idle problem

[Hoosierman]

Just chiming in here. A few months ago I finally was able to get my Durasparked '84 BII to start and run. Long story short, there was a horrendous vacuum leak when I thought I had it all sealed. I learned a trick from my dad who used to be a mechanic back in the 60' and 70's, I lit a cigar and blew smoke into a vacuum line. I had someone else help by watching because their eyes may pick up something mine doesn't. That worked, I had a huge leak at the base of the carb, there was cigar smoke coming from it. I thought I had the carb on tight enough, read that it required to be 10-12psi on the four bolts, and discovered with my Quinn digital torque adaptor that I had only tightened the bolts down to 4psi. I made the adjustment and now there's no leak!

EDIT: Holy schlitz my grammar.

 

[john1949]

could it be my distributor

 

[Hoosierman]

could it be my distributor

Not the most likely cause, but still possible. Can you tell us why you suspect it could be?

 

[john1949]

the motor has been rebuilt new carb new wires new coil new plugs that is the only thing left

 

[Hoosierman]

the motor has been rebuilt new carb new wires new coil new plugs that is the only thing left

I hear you, but the dizzy is not very likely, even not knowing it's history. They can be pretty solid parts, ya know. Let me help you narrow it down just a little.

Fuel pressure? Could be, but not as likely as other culprits.

I absolutely would check for vacuum leaks. If you don't have a smoke machine, get a cigar and blow into a vacuum line. Look-- I thought mine was tighter than a bull's ass in fly season, and it wasn't. Check for vacuum. Leaks, it's super easy to miss. Did you correctly tighten your carb down 10-12 psi? What sort of gasket/spacer combination did you use? Intake manifold seals? PCV valve grommet? Brake booster connection? Is your EGR valve properly blocked off or sealed? Are any of your vacuum caps cracked or coming slightly unseated when you start the vehicle?

Oh! Very important-- when you tighten your carb, don't go beyond 12 psi. They absolutely will crack on you.


Base ignition timing? Another easy easy thing to miss. Have you set the timing with the vacuum advance disconnected?

And make sure your idle circuit is adjusted correctly. Check the idle mixture screws, lightly seat them, then turn them 1.5 - 2 turns outward as a start, and then adjust accordingly. (I had this happen once). Next check your float level, your throttle plates.

Only after you've double checked all those would I ever suspect the dizzy, because those aren't exactly fun to replace on these engines. Restabbing the dizzy for timing should be your last resort before replacing.