Hey guys,
Need some help with a new issue. Last Friday I was off work and it was a beautiful 70 degree sunny day. So instead of tending the multiple tasks needed on the farm I decided a nice second drive of the 2021 season with my 1941 Chevy 1 1/2 ton 4x4 GI with a 1954 235 was in order. Got to keep your priorities in order, right?
So the truck performed along approximately 50 miles of seamlessly good performance over many conditions including both highway (with me screaming along at 40 mph or so) and super curvy old roads with frequent steep sections both up hill and down. On the way home I stopped to get some items at my favorite old style auto parts store. Perhaps I was at the store for about 20 minutes, and the truck starts fine considering that I was starting a pretty hot engine. The truck seems completely fine at this point. I pull out of the store and drive up the road to the town square (an approximate 6 percent incline). I sit at the traffic light waiting to take a left, and proceed when I get a gap in traffic. Right as I was crossing over the oncoming lanes, the truck starts acting like it is running out of gas (properly functioning fuel gauge shows better than 3/4 tank as I filled it up on my last drive a week prior). I push in the clutch and feather the gas to try to keep it from completely stalling. Fortunately some fancy foot work kept the engine running and it recovered and on I went, driving approximately 10 more event free miles, I start to ascend my very long and steep driveway (20 percent grade average). Here is where it got hairy. About 100 feet into the climb, the truck in second gear (1:6.77 gears in this old gal) starts to act like it is running out of gas again and this time it does stall. I put the truck in neutral apply the parking brake, and go to hit the foot starter. The truck restarts fine. I sit there contemplating what just occurred and proceed to do a first gear restart on a steep hill feathering the clutch while simultaneously releasing the parking brake (yeah, fun right?). The process goes better than expected and I proceed driving. In about 150 feet, she stalls again. Again I repeat the previously mentioned process and again it starts back up just fine. She stalled 4 times climbing that darn steep section of my driveway, but each time it started fairly easily considering it is a hot engine!!! I finally make it up the incline and the truck drives fine the rest of the time. I let the truck idle when I got home and it ran fine when not under heavy load.
The first occurrence symptom reminded me of a fuel pump that is dying, but in past experiences with crapping out mechanical fuel pumps, they don't recover at all. Yeah I know, it's never the fuel system. I am including a video of the fuel pump at idle. It looks like it is pumping okay to me, what do you all think? I also thought of a poorly venting gas cap, but unfortunately I thought of it too late (the next day) so I squandered my investigation opportunity. When checking the fuel cap about 18 hours after driving, there was no vacuum pressure in the tank. I have had history with venting fuel caps not venting properly on this truck but felt the current one (that has been on the tank for a few years) has been working okay.
So what in the devil happened? What should I check first? The fuel pump was NOS but rebuilt with modern materials about 4000 miles/6 years go. The truck has an original AC T-2 type fuel filter that has been converted to a large paper filter (GM854425 used on old saddle tanked GM trucks). I annually bleed off water from the fuel bowl but have not replaced the filter since putting the truck together 6 years ago. Tank was professionally cleaned and lined at time of build. My thoughts are to replace the fuel filter, and conduct a volume flow check on the output side of the fuel pump. I don't have access to a pressure gauge.
Sorry for the verbose question, but hopefully; all of the "who, where, what and when's" should be addressed. I appreciate your insights.
Edit, evidently stovebolt doesn't support .MOV video files, will send as a youtube link in a bit.
Last edited by Paul_WNC; 03/28/2021 3:31 PM.
