Hesitation Just off Idle

I think with the cup turned like it was it isn't shooting gas at the beginning for the stroke because the OD was slightly smaller and the bore on the pump area looks te be tapered. If someone has used the leather version can you post what the pump rod assembly looks like? I amy run to the j yard and get a junk 2g for the differnet style.

 

A short time ago we had a lengthy discussion on 2g accel pump assy. I believe we finally came to the conclusion that the pump assy that originally came with a check ball built into the pump assy used the leather cup. New engineering and design of the pump negated the old units use for the check ball built in to the pump rod assy. Assuming some rebuild kits provide the leather cup for those carbs that still have the old rod. The rubber cup will turn upside down if you don't lube it on assy, for example installing it into a dry carb. Light oil or vasaline on cup before assy should keep the cup in the right direction upon assy. I see no reason for not using the leather cup if it fits properly if that is your desire. Letting the rubber and leather cups get dry is the killer.

 

Walt, is it too late for the cup I have do you think. I probably only have about 50 gallons through this carb. I think it has been like this since I rebuilt the carb 2 yrs ago. SHould I try to re-use it or get new? In all honesty I have lived with the stumble since I started driving this and I finally got tired of it and started tinkering with it this weekend. I am hoping this cup is not ruined. It doesn't look worn or scuffed in any way. With the fuel in the carb do you think it will seat properly?



Thanks

Todd

 

It's worth a try to roll it back down and put some lube on it and put together. If it seems plyable and shows no cracks it should work. I would do it. If no good then I think the accel pump can be purchased separately with-out the whole kit.

 

I had the same hesitation problem with my 225 v6 in my jeep years ago. I rebuilt the carburetor a couple of times and cant even count how many times I adjusted the timing. The problem.........the timing chain was so wore out it was stretching enough to cause the engine to hesitate off idle. Trouble is that the only way I know of to check the timing chain is to pull the timing cover to check it. That's my $.02 hope it helps

 

Thank you all for your support and caring ways! I love this site. Walt, I put it back together after taking the cup off and rolling back the right way. I then took it put it in the carb base with fuel and manually pushed in pulled it until i was out of fuel to see what it would do. It stayed, I put it back together and a few cranks it fired up, refilled and runs off idle like a champ(btw it was dark by the time I got it done, I am glad the 2g is so simple). Chalk this one up to a good learning experience for the next one. Thanks for the lube tip Walt.

FWIW the gaskets that come with these rebuild kits suck. When I was having float trouble in the past having to take the top off numerous time the kit gasket stuck to the castings and just failed after like 3 time of apart together etc. What I did to remedy this is took what was left of the old one, laid it on some new decent material and used clear packing tape and taped the old onto my new blank. I then with an exacto knife carefully cut out the new one using the old as a pattern. Once it was completely cut the new one has no tape on it and has worked very well. Also, the old on with the packing tape can now serve as a pattern for the next one if needed. Just thought I would share this little trick.

Todd

 

Glad you got it working..

 

One thing to help your gaskets from sticking and ripping from taking the carb apart, is to smear some light grease on it.. just a very thin coat - rub it on with your finger.

 

I got excited too soon. Still hesitates a little but not as bad. Runs better but I still need to work on it. I think this might be something else.

Couple Q's for tuning:
1. When I set Static timing with the vac adv. plugged and then put the hose back on should I see a difference in the timing? Mine doesn't change.
2. When I set the timing at 5 I only have about 16 in of vac. If I adjust the air/fuel it doesn't change. Thoughts? It runs louder and rougher at 5 then if I advance it to about what I think is 20.
3. Could the float being too low cause any of this?
4. Are ther 24 teeth on the timing gear? If I am one off could this account for the best idle at about 20?(360/(20-5)=24)
5. Could plugged jets do this? It runs good under load. I did a little hill climbing with it and it does good under this load.
6. I am wondering if I have abnormally worn the cup on the accel. pump and now I am not getting 100% fuel push at the beginning of the stroke.

I have finally buckled down to tune this and I am a little frustrated.

