My '68 has a 73 460 in it. Replaced Dizzy, carb, plugs. Still misses at idle and doesn't accelerate well. The more i advance the timing, the more it misses but i get better acceleration. When set to 12 degrees BTC it idles fine but no acceleration at all! Where the timing is right now, it misses at idle. Accelerates great till about 50. If cruising at 50 and you punch it, it accelerates slowly. If i advance timing further, it hardly will turn over when starting. Someone said i may have the dizzy off by a tooth. Would that cause the above problems? I did replace the cap and rotor, but it ran very very bad so i took them back. My plug wires are pretty old. Would that cause the above problems?

 

YES, i know by experience, just take off the valve cover get the #1 cylander to absolute TDC so the both valves a closed and make sure your dist is pointed at the
#1 plug location, easy way is mark the location on the base and take the cap off so you can rotate it evr so slightly so it still points to the number one cylender

 

Replace your plug wires!!!!

They crack over time, loose their spark to the block and gain a great deal of resistance....I replace mine every year in my truck and every 6 months in the Beetle.

 

re check tdc and replace wires, old wires can sometimes cause you problems and they are not that expensive.

 

how are the plugs? did you gap them to .035" ?
they can appear fine but the electrode inside the ceramic can be toast.
you can get some spark plug wires like duralast and whatnot that are cheap as hell and come with a warranty also! double check the firing order, 15426378, and then set your timing with a timing gun. and make sure that rotor is pointing to slightly before #1 slot at tdc. is vacuum advance on ported or constant vacuum?

 

replaced plugs (gap at .035) and wires. New coil too. Only way this thing hauls *** is if the cap is rotated all the way clockwise (advanced?) Can hardly idle though. When set to 12 degrees btdc it runs fine until you gun it then it just bogs down. Do you think i could have the dizzy off a tooth when i dropped it in? Is there any harm in running it advanced and turning up the idle so it doesn't die at stop lights?

 

If the truck is at idle and you advance the timming the rpm should rise so are you shure you advanced it. Is the vaccum advance hooked up wile you are setting the timming. You can be off a tooth the spark plugs don't know what post on the dizzy cap they are hooked to as long as the timming is correct.

 

Vacuum advance is hooked up. The hose to the carb has plenty of suction. I'll check the vacuum advance on the dizzy.

 

Yes vacuum advance is hooked up while timing it. Should it be hooked up?

 

Unplug the vacuum hose on the vacuum advance. Plug the hose. Set the timing and then hook the hose back up.

 

I see you live in Washington from your profile......at what altitude?

Timing at altitude often requires advancing the timing a few degrees....I'm at ~5800 here in Boulder and mine has to be advanced a bit from the stock tuning to run properly.

 

The timing must be set at a specific rpm. This should be on the emission sticker on the valve cover. As DavidB says, the vacuum advance hose must be disconnected from the advance, and the hose plugged. A golf tee is handy for this. The engine should be up to normal operating temperature as well. If you don't have the specs, someone here will. Good luck!

zenmaster

 

also, make sure that if your vacuum advance is setup for manifold vacuum, that it is indeed plugged into manifold vacuum. If it is set to carb vacuum, it must be plugged into carb vacuum.

They make vacuum advances that operate both ways, i do not know which where stock for your setup.

If it is meant for carb vacuum and you have it plugged into manifold vacuum, the advance will essentially be functioning completely opposite how it was designed to!

Also, on the topic of being "off a tooth," I hear this all the time. While on quite a few newer engines, especially distributorless or engines with a cam sensor you can mess up the computer with the cam gear/distributor gear location, it doesn't matter on these older engines. I am willing to bet that on every Carb'd engine, the cam gear/ distributor gear location does not matter at all. The exception is if the vacuum advance can sticks out and smacks the valve cover during the rotation or something.

I had a friend, actually an old boss, that spent at least 4 hours literally trying every tooth on the cam gear to get his car running right. Of course, it would always run like **** every gear. I kept telling him the problem lied in the advance, he refused to believe me. I tried to reason with him that he was spending all his time for naught because the distributor did not care which tooth it was on. He told me that I "didn't understand the basics." In hindsight, I realize that he was just frustrated and not trying to insult me. At the time, i was pissed that he accused me of not "understanding the basics." So I just watched. 4 hours later, his knuckles were bleeding and he was steaming mad, I walked over, asked what was wrong. "Its still on the wrong F-ing tooth and I can't find the right one." I pulled the vacuum hose off of the intake manifold vacuum tree and plugged it into the carb vacuum port on the back of the carb, set the base timing, and the engine ran great.

I told him next time he insulted me for trying to use reasoning and logic to solve a problem, I would wait for 4 days, not 4 hours.

 

Also make sure your idle mixture setting is proper. You need a happy medium of setting the idle screw, idle mixture, base timing.

 

here is where i 'm at now. I plugged vac adv line, set to 12 degrees. Now as long as i keep the line capped, it runs like a bat-out-of-hell. Idles ok to. I'm thinking the springs in the vac adv are too weak or strong and causing it to advance wrong. For now, i'll just leave the line capped.
Haven't played with air/fuel on carb yet. im around 300 feet altitude. i work in portland oregon which is sea level.