Dauntless v6 running strange

Ive been running my dauntless from a 69 v6 for years now and know whats normal and whats not. Its been running strange latley and i would love some input from those that are much smarter then i.

I just gave it a full tune up because it kept cutting out. It ended up being the distributor cap/rotor. But i changed the cap, rotor, points, condensor, plugs, fuel filter, and cleaned air filter. I set the dwell to 30 degrees.

Latley its been running weird. Granted its colder out but it is running different then past winters. On start up it needs choke on, then off then back on then off then back on ect til it runs for a few min. Its been popping and backfiring thru the exhaust on deceleration and i believe hicups thru the carb when stating from a stop. In all honesty it runs great at cruising speed.

I checked the timing which was 0 degrees so i set it to 5. re adjusted the carb to the highest vaccum on the leaner side. noticed the vaccum was only 16lbs. I checked the intake, carb gasket, vaccum advance, booster, pcv and all vacuum lines several times with using the propane trick.

Is it time for a carb rebuild? Its been about 10 years. I think these are odd symptoms tho. Is it possible that the consensor or some other ignition component during the tune up was defective?

 

Valves? Done a compression check?

 

Thats what im worried about. Something internal. This is an old motor!

 

Sounds like carb issues to me. Especially if it's a ten year old rebuild. Chances are you might not have the ethanol-friendly rubber bits in there, from the last rebuild kit. And things have dried out/decomposed/fallen apart, and possibly even got some rubber bits stuck in some of the passages.

 

I would start by looking at fuel delivery and vacuum leaks. Symptoms kind of point to that if no luck then revisit ignition. If no luck then perform a compression and leak down test.

 

So my next step would be a carb rebuild? I could easily do a
Compression check first But after that should i do a carb kit???

 

I got a bad condenser on my last tuneup. Second new one made a huge difference.

Tim

 

Green shirt where the symptoms at all similar? Unfortunatly i already threw the old one out. Ill try some marvels. I do put a quart of lucas in everytime not sure if thats similar?

 

Are you running a PCV valve? It might be stuck open or worn out. Plug that vacuum line and see if it makes a difference.

 

Yes, they were. I also replaced lots of other things like coil, plugs/wires, ballast, cap, rotor and ignition switch. I kept every old part and started swapping bits in/out as it seemed nothing worked. Then I started over by replacing things that were new with things that were "bad". Old condenser in and everything worked. I swapped back in some of the other bits just see what I could return...coil and wires/plugs definitely bad, cap no good and points bad; symptoms all returned. Too hard to reinstall the old ignition and it was cheap enough so stuck with it. Ballast was okay so that's in the spares box.

Tim

 

Hmm ya know i never messed with the ignition coil or ballast resistor. They are both old but have always been fine. I pulled out the pcv valve and it rattles like it should ao i put it back in. For the 3 dollars i guess ill put a new one in. Ill buy another condensor too. Also a compression test and carb kit i suppose.

 

If the resistor was bad it wouldnt run. At least mine didn't