what happened???

Installed a cam, lifters, pushrods, timing chain on my sbc a week or so ago, The jeep was running fine. I took my daughter for a ride lastnight and she wanted me to go fast, so I gave it all it had running through the gears and it ran fine, pulled hard. When we came to the next stop light, the idle had dropped to 600-650 rpms and idled rough. It idled at 800-850 before this just fine. The carb does have a little play in the throttle shaft, so there is a small vac leak. What do you think would cause this to happen?? I tried adjusting the carb as soon as we got back home with not much change. I did get the idle to come up to 750-800 rpms but it fluctuates from 600ish to the 750-800 mark.. Any Ideas!
The carb has been rebuilt twice in the last few months, Oh,,, I did put a dwell meter on it lastnight and the dwell is at 28 now when it was at 30.

 

thanks, that was my plan of attack but wanted to run it by you guys and see what you thought. I dought I will be messing with it today though. I welded for a friend yesterday and think I burned my eyes, I don't understand how though because I wore the face sheild. anyway, maybe later today. thanks for the input

 

Potato juice will remove the flash burn. Learned that from an old welder and it works.

 

Potato juice will remove the flash burn. Learned that from an old welder and it works.

How does that work?? I mean how do you apply it to your eyes? because I will try it for sure.

 

I just juice a potato. Use like eye drops

 

Cut in thin slices and put over eyes, draws the heat out. Could go to Doc. and ask for tetracaine.

 

thanks, I will try the slices. The potato eye drops don't sound fun.
thanks guys! Im going to try and tune the jeep in tomorrow, I went out to the garage to try but the eyes were bothering me too much.

 

True statement know this from experience, use a darker shade lense i use shade 11 on carbon steel an sun glasses combined with shade 11 when welding aluim. to get a 12 or more shade.

 

Someone a while back stated that this site is amazing. I must say, that is a true statement. I used the slices of potato lastnight and I can see today. The light doesnt hurt my eyes like it did, and it isn't watering near as bad.. That was amazing, thank you so much...
I used my friends facesheild and was wondering if he didnt have a dark enough shade as well. I will tell him to get a darker one. thanks again

 

Last time I had a problem similar to yours with a sbc it was the distributor advance hanging up because the upper plate on the Accel dist was loose on the shaft so it cocked a little bit and hung up on the springs, not allowing it to return to idle position. Not something you would usually suspect and the last Accel product I bought. That was 15 years ago.

 

thanks duff. Im going out to play with it in just a little bit. I will def look at the vac advance. Im curious as to why the dwell would change from 30 to 28. the WOT run shouldnt have caused the points to ware down suddenly like that would it. Wen I had everything apart for the cam, I looked the dist over and the shaft and everything seemed tight (no play). Ill let ya's know what I fing out later on.

 

When you changed the cam and timing gears, did you use an offset key, or bushing that may have slipped?

 

No, we installed the chain in the standard timing position, which was the O on the sprocket per the directions. I looked it over today and found that the vac advance must not be funtioning. the timing was at 12* btdc with or without the vac hooked up. I took the cap off the dist and trying to move the plate clock wise and counter clock wise I could only move it about 1/16", is that normal. If so what else would cause it not to funtion. Do I need to take out the dist and really look it over? It runs fine except at idle it is rough and runs rich, driving it, if you give it the gas it gos just fine but try cruising at say 25-35mph and it not right.. runs kinda rough, has some hessitation until you increase the gas, then it runs fine again. just at idle and at steady slower cruise speeds does it act up. It would be nice if I could fix this one and not have to buy a new dist.

 

If you're sure its the vacuum actuator you can get one from O'Riellys, Napa, Auto Zone, any number of parts stores.

 

well, im not sure, but it used to funtion before the cam install because i was always playing with the timing. Id set it at about 10* plug the vac line in and it would go off the timing tag. now it stays right at 12* and don't move with the vac line hooked up or not. thats all it could be isn't it?? If so I will get a new one. o'riellys is right up the street.

 

oops sorry wrong key
.

 

Are you going to take the advice of a electronics tech or a welder? Ha just kidding, lens shade has everthing to do with keeping your eyes from being burned,if shade did'nt matter then why put on a shield. Reflection,an the smallest crack in your face shied will cause problems just as not dark enough lens will.