December 15, 2011

Is it the fuel pump? The carb? Floats? Lines? Filter?

As you'll know if you've been following along, we've spent several days (and many hours)trying to get the beautiful '56 Chevy running - and running properly. Being a scientific thinker and understanding the value of troubleshooting, I have been though every system on the truck in order that it would run as it should. After many different attempts at troubleshooting, we finally got it running, reasonably well, but only while introducing fuel through the carb top.

After rebuilding the carb, trying it with and without the filter, pushing air through the lines, checking the fuel pick up and everything else, it was till only pushing a small amount of fuel out of the pump - and not enough to reach the carb! This is where my love of cars turns into a seething hatred for all things GM!
So what the hell? I know a fuel pump puts out 3-5 psi, so more than a dribble should come out - right?! Right! The odd thing was that when we hooked up a vacuum to the line, we where able to get gas to flow fairly easily.

Then, the proverbial light bulb! There's a short flex-line between the cab and frame lines and it's really the only part that hadn't been removed and checked. So up she went on the BendPak. Sure enough, it didn't even take a second to see that the GD piece was kinked. BAM. Major issue found!

So I bend the lines until the pressure was relieved on the flex-line portion and went back to the engine bay to see what would happen....sure enough, the fuel is now POURING out of that line and into the pump. But even so, it still wouldn't pump all that hard through the old pump. So back on went the new pump, this time: success, now THAT'S what 3-5psi looks like!
But even so, it still ran and bogged as though it wasn't getting enough fuel into the float bowls. So off the carb came for the THIRD time! And here's what I saw:

The float drop measurement - which I just checked when I rebuilt the carb last week - should be 1 3/4". It was more like 2 1/4"! So, after setting it the first time I must have bent it when I opened it up to check the gasket placement....sometimes you can't win for loosing!

To be PERFECTLY HONEST, I have NEVER run into a situation like this in 35 years working on cars. After you learn COMPRESSION-TIMING-SPARK-FUEL things normally move along.

Sure, sometimes you have to troubleshoot every system on your way to get it running, but this thing has been absolutely backbreaking!! It's also been burdensome, exhausting, fatiguing, formidable, grueling, harsh, heavylaborious, murderous, no picnic, onerous, painful, punishing, rigorous, rough, severe, strenuous, taxing, tiring, toilsome, tough, troublesome, trying, uphill. I can't say it any clearer than that!!

Tomorrow, I'll put the carb back together and HOPEFULLY can get this thing moving!!!
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