Carter carb

Hi Guys !
I'm new at this and at asking for help but here goes. Last year I bought a 73 cj5 and like those who have gone before me I am going broke! new body suspension you name it. The saving grace is the 258 which seems to be in fine shape no smoke no leaks! alas going over Monarch pass last week it dogged out in third and I got a headache from the gas fumes. Other than switching to a 4 speed trany what can I do to aleve the lack of third gear power and fule dumping 1 barrel carter? HELP!!!:?

 

I have been over that pass, You have some elevation to deal with there. I dont think there is anything wrong with your Carter YF that cant be cured, It may not even be the original specification carb let alone calibrated for high altitude ( go to the home page and read Jayhawkclints entire article on Altitude Density )

If you are going to frequent high altitude you may have to recalibrate the carb, Especially if its a rebuilt unit and possibly not exactly application correct.

Some simple things first, Is timing correctly set with the vacuum advance line off and plugged, Is the air filter element clean, Is the air cleaner the stock unit or something else, Choke sticking or not open all the way, If you have a cold air intake hose from the air filter housing to the front of the grill make sure its not partially plugged ( mouse or bird nest ).

How does it run at lower altitudes, What gear ratios do you have and what size tires are you running.

 

Hello Brian
This is Colorado it's all altitude Timing is good climbing in first two gears is fine This machine is as far as I can tell all stock I just rebuilt the T14 tranny and the axles had 35 years of unchanged Fluid/ water when I got her. She just loses ground in high gear/3rd Thanks Tom

 

Where did this rig come from originally, Does it run rich all the time or just when pushing it at higher than usual altitude, what is the elevation where you live and refresh my memory please.........how high is Monarch Pass, I cant remember exactly.

 

Monarch is about 12,000 ft I'm at 5,000 she loses ground on steep hills at this alt also just never as bad as monarch I was waiting for spandex clad pedal pushers to pass me as I kept switching gears and runing her close to red line

 

If all the easy items I mentioned are ok and tire size is still stock it should pull pretty good at 5000 feet, If I remember correctly vehicles sold during that time frame for sustained use at or over 5000 feet were calibrated for high altitude use.

Have you shut it off and done a spark plug reading after a good pull in high gear to see if its running rich, That would be useful information. Do you know if your float level is correct.

Will catch up with you tomorrow after work. There may not be much of a power increase attainable at 10000 to 12000 feet with recalibration but we can do something about running rich in general from 5000 to say about 8000 with minor changes to the carb.

 

Well. To me, this sounds like a gearing problem. What is your axle ratio? The T-14 transmission has a big gap between 2nd and 3rd. This problem can be particularly evident if you have the standard 3.73 axle ratio. The gear ratios of the T-14 are 3.1, 2.61, and 1.0 ... you can see the problem. IMO, the T-14 is a PITB in this regard. The T-15 ratios are 3.0, 1.83 and 1.0 - giving you a much more useable 2nd gear downshift in cases like this. A T-15 from a V8 CJ would be a cheap and easy swap... you might have to change the driveshaft lengths, but maybe not. Really easy.

Realize that, at altitude, the power of the engine will be down regardless of what you do. When you lean out the mixture like you're supposed to, the mixture is right but you simply have less fuel to burn. Fighter planes used to use superchargers, just for this reason.

You're on the right track with Brian P.'s advice regarding the mixture. I'd suggest you straighten that out and see if things improve. You're always going to have the problem with the useless downshift with the T-14 though, IMO.

<edit> The real cure for drastic changes in altitude is Fuel Injection. Lots of Jeepers are running GM TBI from a 4.3L Chevy. You either need to use an aftermarket ECU (Megasquirt) or hack the ROM in the GM ECU to really optimize one of these systems, but it's quite do-able. Howell sells a turnkey system that's well regarded. Another option is a Motorcraft 2150 carb from a later Wagoneer - many of these have an altitude compensator that works well.

<2nd edit> The T-150 is also a good and inexpensive replacement for the T-14 behind a 232 or 258. Not as strong as the T-15, but a similar easy bolt-up, likely more available, and stronger than the T-14. Ratios are 2.99, 1.70, 1.0. Parts are easier to find than for a T-15 too.

 

:iagree: Thanks timgr, I was hoping someone with more experience on the gearing would chime in

 

Another thing to check is if your CJ has a TCS (transmission controlled spark) system. This is an emissions device that removes vacuum advance from the distributor in top gear. There is a switch on the transmission that controls it (in addition to the backup light switch). If you have it, there's a solenoid on top of the engine that controls the vacuum. Not sure if it's normally open or normally closed - but you can figure it out. Make sure you have ported vacuum to the distributor at all times - pretty sure that extra advance will help you at altitude, and removing the vacuum advance in third isn't going to help.

 

Well ok

I'll start with the float and see if I can find a jet to put her more in a mid range between 5,000 and 12,000 maybe say the 9,000 mark or find that later carb with the compensater on it. before looking into the gears.
Thanks to all and wish me luck I shall return!!!!

 

Being from the great state of Colorado myself, and spending a lot of time lugging manual trannied, carbureted vehicles over the high passes, my opinion is that you just learn to deal with the shortfalls. Make sure your carb is in good shape and that your tune up is correct, shift down a gear, and enjoy the ride. I've been over many passes in second gear of my granny low T-18 at 10 to 15 mph. If that's all you got, that's all you can use.

Don't attempt to tune the carb to run at all altitudes. Tune it to run at the altitude you spend the most time at, then lean it out slightly if you spend a lot of time above 8000 feet. If you're like most of us, the time you spend at 12,000 feet is miniscule, it's not worth trying to play with the carb every time you change a couple thousand feet in altitude.

 

ya know I hunted in our back yard last year. The drive up the Poudre had me installing a sway bar soon as I got back here to Canon City. No Elk or deer just moose and a wonderful ride over the Devide Thanks Tom

 

You have to realize the stock 258 has a net horsepower of 110.
Going up in altitude really kills the power.
If you are in a hurry going up the pass, try a 360 with a Motorcraft 4350 or equal. This will do the job.