SOLVED: HELP WONT START

[Neospartan]

1973 C10 350 long bed step side. All original with CA smog and quadrajet carb.

When I try to start it just turns and won't start until I hold the pedal to the floor then it back fires and when I release the pedal it dies.

I replaced the timing chain, problem didn't change

I rebuilt the carb, problem didn't change. I'm out of ideas please help

[Jason S]

How is the ignition system?
Are you getting a good spark as the engine turns over? You can pull a plug, clip a wire to the plug threads and run it to a ground (i.e., the block)

1973 engines came with points ignition.
Does your truck still have the original points distributor? If so, you might inspect and/or replace the points and condenser.

[Neospartan]

I have new plugs and wires and new distributor before the problem and I have checked the spark with the spark plug light tool

[Neospartan]

Actually I haven't replaced the coil canaster, also I haven't replaced the fuel pump, but when I pour gas down the carb it still doesn't start. It will only start and run rough then back fire and die when I hold the pedal to the floor.

[rich weyand]

You have a new distributor.  Have you set the timing properly, with a timing light?  Do you know that your timing mark is properly located?  Did the problem start with the new distributor, or was it running properly for a while after the new distributor?  Are you sure the distributor is clamped down properly and hasn't drifted retarded?  Did you check the timing with a timing light since the problem started?

[Neospartan]

Thank you for the comments.

when I replaced  the distributor I set the timing with a light, and after a year of it being a daily driver it started to become hard to start and hard at idle, and now for the last six months it won't start, and when I hold the pedal down it starts but I have to hold the pedal to the floor to keep it running. Then it will back fire through the exhaust and up through the carb and die. The problem didn't get sever until after a year from when I replaced the plugs and wires and distributor and cap, and set the timing with a timing light. 

I also can get it to run long enough to get the timing light on it.

[Jason S]

Does the fuel pump have good volume?  Fuel filter clean/clear?

HEI or points distributor?

[Neospartan]

Points. And I will check the pump when I get home... But I've tried starting by pouring gas down the carb and using starter fuild. Still didn't start. And back fired through the carb.

[Neospartan]

Is it possible for the distributor to mess up after a year where It throws off the timing so it won't start? but then why would it start when the pedal is pressed to the floor?

This link is the video of trying to start it

https://vimeo.com/116894792

[Jason S]

Is it possible for the distributor to mess up after a year where It throws off the timing so it won't start? but then why would it start when the pedal is pressed to the floor?

Yes.  Points wear out; condensers and points should be replaced as a set. Usually, I'd replace points and condenser at least once a year (every 8k-10k miles).  Worn out points/defective condenser can result in hard starting, rough idling, misses, random dying, etc. 

Looking at the video, is that fuel puddled on top of the carb?

[Neospartan]

Yes, the video was taken right after I pour gas down the carb and it began bubbling back out.

Update: check the fuel pump when I got home, fuel pump is pumping well. Attempting to check the vacuum on the carburetor, gauge says zero vacuum at base of carburetor. Not sure if I'm doing it correctly, or if I have a leak.

[jaredts]

Not sure why anyone would buy a new points style distributor, but I guess you have your reasons.  If it was me I would slap a hei in there and be done.  Or you can change the points, condenser, check dwell and all of that other stuff that will take more time and money than hei.

[Dr_Snooz]

Not sure why anyone would buy a new points style distributor,

I was thinking the same thing. It's almost like, "sorry, we can't begin troubleshooting until you get rid of those points."

[VileZambonie]

Unless you are preparing to sell your 100% original truck for $1 million dollars ditch that points system yesterday.

[Dr_Snooz]

Is it possible for the distributor to mess up after a year where It throws off the timing so it won't start? but then why would it start when the pedal is pressed to the floor?

OP, points are finicky, hard to adjust and notoriously unreliable. And yes, it is possible (and common) for a points distributor to mess up like you describe. Points just magically go bad and cause all kinds of fun. My first Honda had points and it was interesting for the first three months until I realized how bad that setup is and converted.

If it isn't already, an HEI upgrade should be at the top of your to-do list. There is a lot of info out there on converting, and a Google search for HEI conversion brings up many, many hits. Here is one good (possibly overly-detailed) how-to: http://rmcavoy.freeshell.org/HEI.html

Specific to your issue, check your points for pitting on the contact surfaces. Sand or file off any pitting to within tolerance. Make sure that the contact surfaces stay flat for full contact. Then check the gap, adjust, tighten the lock screw, curse when you realize that the gap has changed, wash, rinse, repeat. Cross your fingers and hope. Post #5 here has a very detailed description of point function and adjustment: http://www.hotrodders.com/forum/setting-points-sb-chevy-28120.html