I have a recently built 400 with Edelbrock 1406 carb, new gas tank, fuel lines, fuel pressure regulator, fuel pump, fuel sender, clear fuel filter near carb. I was just bragging about how great this truck has always run. Figures. This weekend I dropped the tank to repair a fuel line that was leaking. However, after doing so, I made two trips to the grocery store, about 6 miles round trip, with no trouble. Truck ran great. I decided to drive the truck to work this morning. Started up great, warmed up in the garage, and set off. Still ran great until about 4 miles away, then started hiccupping as though it was not getting gas. I know the tank was over half full. It was bogging down and lunging until it finally cut off. I guess this was right about the time it would come to operating temp. Anyway, I could get it started right away with clutch in then it would immediately start bucking again and die. Sometimes it would not start for a minute. I was able to turn around and make it back to the hood. About a mile from the house it started running fine. No more issues getting back in to the garage. After work I started it back up. fired right up, no problems. I let it idle for about five minutes, and revved several times. Pressure regulator read steady at 5 psi. Decided to test drive. Did not make it out of the neighborhood before it started again, just as before. Ran great until then.

Now, most fuel related items are new. No rust or debris in clear filter at all. I have never had any problems with vapor lock, plus it was only 25 degrees out. It's the same gas as before I dropped the tank. I did not remove before I dropped it. Fuel sender sock was new and clear. Choke has been working properly. I manually disengage it by pumping accelerator before I leave. It acts like debris in the carb jets, or water in the gas. I don't know enough about carbs to get in to it and check it out. Any ideas what would cause this? I'm getting really ticked at these issues I've been having lately.

 

Sounds like it could be flooding. The next time this happens, look down the throat of the carb with the engine still running. You'll see fuel dripping down the throat if it's flooding.

What carb is this?

 

I have had carb icing problems that acted similar. Usually would happen when using an open element air cleaner in weather 40* and below,
The venturi effect in the carb causes the moisture in the air to condense and freeze, forming ice in the throat of the carb. Shut it off for a bit, let the engine heat melt the ice and you are back on the road...until it does it again.
I first noticed it happening when the throttle got sticky. Apparently the ice was forming on the butterflies and throttle shaft, locking them up. Again, after setting a bit the problem vanished.

I cured the problem by running a stock type air cleaner assembly, with heated intake air.

Roger Carter

 

^ plus one on the icing idea . I have seen a few icing issues in the past . Worth looking in to .

 

Well, I tried to start this morning, but did the same thing from the get go. could not keep her running. I removed the air filter. Choke was closed. I could not notice any gas being spurted in to carb. I removed fuel line from carb and placed in glass jar. It pushed out gas for a few seconds, then stopped. None after that for several turns. I pulled inline fuel filter. Had a couple small pieces of debris, but had plenty of flow. Cleaned and reinstalled. Same results. I then bypassed the fuel regulator and gas came out of the line from pump just fine. I figured the fuel regulator was preventing the gas from passing. however, I then bypassed the regulator and connected line from pump to carb, but had same results. It sputtered at first and gas sprayed up from carb over a foot when I opened with my finger. After a few seconds, no gas. I could not see any gas being shot in to carb, from either jet. does this sound like the jets are clogged?

 

Edit, nevermind, I just read your last post.

 

Gas shooting up from the carb makes no sense unless the floats are stuck or the fuel line pressure is too high for the floats to work properly. Either way you can get a considerable squirt of gas out of the bowl vents.

The fact that you get no gas through the jets does make it sound like the carb is gummed up.
When you work the linkage with the engine off do you get a squirt of gas into the barrels from the excelerator pump?
What brand of carburetor is it?

Also, the fuel pressure regulator should provide a steady supply of fuel and never taper off to no flow with the fuel line open-ended like that.
I think you got a decent dose of gasoline varnish in your system and it gummed up the works.

 

Thanks for the quick reply. When I work the linkage and stare down in to bowls, I do not see any fuel squirting out as I normally would. I guess it does spray occasionally because the truck does start and run sometimes. Plus, the spray I get straight up occasionally.

I don't get why the gas stopped flowing when fuel line was removed from carb and put in a jar either. Looks like a carb rebuild is in my immediate future.

 

Yesterday I needed to move the truck in to the driveway. It took several seconds to start, but once it fired up she ran great. No stalling. Weather has been quite warm if that is a factor. I pulled in to driveway and continued to idle for nearly ten minutes, revving engine and all. Motor was getting fuel just fine. Never hesitated. I did not want to take her down the street in fear of not getting home. Strange thing is, the new fuel pressure gauge read 0. The regulator just before the gauge is set to 5.5, and the gauge has always read properly. I'm assuming the gauge is bad. Anyway, I monitored the clear inline fuel filter while working the throttle linkage(located right before the pressure regulator). It nearly completely emptied, then refilled, then repeated. It did this at idle and under throttle. Is this normal, or should it stay full? I'm wondering if the problem may be the new fuel pump.

 

You are probably on the right track in suspecting the fuel pump being part of the issue.
I also suspect the carb is dirty. Edelbrocks hate dirt and the last time I had carb issues it was caused by tiny chunks of rubber from the fuel lines.

 

I just wanted to wrap up this thread. I went back through everything I had done and found that when putting the tank back up, I pinched a section of fuel line between the tank and the bed, restricting flow(idiot). Anyway, I figured that would solve the problem. When I tried to start, it made some God awful noises and smoked gray smoke from exhaust very badly (never smoked at all before). It was also backfiring through the exhaust. Could not keep it running. Pulled the air filter and saw gas was spewing up from all over the carb, mainly from around the square-ish holes beside the metering rod covers. It was pouring on to intake manifold. Anyway, when I pulled the carb, everything was gas soaked. Gas was leaking in to exhaust manifold, causing the backfires and smoke.

I did rebuild the carb this afternoon. I don't know why I was so intimidated. It really was pretty simple and straight forward. My phone camera was my best friend, though. Especially when reconnecting the linkage arms. I had a calibration kit, but decided to keep the same jets/rods right now. Everything looked so good and clean before I started. I could not imagine anything was wrong with it. I really did not have to clean anything much. I think the problem was one or both floats were stuck, so gas was not being restricted, and it flooded the bowls. Truck started right up afterwards and acted properly. Ran great. I'm happy again. Thanks all for the input.