Well crap, scratch all that I've said. I guess I missed that somewhere.

I don't like carburetors anymore. Never thought I'd say that.

 

With all the crap they're putting in gas, it's hard not to think it's a conspiracy to get old carbureted cars off the road!

 

At this point, I'm really thinking it's either the carb or wiring. Is there any way I can check an edelbrock while it's hooked up to see if it's vapor locked? What I'm dying to know is, aside from the ignition coil, is there any other electric stuff I can troubleshoot while I wait for my heat shield in the mail??

 

correct me if i am wrong but i have read through the whole thread and don't see how the fuel pressure is regulated to the carburetor. just my experience says if the carb came from the auto parts store its probably not very good to start with. Again if i missed something let me know. I did miss the first post about running four psi but were is that reading taken from.

Any choke adjustments made. make sure the fuel has proper ventilation to.

 

I'll step out now and maybe a Carb/Duraspark connoisseur can help. You may check the PO's wiring by THIS diagram.

 

There is a fuel regulator and gauge on the firewall. The carb is Edelbrock...I have read a lot about how they are prone to heat soak, but I am trying to keep it if possible. As far as choke goes, it is not hooked up. Just running it completely open. Could that be part of my issue? I would think that a hot engine does not need to be choked. Then again, I'm a noob when it comes to carbs, so it might be as simple as that.

 

Your right just be sure its not coming on hot if its free to move open or closed. if the fuel tank has to much fuel or can not vent it will then expand as it gets hot and cause possibly a no start.

 

Good to know, I'll double check. Somebody suggested running without the gas cap in case pressure in the tank was an issue. That didn't help.

Is it possible something like spark plug wires are over heating? Aside from the coil, what other electronics are prone to heat soak?

 

well the big thing is find out what your missing if your loosing spark you need to prove it. from what i understand the truck is set up on a fuel pump in tank. so when the truck will not start take a fuel pressure and volume reading as close to the tank as you can get. i would not think a stock efi setup would be carb friendly. I have been reading as quick as i can but i assume you have a spark tester and a volt meter.

To my knowledge the only engine still carbureted in 1987 were the 351 and 460. This may sound ridiculous and dangerous but if it came down to it you could bottle feed the carburetor when it wont start.

 

I'd first eliminate the frame mounted filter.

Questions:

(1) CFM rating on the carb? (e.g 600, 750)
(2) Is the regulator on the feed or return loop?
(3) Are the fuel lines 3/8"

I'm not crazy about that 4 psi either................

 

1) 600 CFM
2) There is no return loop. The regulator is on the feed, just before the carb
3) Yes, they are 3/8
4) Why are you not crazy about 4 psi? This gets to the meat of my question. I know that too high and you'll flood. Too low?

 

not to double post but well to get to a good starting point get the truck to act up and check for spark. then check to be sure it not flooding out try giving it a very small dose of fuel does it fire. when it will not start work the butterfly back and fourth is fuel squirting into the barrels. If you even have a pin size hole in your fuel system its going either leak gas out or air in.

 

I'll check for spark in the morning. As far as fuel goes, it DOES squirt into the barrels (is this good or bad?). When it's hot, it will not start, regardless of whether I hold the pedal down, don't hold it down, feather it, etc. Just won't start. I bought 10 ft of fuel hose and am going to replace that shortly as well.

 

Edelbrock will tell you ~4 psi is "ok" for their stuff but you have an EFI conversion and the system may not be 3/8" thru to the pickups in the tank.............the lack of a return will also tend to "vaporize" newer fuels (which have higher boiling points to begin with)

what is your fuel pump setup ?? (Optimum would be an upgraded electric)

 

yes you want a good pump shot from the accelerator pump. that tells me either the engine is flooding out or that its getting plenty of fuel but something else is wrong. when you check for spark check off the coil and at a plug wire. just remember if it is flooded you don't want sparks near the carb or any fuel.
when it will not start does it crank faster than normal.