Fuel starvation?

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ANDREW269
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  • 2 POSTS
I have a 1988 S10 pickup, 2wd, approx 160k miles, 4cyl. The truck has never given any problems in the past few years, then the other day as I was headed to work, I was on empty, so I stopped and filled the tank with gas, and as I continued on my way to work about 5 miles down the road the engine stumbled and stalled and I was unable to restart it. I called for a lift the rest of the way to work and decided to check it out after work. Long story short, I wound up towing the truck home. I have replaced the fuel filter and ignition module (the fuel pump was replaced a few years ago). I thought the fuel pump might be bad, so I disconnected the fuel line after the filter, connected a hose to it, and ran the other end into a gas can. I used the relay bypass to energize the pump, and proceeded to pump out the gas. The fuel pump is working. What I am wondering, though, is, can the pump still be working but not delivering enough gas to the engine? I re-installed the fuel filter and poured about a tablespoon of gas into the TBI and the engine started but ran real poorly, surging, and finally stalled again. Should I drain the tank and replace the pump, or look somewhere else first? Thanks.
Oct 3, 2007 at 10:59 AM
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BMRFIXIT
  • ✓Experienced Mechanic
  • 19,053 POSTS
[quote:911c9194d3="Andrew269"]I have a 1988 S10 pickup, 2wd, approx 160k miles, 4cyl. The truck has never given any problems in the past few years, then the other day as I was headed to work, I was on empty, so I stopped and filled the tank with gas, and as I continued on my way to work about 5 miles down the road the engine stumbled and stalled and I was unable to restart it. I called for a lift the rest of the way to work and decided to check it out after work. Long story short, I wound up towing the truck home. I have replaced the fuel filter and ignition module (the fuel pump was replaced a few years ago). I thought the fuel pump might be bad, so I disconnected the fuel line after the filter, connected a hose to it, and ran the other end into a gas can. I used the relay bypass to energize the pump, and proceeded to pump out the gas. The fuel pump is working. What I am wondering, though, is, can the pump still be working but not delivering enough gas to the engine? I re-installed the fuel filter and poured about a tablespoon of gas into the TBI and the engine started but ran real poorly, surging, and finally stalled again. Should I drain the tank and replace the pump, or look somewhere else first? Thanks.[/quote:911c9194d3]


fuel pump may be working but it has to provied the fuel injectors with pressure and volume
if one missing u have no start
check the fuel pressure you may need that pump!

by u putting gas in the TBI and engine starting we know u have spark and the problem is fuel
check the injectors if the are working
and TPS
good luck
let us know
Oct 3, 2007 at 11:44 AM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
Could be the pump-to nail it you have to check the actual fuel pressure- if its okay-start it up and feather it-when it gets good and going remove the fuel pump relay if it dies out-inspect/test the oil sending unit. This is the one that powers the pump after the initial start.
Oct 3, 2007 at 11:44 AM
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ANDREW269
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  • 2 POSTS
Well, it wasn't the pump. I did the fuel pressure test, and got surges of pressure, so I thought for sure the pump was failing. I bought a new pump and strainer, and proceeded to drop the tank and replace them. When I got the pump/sender assembly out of the tank and started to remove the pump, I noticed the real problem. The little 2" rubber hose connecting the pump to the pipe was split, so the line was never fully pressurizing. I imagine that once the pressure started to build, the split hose would open up and the pressure would fall, resulting in the pressure surging observed on the test. Of course, I went ahead and replaced the pump and strainer anyway, since I was already that far into it. Problem solved.
Oct 29, 2007 at 11:06 AM
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