eng. missing under coast condition?
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eng. missing under coast condition?
i have yet another question regarding my 85 dually i picked up. it seems that when you are doing about 55 or so and let off the fuel i am getting what appears to be a bad engine miss. any ideas?
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no it hasnt stalled out on me at idle, and i am pretty sure it is the motor missing because it does it sparadically. the whole truck bucks pretty bad when it does it. when you give it fuel again after it starts doing it,it goes away
Lead Driver
Joined: Jan 2005
Posts: 7,782
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From: Huntington Indiana
Going back to basics.. When was the last fuel filter change? have you changed the fuel return lines between the injectors? Wondering if some air is getting in when you let off on the power band. I also found on my 93 a bad fuel line from the tank along the frame. gave me real fits to find it. It ran rough like yours.
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i havent really noticed to much smoke, it does smoke a little whe you get on the throttle. the fuel filter looks new, i havent noticed the injector caps leaking any fuel but that doest mean they arent leaking fuel i guess. it doest have any cold start issues.
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Lead Driver
Joined: Nov 2003
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From: Campbell River, B.C.
One more question, does the truck try to stall if you rev the engine up to 1500-2000 RPM and then release the accelerator (at standstill in neutral)?
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Lead Driver
Joined: Nov 2003
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From: Campbell River, B.C.
This is one I haven't heard before. A misfire should cause a smoke puff that lines up with the thump in the engine (or at least SHOULD). I would check the drive shaft just to be sure. A loose U joint can cause some strange symptoms (tranny in neutral).
Posting Guru
Joined: Sep 2007
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From: Las vegas
Sounds like a bad ring in pinion to me. One of the teeth may be damaged on the back side when you let off the go pedal the oposit side of the ring and pinion ride on each other the bucking may be the bad tooth comming around.
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a chipped tooth in the ring and pinion would almost definately make some gear noise wouldnt it? a loose u joint would result in drive train clunk wouldnt it? i am getting neither of these. i am pretty sure it is the motor missing. its acting just like a gasser does when it is loading up with fuel. the truck is bucking pretty bad, and it doesnt make any clunking noise when it does it, which is sparadic.