Todd

 

One tooth off on the crank would account for 18*. 40 teeth cam and 20 on crank.

 

I might not be far from that 18 deg. I am just guessing. I know I lined the marks up properly which is confusing me. If I am off I guess I can just run it or maybe try to fab a custom degree marker.

This whole tuning is a littl eout of my expertise.

 

Like 600' above sea level.

 

Hey Todd,

I had the hesitation off idle thing for awhile after I rebuilt the carb a couple years ago. I really thought it had to be a vacuum leak but I couldn't find one. Eventually the problem went away on it's own so I was never able to figure out what it was. HEI distributer.

A few years before the above incident (when I first got the rig) it had the same problem and it eventually went away on it's own. Original points style distributer.

Because the problem started the second time right after a carb rebuild, I think the problem is either carb or vacuum leak (not timing).

Just throwing out some info in the hopes that it helps. Good Luck.

 

I ressurected this thread after reading some of the latest HEI and carb/dist posts.

I replaced my accel. pump set-up with a junk yard leather version that looked new. It worked! I had good stream and the thing ran good. I played with my off timing, got it purring pretty good by ear and it drove good around the property.

Buuuuuuuuut, a little light went on reading cj5/442's woes and it finally dawned on me that i never paid attention to the plug wire locations on the dist cap. Sooooo, since i knew I would never be able to tune this properly I spent an hour and a half messing around with it today as follows:

1. Pulled dist, cap and removed wires from cap(at this point i wished I had diagrammed their location)
2. Pulled #1 plug and rotated engine to TDC
3. Re-installed dist in decent location( took me three tries to get enough adjustment)
4. Re-installed th cap(by the third time I had nocticed the little mark on the dist housing for #1 location to line up the rotor)
5. Re-installed the wires in their appropriate location
6. Started it up and set the timing to 5 and same problem.

I now notice that the accel pump is doing its thing and the hesitation isn't off idle it seems to be the timing is off and it just about dies and sputters if you leave the gas pushed in. I am now leaning toward this problem as all timing but I am even more baffled now that I re-did everything and it is worse I think. Before I could advance the timing enough to make it run decent but not now.

Stumped. Help. Please.

 

Sparky, I noticed your answer to my question in cj5/442's post. So if I still had points plug wire placement wouldn't matter? Drop the cap on start the order at wherever the rortor is pointing? I have a pertronix. Does this change things. Do I need to do what I did today?

 

Hey, that sucks you are still having trouble. I was reading though the posts here.. and Do you have a HEI ? Or just a petronix ?

To see if your timing chain is loose.. you could possibly check it though the fuel pump hole in the timing cover.

Right now.. for you I would try making sure there are no vacuum leaks. Using a bottle of starting fluid or carb cleaner, and make sure there are no leaks around the base of the carb, where the intake meets the head, throttle shaft - sometime they get so worn it creates a vacuum leak.

 

I did not read the whole thread ,,,,, but when you hit the throttle ,gas is jetting out the venturi cluster?, have you tried to bend the acc rod (that goes from pump to linkageto sort of time the shot.to check the timing just line it up on the marks and rock the motor with a breaker bar from tight to tight amd have someone up to check what you have , spray everything (except the headers) and look for a change in idle sound .again I did not read the whole thread ,,,,,,,,,,,,,,,,,,,,got to go.................

 

My timing set is new so i don't think it is loose. I moved it last night(having a party tonight and needed room on the driveway) and it was a battle to feather the gas just right to keep it running. CJ5/442 I do have a good double stream with the different accel pump I put in and it ran pretty good last weeekend when I was playing with it. I am frustrated to say the least. When I got it all together last year I drove it with my th350 set-up and it ran ok. I knew it wasn't right so this is what prompted this thread earlier this year. Life and work got busy this summer so I didn't have time for it. I just got laid off so I started tinkering again. Maybe too much!

Did my list of my timing attempt look right? Do I need to have the plugs on the correct terminals on the cap? I do have a pertronix with the stock cap and rotor.