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1LowToy · 02-19-2011, 01:31 PM

Proper tuning will increase fuel mileage of course. The carburator more than likely has an idle solinoid which when is in the run position (key on) is your curb idle position. Key off the solinoid retracts to a very low idle position, usually 75 to 100 rpms less than the curb idle. This it what stops the dieseling after shut down provided the carburator is not running too rich at idle. If you turn the key on and ever so gently touch the throttle you can feel it engauge. After proper tuning and the idle solinoid is adjusted properly the dieseling should stop. If not you have carbon buildup on tops of the pistons and combustion chambers. The carbon is glowing and igniting the fuel coming in from the carburator.

02-19-2011, 01:31 PM	#6
1LowToy Registered User Join Date: Nov 2009 Location: Sonora California Posts: 860	Re: Hard shut off on 4.1l engine Proper tuning will increase fuel mileage of course. The carburator more than likely has an idle solinoid which when is in the run position (key on) is your curb idle position. Key off the solinoid retracts to a very low idle position, usually 75 to 100 rpms less than the curb idle. This it what stops the dieseling after shut down provided the carburator is not running too rich at idle. If you turn the key on and ever so gently touch the throttle you can feel it engauge. After proper tuning and the idle solinoid is adjusted properly the dieseling should stop. If not you have carbon buildup on tops of the pistons and combustion chambers. The carbon is glowing and igniting the fuel coming in from the carburator.