Peva

Title pretty much says it all. Is it the nature of the beast, or does it indicate some maintenance or new parts needed in the fuel or ignition systems?

Previous owner replaced carb with manual choke model - choke appears to work (closes completely), starts fine in moderate temperatures. Is ign. coil possibly weak? Points? Disty. cap? Ign. wires are relatively new. Need to check spark plugs. New fuel pump last year (old one leaked fuel) - no change in cold start issue.

If it’s just the nature of the pre-electronic ignitions or fuel system, then I don’t want to waste time/money troubleshooting a non-fixable problem.

Comments/suggestions appreciated.

Redneck11

My choke doesn’t properly function on mine but I richened it up a hair and I feather the gas for about a minute when I crank it and I don’t really have any problems

Redneck11

One thought I just had. Does your 85 still have the feedback system? I gutted the feedback system from my truck and have an older carb and a vac advance distributor I dont know if that would make a big difference but you never know.

Peva

Thanks for the replies, RN11.

You're saying you have to crank it for a minute before it will start? Yeah - that's hard on a starter (and battery). That's what I'm trying to avoid.

When you say "feather the gas", you mean you're moving the pedal to pump additional fuel into the carb, or you mean you're just trying to find a midway position of the throttle that it likes?

I assume my disty is vacuum advance - will have to take a look. What do you mean by "feedback system"? I assume mine is factory setup other than the replaced carb., so if it came with the feedback system, it would likely still have it.

Maybe it is a matter of not enough fuel. I will take another look at the choke - perhaps it is not closing all the way. Also will test the accelerator pump.


Is anybody able to say one way or the other for sure that even if everything is 100% up to snuff, cold (below 35°F) starting is difficult and requires starting fluid? That would help me decide how hard to work on solving it.

Redneck11

I bump the starter and it cranks but I have to feather the gas for a minute to keep it running

Redneck11

The feedback system had sensors in/on the carb, a coolant sensor, vacuum sensors, and other stuff that ran to a computer that messed with the timing advance rather than having a vacuum advance.

Peva

Thanks for clarifying on feathering the gas. Makes sense now.

Will have to look into the feedback system. Not sure what’s there and if still intact.

vjsimone

Something else to check is your EGR-Valve (if you still have one), if it is not closed completely, it will allow Unmetered Air/Exhaust Gasses to enter the intake while cranking/initially starting which will lean out the F/A mixture, making it harder to start in cold conditions.

Cold fuel is harder to ignite, this is why most carburetion design is to dump lots of fuel into the intake for initial start. (full choke, etc) So a strong/hot spark is desired for cold start-up.

If you have an accelerator pump carb, you would want to inspect/adjust for maximum squirt.

Peva

Thanks VJ. Will verify the EGR is working - I had not thought of that. Will also check accelerator pump and adjust if needed, and check of plugs, ign. wires, points, and disty. cap and rotor and replace as needed. Will report back with results (might be a week from now).

vjsimone

Also, as a test, disconnect the vacuum line to the EGR-Valve and plug the line.