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5.9L engine idle problem

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  #21  
Old 01-10-2015 | 10:39 PM
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Originally Posted by Chad12Cummins
I hadn't even thought about the MAP sensor. Where is it located exactly?
It's hanging on the front of the throttle body. I'll be surprised if it's at fault. Not "woulda bet my house on it" surprised, but still surprised. It's one of those parts that gets replaced by guess and by golly fairly often, to no benefit except that of the parts store.
 
  #22  
Old 01-10-2015 | 10:55 PM
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The little rubber elbow that feeds can be problematic though, but, that's pretty rare.
 
  #23  
Old 01-10-2015 | 11:27 PM
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[QUOTE=UnregisteredUser;3219502]It's hanging on the front of the throttle body. I'll be surprised if it's at fault. Not "woulda bet my house on it" surprised, but still surprised. It's one of those parts that gets replaced by guess and by golly fairly often, to no benefit except that of the parts store.[/QUOTE

Ok. Haha, guess that's why I didn't see it on the intake. We'll start by unplugging the 02 sensor and see what happens. I'll post back with the results.
 
  #24  
Old 01-12-2015 | 10:23 PM
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Originally Posted by UnregisteredUser
If it ran fine like that in the past, then it's likely the sensor gone kaput. Try unplugging it to force the PCM to stay in open loop, and take a drive. You'll get a check engine light and codes due to the unplugged sensor. If the symptoms don't appear with the O2 sensor uplugged, it's time for a new sensor.

It was suggested above that you might try cleaning the thing, and it might sometimes work for a while, but it's much better to replace the sensor if it's failing. The risk is that most folks would be happy to call it a win if the symptoms mostly disappear, but if the engine is still running lean it'll accelerate the wear of the expensive parts in the combustion chambers. It'd actually be better, if the part has failed, to just leave it unplugged until you can get another installed. Running a tad rich, with no catalytic converter to be harmed by it, isn't really a problem.
Ok.... We unplugged the 02 sensor and the truck isn't cutting out anymore. We're getting a new one to put on and see where we're at.
 
  #25  
Old 01-12-2015 | 10:42 PM
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Originally Posted by Hippiej7666
1999 Dodge Ram 1500 Laramie 4X4 ext cab 5.9L

still tryin to figure out how to put it in my signature.
also....dont know if this has anything to do with it but i do hear a very very slight and quiet sucking sound when it idles rough...and i noticed for the 1st time yesterday that it will randomly rev upto about 2grand rpm when idling....did it once in about 15 minutes....aside from that occasionally i'll barely touch the peddle and it will go upto about 2000rpm and seems like it sticks there for a second before it comes back down....now it doesn't always do this and i'm just mentioning it incase its connected to the problem.
That sounds like an erratic Idle air controller,or IAC. Check and make sure it's not loose on throttle body.
 
  #26  
Old 01-12-2015 | 11:46 PM
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Originally Posted by Chad12Cummins
Ok.... We unplugged the 02 sensor and the truck isn't cutting out anymore. We're getting a new one to put on and see where we're at.
There ya go. As has been said several thousand times, go with a dealer part if you can, and if not prefer Denso, then NTK, but stay away from Bosch. (The Bosch parts aren't bad, per se, but our PCM's don't like them.) You're going to see a world of difference with the new one in there. More power, better mileage, and an end to the painful burn and itch of hemorrhoidal tissue. Or at least one less pain in your ***.
 
  #27  
Old 01-13-2015 | 12:12 PM
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Originally Posted by UnregisteredUser
There ya go. As has been said several thousand times, go with a dealer part if you can, and if not prefer Denso, then NTK, but stay away from Bosch. (The Bosch parts aren't bad, per se, but our PCM's don't like them.) You're going to see a world of difference with the new one in there. More power, better mileage, and an end to the painful burn and itch of hemorrhoidal tissue. Or at least one less pain in your ***.
Thanks. You've been a huge help and it's much appreciated. If we have anymore trouble I'll post back.
 
