COCHEV
1/2 ton status
Yes! Then I can get rid of another mile of vac line...
Maybe I'll come visit your garage this weekend
CK5
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2 fuel pumps?
- Thread starter COCHEV
- Start date
Yes! Then I can get rid of another mile of vac line...
Maybe I'll come visit your garage this weekend
COCHEV
1/2 ton status
So I'll have to see if this thing sputters out half way to work on the mechanical pump.
Better hope that the mechanical pump doesn't have a ruptured diaphram,because the electric pump will pump gas into the crank case thru the torn diaphram...and goodbye bearings,if you dont change the oil soon enough...
....seen more than one nice running engine ruined by a bad fuel pump diaphram...gas washes the oil off all the moving parts and loosens up sludge,allowing it to be pumped thru all the oil passages in the engine...it's like running it with grinding compound in the oil...
....seen more than one nice running engine ruined by a bad fuel pump diaphram...gas washes the oil off all the moving parts and loosens up sludge,allowing it to be pumped thru all the oil passages in the engine...it's like running it with grinding compound in the oil...
COCHEV
1/2 ton status
Better hope that the mechanical pump doesn't have a ruptured diaphram,because the electric pump will pump gas into the crank case thru the torn diaphram...and goodbye bearings,if you dont change the oil soon enough...
Well that would suck a whole lot. It runs off the mechanical pump great for about say 15-20 min. Of driving, then starts to sputter and die unless I kick on the electric pump. Its weird. The first 15 min or so on the mechanical pump it runs strong all the way to WOT. I think I might be getting some kind of vapor lock, but its not even close to hot here.
COCHEV
1/2 ton status
So, no luck. The first part of my commute is about 5 miles of stoplight traffic, then its on the freeway for a few miles that's on a decent grade. This is where it starts to cut out. Today it almost didn't recover when I kicked on the electric pump.
Wonder if my float is out of adjustment and the grade is sucking the bowl dry.
Wonder if my float is out of adjustment and the grade is sucking the bowl dry.
1BEATK5
1/2 ton status
Did you rebuild that carb?
COCHEV
1/2 ton status
No, that's next. I'll do that in conjunction with a fuel pump and see if I can't cut the cord on the damn noisy carter out back once and for all.
1BEATK5
1/2 ton status
Hoe long does it take under heavy throttle to cut out?
COCHEV
1/2 ton status
Doesn't even have to be heavy throttle. Its more of a time thing. Seems like about 10-15 min. Did it today on the way home cause I forgot to flip the switch on the pump. Started cutting out at cruise rpm at about 40 mph...
1BEATK5
1/2 ton status
Seems like a plugged sock might be your issue. It's amazing how long they will run on just the fuel in the line from the tank. Had that on the k5.
Hope that not it of corse.
Hope that not it of corse.
COCHEV
1/2 ton status
Wouldn't that choke out my electric pump too?
1BEATK5
1/2 ton status
I was thinking it would have better sucking power
COCHEV
1/2 ton status
Well I sure hope I get to drop the 40 gal tank! I mean, after breaking all my collecter bolts and doing the heater core last week, I was looking to kick it up a notch.
1BEATK5
1/2 ton status
I would rather do the tank then the heater core. But yeah buddy.
COCHEV
1/2 ton status
Update...ish. Rebuilt the carb yesterday. Several of the idle tubes had fallen out of the air horn and were just laying in their holes. I fixed that. Also bought a new float and set that to spec and put her back together. Also installed a new fuel pump.
So...it runs great...until I go up a long grade. Then it runs out of gas and starts to sputter out until I kick on the electric pump. Annoying.
Looks like there is either too much resistance for the mechanical pump to pull fuel through the Carter pump under load. Or, like 1beat says, the sock around the pickup in the tank is clogged up just enough to bog down the mechanical pump but not the electric?
So...it runs great...until I go up a long grade. Then it runs out of gas and starts to sputter out until I kick on the electric pump. Annoying.
Looks like there is either too much resistance for the mechanical pump to pull fuel through the Carter pump under load. Or, like 1beat says, the sock around the pickup in the tank is clogged up just enough to bog down the mechanical pump but not the electric?
