6.9 idi cutting off after revving...ideas?
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5th Wheeling
Joined: Sep 2024
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6.9 idi cutting off after revving...ideas?
1986 f350 with 6.9 idi....been sitting for a year or two....hardly any driving. It starts and idles great. But if you give it power, especially rev it up and come off the throttle, it cuts off. Where do I start first? I was given the truck so just getting familiar with it. Thank you for any tips.
Logistics Pro
Joined: Sep 2007
Posts: 3,737
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From: Western Mass
Just to clarify, do you mean you stomp the pedal, then TAKE your foot off, and instead of returning it idle, it dies? Or you do mean you stomp the pedal, KEEP your foot there, it revs up, then dies with your foot still on the pedal?
If its the first, and it does when trying to return to idle, that is an easy fix, governor in the injection pump is sticking. Drain the fuel filter, fill it up with ATF, start truck and let it idle for 30 seconds, then shut off and let it sit overnight. In the morning, start it up and drive it hard. Repeat if symptoms persist. The ATF sitting in the pump will clean up the gunk that is causing it to stick.
If it was dieing with your foot still on the pedal, do either of the fuel filter warning lights come on? You could have a blocked fuel filter, dying lift pump, or blockage somewhere in the fuel line leading to the engine.
If its the first, and it does when trying to return to idle, that is an easy fix, governor in the injection pump is sticking. Drain the fuel filter, fill it up with ATF, start truck and let it idle for 30 seconds, then shut off and let it sit overnight. In the morning, start it up and drive it hard. Repeat if symptoms persist. The ATF sitting in the pump will clean up the gunk that is causing it to stick.
If it was dieing with your foot still on the pedal, do either of the fuel filter warning lights come on? You could have a blocked fuel filter, dying lift pump, or blockage somewhere in the fuel line leading to the engine.
Logistics Pro
Joined: Sep 2007
Posts: 3,737
Likes: 179
From: Western Mass
If you haven't replaced the fuel filter in a while, definitely can replace it. They will however last a long time. My last one was on for over 3 years (forget the miles) and still going strong, got clogged because I accidentally put in some crappy fuel with some sludge in it.
The filters (at least for a 7.3) are rather expensive, upwards of $30, and more locally. My truck has the fuel heater removed and a plug screwed in from the top, makes it real easy. I just use the water drain at the bottom to drain out the whole thing into a can, then top it up from the top through the heater hole. That may not work for your setup.
The filters (at least for a 7.3) are rather expensive, upwards of $30, and more locally. My truck has the fuel heater removed and a plug screwed in from the top, makes it real easy. I just use the water drain at the bottom to drain out the whole thing into a can, then top it up from the top through the heater hole. That may not work for your setup.
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