Stumped!!!

[Red76]

Ok everyone, I just cannot figure this out. First of all thanks to everyone for the help in my prior post. But alas, I'm back again.
I think my issue in in the ignition system but maybe I'm wrong. It started on a long road trip. Running rough, missing, ect. I found that the major part of my issue was that the running set of points were not opening. I also noticed that the tach was bouncing up and down. Just acting crazy.
Fast forward....
I have replaced:
Both Sets of Points
Both Condensers
Rotor Button
Distributor Cap
Coil (Upgraded to a nice Bosch)
Spark Plugs
New plug wires are on the way

Here is where I stand. I can start the car and while its cold I have a pretty smooth idle and good power. When it starts to warm up that’s when the trouble begins. The idle gets very rough and becomes weak enough to simply shut off the motor and it is no longer smooth at a higher RPM. Dont think its the timing, I set it "by ear" in one degree increments and got it as close as possible.
I have tride both the single and double point set up with the same results. Points and Plugs are all gaped right. I'm getting very good spark. Before I left on the road trip the carb was rebuilt (I guess about 700 miles ago) but I had no issues the first half of the trip so I don’t think that’s an issue. Another issue that might give a clue is the tach is dead now, no movement at all.
Might this be an issue with the choke and would it be helpful if I posted a youtube vid of how its running?
Again, thank you for all the help

[majicwrench]

SOunds like choke is working properly. Engine runs well cold. When warm, choke is probably open, like it should be. If that is when problem starts (warm), is possibly/likely low speed circuit in carb restricted. These plug often and easily, and result in poor or no idle, stumble on accel, and poor cruising. Put your hand over carb at warm idle to restrict the air flow into carb and see if idle improves.
Keith

[Red76]

Keith, I had tried that and I did see an improvement. Now to figure out where that part is you mentioned. Is there another name it goes by. I dont see it listed in any of my carb diagrams.

[Estaban]

how old is your timing belt? If it jumped just a little bit it could throw things off yet still run.

I would hazard to guess it's not your ignition (points plugs, cap, rotor, etc...) since it runs cold and you have replaced the coil.

[Red76]

I dont know the age of the timing belt however it looks to be in pretty good shape.

[Estaban]

couldn't hurt to turn it by hand till the marking line up and make sure.

[majicwrench]

If it runs well cold timing belt probably OK, save your strength.
Don't know what carb you have, but most have 2 low speed jets, one for primary one for secondary. A search of forum would bring em up, complete with pics and description of how to clean. Or search my posts, have gone over this several times. My books call them idle jets or low speed jets. Easily removed with carb on car.
IN a rush at the moment or I would try to figure out how to post pics again....jeesh.
Keith

[So Cal Mark]

I've seen several shorted tachs, if yours is not reading disconnect it from the coil and see if that has an effect

[Red76]

Ok, I have replaced everything on the ignition so that crosses that off the list. Going to clean the jets here in a bit. Once it warms up I can keep it running by adjusting the choke but I know that is not a fix. By the way, I think I have the Weber 32ADFA. Its the stock 2BBL for a 76.
Here are a few pics:

http://s613.photobucket.com/albums/tt21 ... nt=390.jpg

http://s613.photobucket.com/albums/tt21 ... nt=391.jpg

[Red76]

Ok, could not find the posts but I think I have found the jet that needs cleaned.
Is it part number 28 in this pic?

http://s613.photobucket.com/albums/tt21 ... owidle.jpg

[majicwrench]

Yes, that is jet, should be called idle or low speed jet. ON the primary side, the idle soleniod is in the hole the jet goes in. That electric soleniod has got to function properly. Does pulling wire off/on produce a click from the soleniod key on engine off?? ( it should) Does pulling wire off/on make any diff engine running?? (it should) And, you do need to adjust idle mixture.
Keith

[Red76]

Keith, found another clue:

http://s613.photobucket.com/albums/tt21 ... 080027.jpg

Have replaced the o-ring and while I was there the fuel filter.
I did disconect that wire while the engine was off and I could hear a clicking.
At this point I think I may be out of adjustment on the carb.
Hopfuly I can find a post with a step by step on how to adjust.

[majicwrench]

Very good. Now that jet pulls out of that carrier ( carrier has the screwdriver slot) and there is a TINY hole in that jet. Clean jet, piss carb cleaner into carb were jet goes. Did you remove idle soleniod?? Somewhere in there is a idle jet, it may be built into the soleniod. Remove and clean. Have you removed idle mix screw?? Pull it too. Now piss more carb cleaner. Now blow with compressed air, even those little can of air will work. Now put back together. Gently seat idle mix screw, then turn back out 3 turns. That will get you close enough. Start and let warm up. SHould now idle reasonable well. If it does, turn screw in slowly 1/4 turn at a time, idle should start to slow down at some point. If it does, turn it back out to highest idle, should be about where you started give or take 1/2 turn.
If idle is rough and still improves by putting hand over carb, turn screw out 1/4 turn at a time and see if idle picks up.

[mdrburchette]

Have you replaced the fuel filter? You may have a problem with debris in the lines. Are you running a mechanical or electric pump? Have you check fuel pressure to eliminate a faulty pump? Just throwing a few things out there.

[Red76]

Yes, I did replace the filter at the same time I found the bad o-ring. I don't really think its the fuel pump, I have very good performance at highway speeds. I drove it to WS and back with no issues except for the idle. I have to be careful when I start pulling parts off the carb to clean, this is still my daily driver for now and I would hate to make it worse. lol