COCHEV
1/2 ton status
I guess I could bipass the electric pump to test the one theory. But I don't know where to test it out close by in case that fails. Don't really want to stall out on the freeway
I've had a few vehicles exhibit symptoms like yours,and replacing the fuel pump and filter did no good...one in particular would run great,until I attempted to climb up a long grade on a highway,I made it about 3/4 of the way up and then it would start bucking and stalling,eventually would die and not want to restart ,unless it sat there a few minutes...
What finally was discovered was a section of rubber fuel line that looked like an inchworm about a foot long,hear the rear tire that joined 2 steel fuel line sections together,must have become soft and the inner liner would collapse when the pump demanded more fuel...replacing it cured the trouble,only took me about 3 months to finally find what caused it,after doing endless work un-nessasarily...another vehicle had a rust pinhole on the top side of a steel fuel line that let the fuel pump draw air in,instead of gas from the tank...I never saw any leak or smelled gas either,till one hot summer day when I was parked on a hill and then I smelled gas,and a close inspection revealed the rusted section of line..I replaced it with copper and never had it bog down or stall again...
I've also seen a few engines that had the lobe on the cam running the fuel pump wear down enough so as to not let the pump get enough "stroke" to pump enough fuel too--the push rod can wear down also and do the same thing..
What finally was discovered was a section of rubber fuel line that looked like an inchworm about a foot long,hear the rear tire that joined 2 steel fuel line sections together,must have become soft and the inner liner would collapse when the pump demanded more fuel...replacing it cured the trouble,only took me about 3 months to finally find what caused it,after doing endless work un-nessasarily...another vehicle had a rust pinhole on the top side of a steel fuel line that let the fuel pump draw air in,instead of gas from the tank...I never saw any leak or smelled gas either,till one hot summer day when I was parked on a hill and then I smelled gas,and a close inspection revealed the rusted section of line..I replaced it with copper and never had it bog down or stall again...
I've also seen a few engines that had the lobe on the cam running the fuel pump wear down enough so as to not let the pump get enough "stroke" to pump enough fuel too--the push rod can wear down also and do the same thing..
COCHEV
1/2 ton status
So, diesel4me you might be right with the soft fuel line...
So I wiggled myself under the beast enough to disconnect both ends of the fuel pump so I could blow through it. Which I could, but with some resistance. I also noticed the rubber line on either side of the pump seemed pretty damn soft.
So I bought some new fuel line and bypassed the pump and went out for a little spin up some hills in the nicer part of town (didn't want to get stuck on the freeway) after several passes in second gear at decent rpms she didn't bog once.
So maybe with that old soft fuel line and the mild resistance of the pump, the mechanical pump was sucking the fuel line closed?
Let's hope. It has to pass another test hill before I'm sold it worked. The old fuel lines and hose clamps are in the glove box in case I need to hook the electric pump back up on the road side
So I wiggled myself under the beast enough to disconnect both ends of the fuel pump so I could blow through it. Which I could, but with some resistance. I also noticed the rubber line on either side of the pump seemed pretty damn soft.
So I bought some new fuel line and bypassed the pump and went out for a little spin up some hills in the nicer part of town (didn't want to get stuck on the freeway) after several passes in second gear at decent rpms she didn't bog once.
So maybe with that old soft fuel line and the mild resistance of the pump, the mechanical pump was sucking the fuel line closed?
Let's hope. It has to pass another test hill before I'm sold it worked. The old fuel lines and hose clamps are in the glove box in case I need to hook the electric pump back up on the road side
COCHEV
1/2 ton status
Well, I think I fixed it. Took her out on the highway and up some grades with no issues this time. I'm still going to leave the electric pump mounted for the weak just to make sure. If there are no issues after a week of commuting, its going in the dumpster
Hope you cured it,it can suck pinning things like this down,sometimes you find more than one possible cause and can never say for sure "that" was what was causing it..
I'd keep the electric pump just in case,or for a spare...
I use one around the yard and garage to suck gas out of my lawn tractors or cars when I need fuel for something....my diesel pickup has an electric pump I put near the tank,to use as booster to the mechanical pump on the engine..I can shut off the electric one and it wont kill the engine,but you can hear and feel the difference in how it runs with it off..
I'd keep the electric pump just in case,or for a spare...
I use one around the yard and garage to suck gas out of my lawn tractors or cars when I need fuel for something....my diesel pickup has an electric pump I put near the tank,to use as booster to the mechanical pump on the engine..I can shut off the electric one and it wont kill the engine,but you can hear and feel the difference in how it runs with it off..
