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Old Jul 9, 2019 | 09:39 PM
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Default LS3 Power surge

Hello all


I'm not sure where to put this so I'm going to put it in 2 places,


I installed a crate LS 3 430 HP connect and Cruise into my 1986 C 10, runs great plenty of power runs smooth and decent mileage. Typically you think great as I did until the other day I took it over to the coast, its a 35 mile trip with hard curves inclines and declines, after about 25 miles of this drive, decreasing the accelerator as I enter the turn and advancing the accelerator out of the turns I noticed my power was reduced and began surging as I tried to accelerate out of the turns. There were no other symptoms other than the power surge and sluggish decrease in power. It continued running this way for the final 10 miles, got to my friends house turned it off it sat for about 20 minutes I started it back up it ran perfectly fine, we went around town everything was back to normal until left. Back on the windy drive where again about 25 miles decreasing the accelerator in and advancing the accelerator out of the turns it again lost power became sluggish and began surging in and out of power upon acceleration, got home shut it off for a couple minutes started back up and its been running great with no power loss or power surges as I normally drive around town, the only difference is that I'm not on that road working the accelerator in and out of the turns? does anyone have an idea what this could be?

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Old Jul 9, 2019 | 09:55 PM
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What do you have for a fuel tank? Is it possible that it's uncovering the pickup and sucking air?
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Old Jul 12, 2019 | 11:11 AM
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Originally Posted by rodwood
…..I installed a crate LS 3 430 HP connect and Cruise into my 1986 C 10......
Do you have the stock (OEM) gas tank and pump, or do you have a baffled gas tank and 255lb pump for a fuel-injected engine?

KW
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Old Jul 12, 2019 | 09:50 PM
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I did reinstall the OE tank with a Holley eliminator fuel pump, I did know of the inherent problems with doing this unbaffled setup but was convinced that keeping the tank over 1/4 full I wouldn't see any symptoms. I have experienced some fuel starvation when going down my sloped drive although it only happens when I'm Below 1/8 tank and the symptom is a clear stall and the engine dies, once I level off it picks up again runs fine, there is no power loss other than the engine dyeing and there was no surge. On the trip I'm talking of the tank was over 3/4 full no chance for the pickup to expose ? I did experienced power loss and clear surging. with this much fuel in the tank could it in your opinions still starve for fuel or have the pick up exposed?
thanks for all your help,,






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Old Jul 17, 2019 | 12:25 AM
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Fuel tank sloshing would be my first guess too. You can test by filling the tank and try driving in circles left and right. Then try again later with less fuel in the tank. Figure out if, say one direction left/right, can recreate the problem repeatably. My Bonneville SSEi used to do this stock around right-hand corners if there was less than half a tank in it. If it is not fuel, perhaps you have a wiring issue somewhere, maybe even something melting/grounding against the headers.
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