I have a 03 7.3 with php 6 position, cold air, and 4" ehaust. Its happened twice in the last three days. First thing in the morning go to start the truck and it idles really rough and has no power for the first couple miles withno check engine lights. Then it clears up and runs great the rest of the day. Any help would be great!!! Thanks :thumbsup:
Need help!!! Rough idle in the AM!!!
- Thread starter jbro78
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Ron's Power Stroke
Member
i assume it has been cold mornings?? been down near 40's here..30's tonight...if thats the case and if you also have white smoke it could be your glow plug's.. the gutless feeling is the warm up valve (EBPV) is closed till the motor is warmed up..that's when it opens and the truck starts running stronger,,,,
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I am thinking its the EBPV. I bet if you listen with the windows open you will hear that your exhaust sounds very different between when this is happening and how it sounds once it running fine. If you do not know what it does do a google search on it and you will get all you need. Basically think of what an exhaust brake in the closed position would do to power.
IMO its a good thing as hopefully it will keep you from stomping on the go pedal when its cold. Want to hurt one of these engines jump on it before the oil is up to full temp. The cold it is and the sooner you jump on it the more chance you have of hurting it. Drive your truck easy till its fully warm.
IMO its a good thing as hopefully it will keep you from stomping on the go pedal when its cold. Want to hurt one of these engines jump on it before the oil is up to full temp. The cold it is and the sooner you jump on it the more chance you have of hurting it. Drive your truck easy till its fully warm.
how many miles are on the engine/injectors?
rough running (or low power) when cold, but runs fine when warm...is indicative of high(er) mileage injector wear at the poppet valve.
this valve seals the HPOil at the injector...and @ 200k miles is about the average for these valves to wear enough to not seal properly...nor allow the proper flow of oil into the injector..WHEN the oil is cold/thick.
here's a link with more info:
http://www.swampsdiesel.com/files/7.3LInjectorDiagnostic.pdf
rough running (or low power) when cold, but runs fine when warm...is indicative of high(er) mileage injector wear at the poppet valve.
this valve seals the HPOil at the injector...and @ 200k miles is about the average for these valves to wear enough to not seal properly...nor allow the proper flow of oil into the injector..WHEN the oil is cold/thick.
here's a link with more info:
http://www.swampsdiesel.com/files/7.3LInjectorDiagnostic.pdf
you don't need to do anything.. it's normal operation.
well, maybe let the truck warm up a couple of minutes..
I'm normally not a fan of warming up, if the oil pressure is up, it's hitting on all 8, drive it.
but I pulled out in front of a garbage truck last year, and my EBPV decided to close at the same time.. and I damn near ended up on the forks of the truck...
maybe gut the thing?
This problem is NOT normal!!! This makes my second 7.3 and I have never had this problem!! Its only done it twice since Saturday morning. Its hard to fix something if it wont keep messing up. I will just clean the ebpv and drive it till it happens again.
Stroker#66
New member
Possibly a problem with the fuel pumP on the frame rail
Arisley
Moderator
Even more reason to think it is the problem.
Also check your glow plug system, make sure they are up to snuff.
I had the same thing happen on my OBS. I'm guessing it's injector related. When mine would do it I would unplug the injectors and found when unplugging #2 and #4 there would be no change in the idle but change when I unplugged the other 6. But after it warmed up it would run fine. When you say it runs better does it gradually get better or is it like a flip of a switch running better?
If you have a scanner or software like AutoEnginuity run a buzz test on the injectors. I have learned long ago to take heed to suggestions made by David@ swamps (Golfer).
It only takes literally 30 seconds after its hooked up to run the tests.
You could also take a look at the Exhaust Back Pressure Sensor and tube. They can sometimes become clogged or broken and the EBPV uses the output of that sensor to function. As do some tuners fuel tables. Stock it does for sure. Also effects some transmission shifting. Not sure what or how or if its actually a function of the effect to the fuel table but it does. The tube being rusted out seems common on the older trucks.
It only takes literally 30 seconds after its hooked up to run the tests.
You could also take a look at the Exhaust Back Pressure Sensor and tube. They can sometimes become clogged or broken and the EBPV uses the output of that sensor to function. As do some tuners fuel tables. Stock it does for sure. Also effects some transmission shifting. Not sure what or how or if its actually a function of the effect to the fuel table but it does. The tube being rusted out seems common on the older trucks.
Its like flipping a switch when it gets better. I have already done a buzz test and a cylinder contrubution test and everything come back perfect. Thanks for all the help going to check the exhaust sensor and tube tomorrow. Thats a free check!!! LOL
psdguy95
New member
How many miles on your oil?
If it's running rough I don't think it's from the EBPV being shut. A closed EBPV would cause back pressure and slow the engine down but not cause it to run rough. My OBS did had the same problems and it didn't have a EBPV. I'm thinking it's an injector or injectors that are taking awhile to "wake up". I ended up selling my OBS before digging into the problem.
That is a good point I was assuming by crap he was meaning no power, sluggish, loud, etc. Its hard without a video or some data logs.
If its actually runnning like crap then I agree with Golfer and you. Like I said I tend to trust what he feels the issue is.
If its actually runnning like crap then I agree with Golfer and you. Like I said I tend to trust what he feels the issue is.
