforum.com/forum/f8/tfi-ford-e-coil-installation-location-bracket-513978/

[Fjguercio]

Great News!!!!!!!!!!!

The 1978 Jeep Cj7 Is Running Just Like Brand New. Even Goes Down The Road True And Steady. I Am Not Done Yet, But So Close.

i Just Completed The The Duraspark Ignition Ground Wire Addition And Adjusted The Timming & Carb Settings. Very Nice Outcome. I Have The Idle Down To 650-600, The Slight Roll Is Mostly Gone, And Is Starting Like It Was Before I Added The Ignition Upgrades. With The Ignition Upgrades I Was Able To Advance The Timming 8 Degreees From Where I Had It Set Prior. the Engine Acts Like It Has An Extra Piston And I Gained 1000 Rpms In The Operation Range. I Did Not Push This Newly Rebuilt Engine With 800 Miles On It, But Felt It Would Easly Go Over 4000. I Went To The Upper Range Of 3000.

Very Very Nice. Acts Like A New Jeep

[Mr.Crowley]

great news..A properly tuned weber is a great addition to a jeep..Its just that the un-american way of adjusting them is a little strange to some..The best way to describe them is an overgrown motorcycle carb..In wich were I learned the jist of how they work racing atv's for quite a few years