79 cj5 several questions

I just bought my 1st jeep w/ carter bbd on i6 258. my 1st problem occured when starting on a cold morn and the carb started pouring fuel out of the vent on to the header. I put a kit in it and everything worked fineafter reinstalling it until i went back to the guy who sold it to me to have him help adjust the carb. well i think it was adjusted better before he touched it but who am i to say, any way i readjusted it to where it wasnt as rich but after driving and acold night or two it wont start. what do i do now? also it has a three speed transmission that slips out of second gear when not under a load what could be the problem there and how much trouble is that going to be to fix? ill leave it at that and see what i get before bombarding you with too much

 

Popping out of gear is usually the syncro going bad. I had to replace the syncro's for third gear twice before I put in a T-18.

Jay

 

There's not that much to adjust on a factory carburetor, really. The best place to start is the factory service manual (FSM) or else the adjustment instructions that come with your rebuild kit. The kit instructions are usually pretty thorough. Mainly you adjust the float level, idle mixture, choke, fast idle, and curb idle, and that's about it.

Fuel coming out of the bowl vent indicates a stuck float. If you rebuilt the carb, you cleaned the fuel bowl and replaced the needle and seat, and you should have adjusted the float level. Not sure about the details of the BBD, but you need to make sure the float level is right and that you didn't bend anything out of shape when you adjusted the level.

Yes, popping out of second typically means that the bushing in the middle of second gear is worn. The gear will skew on the shaft, and push the shift collar off of the end of the gear.

You should have a T-150 transmission http://www.novak-adapt.com/knowledge/t150.htm - Novak says this is a Borg-Warner transmission, but it's actually a Ford passenger car transmission made on license by Tremac.

 

oooo kay thanks guys i'll do some checking and see what comes about on the tran. I did run into a carb guy today and got him to adjust the idle mixture and explain the workings for me so i can handle it next time. i think that will be sooon. when I tried to kill it it sputtered awhile and didnt want to die so thats next any suggestions let me now. any thanks again.

 

thanks for the ite should help tons

 

A few tings can cause "dieseling" or run on. Since you have been messing with the carb...I am going to guess that your idle is set too high.

 

alright magillacuddy I tried idling down but still get run on if the engine is pretty warm. could i have some timing prob or should i try the carb some more?

 

Okay...Here is the deal...
Run on happens because the engine with the ignition key off and foot off the throttle...still has enough fuel given to it for it to keep running.
Most of the time what lights the fuel when the ignition is off is a build up of carbon inside your combustion chamber. When the engine is run and gets up to operating temp...the carb gets hot enough to be an ignition source and will light the fuel.

So you have two problems...One is an out of tune carb and the other is carbon build up (probably caused by the out of tune carb). See...your carb is not running right...so the idle screw that holds the throttle plates open has to be turned in too far just to keep it running. When the throttle plates are open to far at idle...it opens up another fuel circuit that should only be open at part throttle and light cruise...So your engine is getting fuel at idle that it should only be getting when driving.
The reason that you have to turn the idle screw in so far is the hard part for me to diagnose without being there. It could be that your timing is so retarded that it wont run right without the idle screw turned in too far. The air/fuel mixture screws may be so far off that it won't run without the idle screw turned in to far...the passages from the idle air/fuel may be clogged.

So lets start with the carb. You said this is a Carter BBD...these or notorious for having idle problems...What happens is the idle tubes get clogged...this will cause raw fuel to come out of the venteris...Thus making it run really bad and the reason it has run on. To check if you have this problem...take of the air cleaner and look down in the carb when idling. If you see fuel coming out of those little nozzles...then you have this problem.
If you do not see this happening...open the throttle a little bit by hand...those tubes should spray fuel...if they drool out fuel...then you have a problem.
The clogged idle was such a problem that Jeep actually recommended drilling them out bigger to avoid the constant clogging (0.032 I think)...but you will want to confirm that...because I don't recall if that's correct.
If this is not the problem...you may have a vacuum leak...you can check all the hoses and the base gasket....Try these things...and if none of them float...we can move on to other things.