  #28  
Old 01-17-2015 | 12:41 AM
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It's nice to see people follow through with their post. It frustrating to read 3 or 4 pages to see there was nothing posted saying what fixed their problem. This is the first in five post I have read that did. I have an 02 1500 4x4 with a 5.9 and automatic . I know 02 is a 3rd Gen but I would think 2nd Gen people would know more about the 5.9. In the last two days my truck has misfired 3 times and it seems to have a random but constant hesitation. It's does it during acceleration and cruising speeds in most gears. Have not driven it in first to see. But second, drive and overdrive. It seems to idle smooth and no noticeable lack of power. The rpms don't seem to fluctuate. There is no check engine light on. I'm just looking for some advise. I have not changed plugs or wires. I was trying to see if it could be bad gas or other options there are. I would think with the misfires my check engine light would come on. I live an hour and a half from an auto zone or checkers. So if I need to read the codes I'll have to take it to the mechanics. I have done the key trick and it flashes ------ then done. Thanks
 
  #29  
Old 01-17-2015 | 10:00 AM
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Have you checked your plenum? When is the last time plugs/wires/etc were changed? How does it run when you stick your foot into it? (hard acceleration)
 
  #30  
Old 02-13-2018 | 12:59 PM
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Originally Posted by Hippiej7666
Hello everyone,
So here's my problem, i'm taking my truck to a mechanic in afew days to try and get this fixed but from searches on the internet i've found alot of people with this happening and in every case it seems they've done something different to fix it or couldn't get it fixed and alot of them complained about the end cost after a mechanic went through and replaced part after part.....so here's the problem, i bought my 99 ram 1500 5.9L 4X4 recently and drove it home with no problems (200miles) a day or two later i had it running at idle and all of a sudden my idle drops to about 5 or 600rpm and it sounds really rough like it struggling to stay running.....i reved it up once or twice and it went back to normal idle...around 900rpm i think, so i didn't think much of it.....well later on i was driving and came to a stop and while sitting there idling it suddenly dropped down to the 5-600rpm ranged and was idling rough, engine shaking ect and the light turned green...now i went to take off and the engine was stuttering and cutting out and i started to slow back down to almost a standstill, at the same time i heard popping or backfiring into the air cleaner i believe...i stepped on the peddle to the floor and it cut out for a second then the engine roared to life and i got upto speed (35mph)....now the CEL has come on and i've read the codes and it says its running rich and the O2 sensors are bad, we cleared teh code and i continued driving it....it still does it completely randomly and usually does cause the CEL to come on again.......now i went through and replaced plugs, wires, cap, and rotor....exhaust seems to have good pressure comming out the pipe but it still seems to do this...its completely random....does it when its warmed up or when its cold.....might do it once in 40 miles of driving or several times...there's no pattern........i should also mention it seems like its getting really poor mpg....i havn't done the math to see exactly what my mpg is but i can put half a tank in it and drive it alittle around town and go home and i'm almost back on E again.......... dont know if this is part of the problem but i've noticed that to hit hiway speeds (70mph) i seems like i gotta have the peddle to the floor........anyway, i just want some idea of what it might be so that i can point the mechanic in the right direction without costing me an arm and a leg in parts tryin to fix this......mechanic looked at it once and because it didn't throw a code and when he test drove it afew miles it didn't do it he thought it was fixed........PLZ HELP!....ty.
You basically listed my situation with my 98 durango 4x4 with the same engine. I have read a ton of posts and have replaced/reset/tuned up, etc.
iac, tps, map, cap, rotor, wires, plugs, clean TB, scanned o2 sensors, battery,
taken it to mechanics. It is totally baffling that nothing seems to make this problem go away. It gets better when I reset the computer. It slowly returns to irratic idle and dieing at stop signs. I have owned this truck since 1998 and it ran great until the crank sensor failed. After replacing that, it ran fine for a few months and then this un fixable idle problem showed up. I answer you in hopes that if you ever crack this mytery, I will maybe hear through you or a response to this thread.
 


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