Hi everyone! A newbie from north of the border, and happy to be here. Hope everyone here is enjoying their Mopars this summer. Riding in Chrysler cars from a young age, and having a few of my own when I was younger, I just bought myself [May of this year.] a 1966 Valiant 2 dr. htp.,auto., with 36,000 original miles, with a 170cid, "leaning tower of power", with a Carter 1 barrel, to take me into retirement. It was stored indoors for a good part of its 52 years, and is all steel. It was painted once in its life. A great car, but I've got an issue, and I'm looking for some help, here. On hot days [80+ degrees] the car will intermittently bog while accelerating at cruising speed, and when I ease up on the throttle, it runs fine. It never stalls when it does this. Sometimes it won't repeat the concern for the rest of the ride-other times, it will. It seems to run okay in the cooler weather, but I haven't had it long enough to narrow it down to all the different temperature ranges. It came with a new fuel tank and sender, hoses, fuel filter, recently rebuilt carb, overhauled distributor, points, condenser, ballast resistor, intake and exhaust gaskets,vacuum hoses, among other parts. The fuel pump is the original rebuildable type, and I checked the fuel flow while cranking it over, and It has a lot of volume. Could it still be the pump, and are rebuild kits available? Anyone come across this before? Could today's fuel be the issue? The last classic car I owned was 35 years ago. Any help would be great. Thanks.

 

First of, welcome to the forum.
Yes today's fuel can cause drivability problems and it's hard on fuel hose and rubber parts in the carburetor.
with that said I would check timing and verify mec and vac advance, carb, make sure its squirts fuel at the time it gives you problems and verify the choke is fully opens. Are fuel lines to close to heat source and I would replace fuel filter even though it might be new and seem to flow fuel. Also verify condition of all rubber hose on car.
You just have to rule out everything one thing at a time until you find the problem.


I have seen the mec. advance in a distributor stick in older cars and run on vac. advance until the throttle was opened.

 

tm -

Hard to say, but based only on what you described, the possibility of vapor lock has to be considered. While it's usually a failure to start in hot weather thing, the fuel could be vaporizing in the line. You could try insulating it fuel line where it comes near the motor or just rerouting it.

Archer

 

I'm going to add that just because work was done and parts were replaced that all is good. New parts today can be junk out of the box! So you still need to go over everything and don't make assumptions based on the fact that parts have been replaced.

 

Welcome to the site.... Looks like you got a lot of this covered.. Yes fuel can play a part... These cars ran lean even back in the day.. So getting them a little fatter can be challenging.. I would suggest putting a fuel gauge on it and check the fuel pressure when you drive it... The flow might be good, but maybe the pressure is not good?

Keep us posted....

 

Thanks to everyone so far. I'm going to start with replacing the fuel pump-it's the only original part that's left regarding the fuel system, and they're not expensive. I can't get the rebuildable type anymore, so the replacement is a sealed unit, but before I do this, are there any tips/problems I should be aware of with the change-up part?

 

Loosen the mount bolts slightly, if the camshaft eccentric has the pump in a stroke it will feel tight. Turn the engine by hand until the pump feels loose, this will make aligning the new gasket and pump easier.

 

Thanks, Dan--I would have overlooked that little detail. You guys are a great source of info! Thanks!

 

Also-anyone up here in Ontario have a 1 barrel Carter carb for a 1966 slant six that they are willing to part with? I wouldn't mind having a spare.

 

I would look at replacing the carburator with one made for todays fuel types.

 

What would that be?

 

Thanks to everyone on the forum--it was the fuel pump! The 52 year old pump was tired I guess. I drove it yesterday in the hot weather for 4 hours with breaks in between, and it didn't bog once. I plan on driving it to the city next week [suicide mission???] and that will be the real test. Thankfully, I have CAA, just in case........

 

Thanks for postings the results, in the future please post questions once.
thanks