About your carbon build up...you can take care of a majority of this quite easy...Start the engine...Take the air cleaner off...pull the engine RPM up a little and slowly pour water right into the mouth of your carb...It will want to die...give it more throttle...This works pretty good (believe it or not). Do this a few times...don't be afraid of the water...but don't go nuts and shove a garden hose down it...You can put in as much as you want...but try and keep the engine from dying while doing it. This will take out lots of that excess carb build up.

 

That water trick has been around a looong time. I member my ol gran pappy doin that to a 52 Dodge truck back in the day.. He used a Coke bottle, and dribbled it in..

 

Yep...used to do it as a young man when I worked in my Grandfathers auto shop. Many people back then would buy a performance car...and then just idle it around town for months on end...It would start to get carbon built up...I would do the water trick and then take it out and flog it...(the last part was more for my own enjoyment).

 

okay I took the thing out lastnight and drove around for about an hour and when I got home and shut it off it died exactly as it should, but a cold front had moved in 33 degrees rain sleet and what have you whereas in the past it had been fairly warm. if that has any bearing or not I don't know. anyway a little about the carb. It has been stripped down to near nothing. 2 or 3 vac hoses and a manual choke. Ive got the idle screw turned out till it no longer rests on the thingamajig but the jeep starts easily and stays running after only a minute or two of tlc, but I have noticed it has a lag upon acceleration. the thing used to have quite alot of backfire or what have you on deceleration especially in the lower gears. I know some is to be expected but I thought it was excessive, anyway that is now at amore acceptable level. I have checked the fuel in the carb and that is operating normally I think, but I will keep in mind drilling it if need be especially since I dont remember if I had a spray or a dribble (i'll check that out soon probably when I try to drown the thing). as for vac leaks I just capped off all tubes except the one that goes to the valve cover. that one gives me some caution. It hooks to a T shaped thing that is stuck through a rubber grommet in the valve cover. I just plugged the other side of the T which I'm guessing is the pvc. on that same note on the other end of the VC there is a little fiber filter sticking out of it it is pretty dirty is this some jerry rigging or standard fair?
as far as the air/fuel goes should they be turned in about the same distance or will they be different? is there a semistandard to begin adjustment? or is it just experience and luck that gets you to a succesful adjustment? i hope it isn't the latter cause I have neither. I should probably take it to a mechanic but that just doesn't seem to be something that I want to do. i am determined to see this thing through.
Any way thanks for the advice I'll get those things done then check back.

 

Make sure your fast-idle cam is pulled off completely when the choke flap is completely open. You have a manual choke, but that should still provide a fast idle.

The best reference for these Jeeps is the factory service manual (FSM or TSM) availalbe here and several other places too http://thejeep.com/shop/TECH+MANUAL....html?osCsid=6f39cc6f45958e0cc5738fb1f0e0e00c If you want to work on the Jeep yourself, you should have this book and read it.

The idle mixture screws should be set the same. Note they only control the idle circuit mixture, so above about 1000 rpm they do nothing. They should be set to best lean idle. Turn them all the way in just tight, and then both out, say, 2.5 turns. Then adjust the curb idle screw to the proper rpm. If the carb won't idle down like this, then there's something wrong with the idle crcuit. As McGC wrote, the BBD often has idle problems. Terry Howe's article covers the usual problems: http://www.jeeptech.com/engine/carter.html

 

Also, you should have an EGR valve. A dirty EGR valve pintle will make it stick open and cause a ragged idle. Take the EGR valve off, clean the pintle thoroughly with a wire brush, and put the valve back with a new gasket.

 

what and where is an egr valve

 

RTFM, my friend.

http://www.toeksplace.com/jeep/amc/4A_EmissionControls.pdf

This is for '75, but the gist of it is the same.

 

Tim pretty much covered most of it...Just wanted to add...a backfire on deceleration or if you want to get picky "afterfire" is caused by a rich mixture, (unburned fuel lighting off in the exhaust)...An exhaust leak can also cause this...because of the extra air added.
I am almost certain your running very rich.

 

well you are right ive got an exhaust leak in header .