I have been battling a loss of fuel problem..."I Think!" and have been throwing parts at it for some time and had no luck yet. The truck runs great for a while and then acts like it's running out of gas. If I keep pumping the gas peddle it sometimes stumbles a while and then smooths out and runs fine again. One time while it was stumbling I pulled the air filter and one of the TBI injectors were hissing air, no cone shaped fuel spray. Replaced both injectors and the problem still exists. I have replaced the fuel filter and the cap and rotor. Someone suggested that I try to recycle the ignition several times and then try starting it when it stalls and strangely enough that worked, after cranking away forever with no luck I tried the recycling trick and after three recycles it fired right up and has ran fine since. However, I know it will raise it's ugly head again. I think I only have the fuel regulator and fuel pump left to replace but hate the thought of pulling the tank to find yet again it stuttering. I am still not sure it's not an electronic problem but I'm at the end of my wits and hope I can get some help from this forum. Thanks in advance! Paul K.
Like it's running out of gas?
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Sounds like fuel pump. Dont drop the tank, tilt the bed.
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sorry I thought I was in a Chevy Truck Forum | GMC Truck Forum - GmFullsize.com > General > Maintenance thread. My Bad. Didn't know about the Space Shuttle thread.
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Since duallys were made for a number of years through many different body styles with many different engine types I thought it to be important that you specify which year and motor your truck has.
Sarcasm. Its whats for dinner.
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Have a helper, or two, lift the cap off.
Have same helper, or two, lift one side of bed.
Place MORE THAN ONE board under bed.
Change fuel pump.
Feed helper(s)
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Before you replace the pump, check the fuel pressure. Make sure you replace the fuel filter too. A pump can't do it's job with a clogged filter.
Guardrail
Guardrail
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"... I have replaced the fuel filter and the cap and rotor. ..."
Looks like he already did. Pump could also be putting out correct pressure, but have a bad check valve. This would explain why priming the system helped in starting.
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Assuming that it is the fuel pump that needs to be replaced. OP was looking for ideas - not a how-to on how to replace fuel pump.Motor choice dictates bed size? I never knew...
Guardrail
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the check valve could be the problem, but wouldn't be what's causing his truck to stall while running. the check valve keeps the fuel line primed while the truck and pump isn't running.
good luck with the pump.
What is still unclear to me is that only one (passenger side) injector was spitting air not both. I'm just thinking what could be the separation point could be the failure. However, the above issue could be only an action in a long chain of events hitting that injector first. I appreciate all the positive responses keep then coming. Thanks! Paul K. BTW, it hasn't failed once since I did the ignition recycle trick but I know it's coming.
After a lot of time and money throwing parts at this problem I think I have found the issue, not the fix.
I found that the ECM located behind the glove box was overheating. When pulled out it was hotter than what you wanted to hold in your hand. I removed the ECM placed into my freezer waited 30 minutes and reinstalled it and the truck ran great until it heated back up. I then duck taped it on the AC vent for cooling and the truck never hiccuped once.
Now with my new knowledge I purchased a rebuilt ECM from local parts store but to my surprise it didn't come with new Eproms. I asked the counter person: How do I know if the ECM isn't the problem in the first place? His reply was that the Eproms are never the problem.
With love in my hart I swapped the Eproms and installed the "new" rebuilt ECM and Guess What? Yep! Same freaking thing, as soon as the ECM got hot, she started running bad.
A friend said that the GM's with 454s were a major problem involving the overheating ECM and they had an ECM relocation kit that was used to solve the problem.
I am at the point where I'm going to mount two 12vcd computer fans to the ECM and see what happens......unless someone on the forum has a better idea? Thanks Paul K.
I found that the ECM located behind the glove box was overheating. When pulled out it was hotter than what you wanted to hold in your hand. I removed the ECM placed into my freezer waited 30 minutes and reinstalled it and the truck ran great until it heated back up. I then duck taped it on the AC vent for cooling and the truck never hiccuped once.
Now with my new knowledge I purchased a rebuilt ECM from local parts store but to my surprise it didn't come with new Eproms. I asked the counter person: How do I know if the ECM isn't the problem in the first place? His reply was that the Eproms are never the problem.
With love in my hart I swapped the Eproms and installed the "new" rebuilt ECM and Guess What? Yep! Same freaking thing, as soon as the ECM got hot, she started running bad.
A friend said that the GM's with 454s were a major problem involving the overheating ECM and they had an ECM relocation kit that was used to solve the problem.
I am at the point where I'm going to mount two 12vcd computer fans to the ECM and see what happens......unless someone on the forum has a better idea? Thanks Paul K.
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Check for any grounded positive wires, any bad grounds, alternator voltage, voltage at the ecm. If the ecm is getting hot even after a swap, to me that says electrical issue.
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Could you be a little more specific. You say "Check for any grounded positive wires" seems if there were a ground positive 12vcd wire it would blow a fuse or burn the wire. What is "alternator voltage, voltage at the ecm"?
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Generally speaking, if a wire is grounded, it blows the fuse. I have personally fixed many different vehicles of all sizes where it didn't blow the fuse. For alternator voltage, with the truck running, check the charging voltage the alternator is putting out. For the ecm voltage, with truck running, back probe the harness to verify everything had the appropriate voltage or ground. Or, if you aren't comfortable with it, have a friend help. I've seen a couple ecm's get warm, but not hot. If it get hot, it's a definite problem. How old is the battery? What do the connections look like? Nice and clean or corroded?
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