76 F-250 Trailer Special. 460 Motor, C6 Tranny. Non-California, all stock. no EGR, etc

would not start in morning. pump the pedal, turn it over, turns over fine, just won't start
1. have spark (not sure how strong)
2. changed fuel filters (at the fuel pump and carb)
3. put on rebuilt carb (motorcraft) - no change
4. choke works (not that I need it in Arizona in June)- its closed in morning and opens up when warmed up. stove pipe seems ok, no vacumn leaks I can see- fixed them all before getting emissions inspected
5. timing is spot on, emissions are good - it passed inspection after timing it and tuning up the carb
6. there is a big flat spot in the carb on acceleration- if that gives any hints
7 plugs are all gapped and new. was a bit of oil on a couple of the old plugs but nothing serious. Will put rebuilt D3 heads on soon. no points - duraspark.
8. air filter clean. Have a nice 76 lincoln towncar air cleaner assembly with the oil filter looking thing on it
9. when I squirt a bit of fluid in the carb, starts up fine, and then runs fine all day, starts no problem for rest of day, even after sitting during work
10. I do have a problem with the dual tanks. Only front tank works, haven't got around to figuring out if the problem is the switch on dash or solenoid. The gas guage does not work

Ideas? weak fuel pump? problem with the rebuilt carb & bowl draining out overnight? (I would think cranking it would get fuel up there eventually so I doubt it), weak coil?

thanks for any help you can offer!

 

Since you say it will run fine all day seems like it wouldnt be the fuel pump, but I would change it, and put a clear inline filter between the carb and pump to see it its fuel delivery and just not priming or somethign.

 

accelerator pump

 

It sounds like the accelerator pump to me too, with the engine off remove the air cleaner and open the throttle linkage by hand at the carb, there should two solid streams of fuel squirting into the intake.

 

yep,that was it. Thanks guys! wonder how long that "rebuilt carb" was sitting on the shelf that the accel pump was bad. AutoBone & O'bliemy's - land of bad fitting aftermarket parts. Just took a nice looking one off a 76 Lincoln towncar at the JY - will rebuild it myself and put her on. Put, then again I have a TorkerII intake and a 750cfm Edelbrock sitting in the garage- just haven't figured out how it will pass emissions testing - I can put it on in AZ, just don't think the CO2 and hydrocarbons will fall in the acceptable range.

 

ok, so it worked for a day- .
i opened up the carb, noticed the accelerator pump didn't have the pin in it, so it wasnt' working at all I gues sloppy rebuilt- quality of aftermarket stuff nowadays is really bad. Anyway, it started when cold after i replaced it and put fuel in the bowl. but today, in am, she wouldn't start. Any other ideas? I did notice that the giant flat spot in the carb when I punch it went away- so we have 1/2 the problem solved.
1 do you use the middle position for the accelerator pump when putting in the pin?
2. which hole do you use on arm that goes to the throttle linkage?- the upper or lower one- or does it not matter if you adjust the nylon bolt?
I noticed when I opened up the carb, the bowl was pretty low on fuel. the floats are good (no holes). But really, when it cranks, it should refill the bowl, shouldn't it?