Dual points system

[Guest Loma]

I have a 63 Ri Avanti-all stock. This car was bought by my dad new. He meticulously maintained it-he was an avaition engineer. I learned to work along side him. I have just tuned up the engine, but am experiencing weird fluctuations in the idling, and rough acceleration. I noticed my dad replaced the base plate where the points are screwed into-Does this have to do with the idling? It ran ok for awhile, then the wierdness again. I have new plugs, points, condenser, and its timed. My Avanti lives at 7,000 ft, but I have not had this problem before. Also, replaced Carter AFB with Edelbrock and adjusted it for altitude (have two Carters if anyone is interested). Any suggestions? Thanks in advance.

[Gunslinger]

How many miles are on the car? The Prestolite dual point distributor is well known for wearing out bushings and that can create a situation as you describe. The base plate moves with the advance...maybe something is not right with the installation of the new one.

The Edelbrock carburetors are excellent carbs. One problem may be the distributor vacuum advance is not hooked up correctly to the carb. The Edelbrock comes with ported and full-time vacuum ports...you should have your vacuum advance connected to the ported or part time vacuum port. The Edelbrock owners manual should tell you which is which and then cap off the other port.

Other things to look for...

A vacuum leak. Since you changed the carb, maybe it's leaking around the base gasket.

The carburetor may need re-jetting due to the altitude as well as not being matched to the cam profile of the engine. I have a Corvette that has a higher lift than stock cam and the carburetor required re-jetting as it was in a lean idle condition from being mismatched to the new cam. It wouldn't hold an idle at all. After re-jetting it ran beautifully. Edelbrock carbs, as good as they are, were not made matched to Studebaker engines, much less a 7000 foot altitude. They are pretty much a generic match to a small block Chevy or similar with a mild cam.

What size Edlebrock carb? Not over 600 cfm. Putting a 750 cfm carb on a stock small displacement engine can definitely cause poor idle quality and bogged down take-offs. It would be good at high rpms, but is a mismatch for a street engine.

A plugged PCV valve...it can cause many headaches.

Hope this helps. It sounds like something simple. Just use basic diagnostic procedures and zero in on the source of the problem.

[Paulie]

I have a 63 Ri Avanti-all stock. This car was bought by my dad new. He meticulously maintained it-he was an avaition engineer. I learned to work along side him. I have just tuned up the engine, but am experiencing weird fluctuations in the idling, and rough acceleration. I noticed my dad replaced the base plate where the points are screwed into-Does this have to do with the idling? It ran ok for awhile, then the wierdness again. I have new plugs, points, condenser, and its timed. My Avanti lives at 7,000 ft, but I have not had this problem before. Also, replaced Carter AFB with Edelbrock and adjusted it for altitude (have two Carters if anyone is interested). Any suggestions? Thanks in advance.

<{POST_SNAPBACK}>

I spent about $1,200 on my engine's FINE tunement! It included a brand new carb, ignition wiring, plugs, condenser, fuel filter, etc. I believe that the the final fix was a very, very simple replacement of the of the insulating washer between the condensor wire and its attatchment. It had a very small crack in it.

I hope that you have good luck!

Best regards,

Paul

[Paulie]

I spent about $1,200 on my engine's FINE tunement!  It included a brand new carb, ignition wiring, plugs, condenser, fuel filter, etc.  I believe that the the final fix was a very, very simple replacement of the of the insulating washer between the condensor wire and its attatchment.  It had a very small crack in it.

I hope that you have good luck!

Best regards,

Paul

<{POST_SNAPBACK}>

In retrospect, I should have made my point more abundantly clear. AFTER the $1,200 tune-up including all sorts of checks for vacuum leaks, I still had problems with my car. It would start and run fine for a while until the engine warmed up. That's when the engine would start its coughing and stumbling fits and finally dying out, especially when I tried to give it some throttle acceleration or worse when stepping on the brake while at a stop. THAT is when my shop finally discovered the very small crack in the insulator between the condensor wire and its attachment. I have had absolutely no problems since its replacement six months ago.

Best regards,

Paul