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Rough idle

3K views 24 replies 3 participants last post by  ArcticDriver 
#1 ·
I have a 2003 7.3 with 155,000 miles on her ..
At random times I have a spudder at idle.

These codes have popped up
P1211 , p0478 , P1280 , P0603

I've replaced the icp sensor and pig tail
Replaced the ipr sensor and pig tail
Replaced the ebp sensor and pig tail
Replaced the fuel pump

I've ordered a bypass from dfuser for the ebp sensor and a terminator for the ebpv
So I'll what those do ,

Anyone have any ideas?
 
#3 ·
Do your codes pop up during the sputter?

Does it occur after engine is at operating temp?
 
#4 ·
Sputter only happens after the truck is at temp , hasn't thrown a code in 6 months of driving it at least 3 days a week or more 100 + miles a day
 
#5 ·
OK. So the codes you listed were from 6 months ago and have been cleared and not returned?
 
#8 ·
Davismx,

Which brand Electrical components (CPS, IPR, ICP) did you install? Some after-market electrical components have been known to fail soon after install. Hopefully you swapped out with Motorcraft parts.

Was your reason for swapping out all of these parts an attempt to fix the sputter or did you notice oil in the pigtails ?

The symptoms you describe are kind of vague but don't sound typical of a bad EBPV or EBPS.

How long has it been sputtering? Is it getting worse? Does the engine die? What happens when you depress the accelerator while its sputtering?
 
#9 ·
All Motorcraft replacement parts , started replacing when the codes were popping up and I was finding oil in a few pigtails.. it's been sputtering about 8 months now. Started in the summer it's now winter. It seems worse some days than others but had been pretty consistent... the engine doesn't die. It doesn't get that bad , but as soon as I give each it some throttle the sputtering goes away until it idles back down.... I just bought a rebuild kit for the fuel pressure regulator and the diesel o rings aluminum housing
 
#10 ·
Update
After rebuilding the fuel pressure regulator with going with the mid spring from diesel o rings kit , it's seems to not rumble as bad but still not solved
Seems it will idle at 750 rpms then drop down to 600 rpms and that's when she rumbles and spudders
 
#11 ·
I am not saying the problem continues to be fuel-related but there is no way to say with certainty without a Fuel Pressure Gauge.

This would confirm the fuel pump is functioning correctly and the fuel pick-up screens in the tank are not plugged.

I just rebuilt my fuel bowl and FPR the same as you.
 
#12 ·
I have fuel pressure gauge , it's in cab hooked up to the fuel bowl on the drivers side ..
It's never constant at one psi, it's either at 55 , 60 or 40
Truck doesn't run any different at any psi
 
#13 ·
That is great you have a gauge.
When do you get the 40 readings?
Has the new gold spring in the FPR made any measurable difference at the gauge?
 
#14 ·
The pressure is always random , it's never a regular pressure say when it's cold or hot... the gold spring made a difference over all. Truck is snapier and seems to run smoother while driving .. but didn't help with the idle
 
#15 ·
Your fuel pressure still drops down to 40 psi at random times? Hot or cold. Idle or at high RPM.

But those times do not coincide with the rough idle?

Whats next on your list? New Bosch lift pump? Opening up the tank and cleaning the two small filters or doing the hutch mod?
 
#17 ·
Maybe one of the more experienced guys here on the forum will have some advice.
 
#20 ·
Update problem solved
I didn't end up swapping pedals.. but about 3 months ago my dad suggested doing an engine flush.. well 3 days ago I picked up some amsoil engine flush ran it thru and changed my oil ... Hasn't spuddered since rough idle gone... I waited a few days and I've put over 200 miles on her. So I believe the injector were getting stuck ... rather then pull the injectors and scrub them. Try engine flush
 
#22 · (Edited)
Do you have a Ford capable scanner?

To review your truck sputters when at idle and the RPM will drop to 600 from 750 at the same time it sputters.
It only does this at operating temp and not when the engine is cold.
The fuel pressure will also drop to 40 psi but that pressure drop is not related to the times it sputters.

You have already replaced ICP and pigtail with a Motorcraft ICP.

You have also rebuilt the FPR and replaced the fuel pump. You have not dropped the tank to see if the filters are clogged.

You also changed your oil recently. What viscosity? What are your morning temps where you live?

Two potential areas of concern are the 40-psi fuel pressure at random times (not just under heavy acceleration) and the 750-rpm idle speed at operating temp dropping to 600-rpm randomly (note that factory idle is between 650-675 rpm at operating temp).

Have you removed your DFuser AIC? This device plugs into your accelerator pedal and has a rheostat to dial in the idle speed to your choosing? Probably best to remove that while diagnosing issues with erratic idle speed.

Have you ever checked for vacuum leaks?

Do you live near Denver? I have an AE Scanner. That would help alot with further troubleshooting. Other than unplugging the DFuser and testing for vaccum leaks, you really need a scanner.
 
#23 ·
Update, dropped the truck off at a shop. Shop said injectors 3,7,8 are bad and ebpv is stuck shut.. ordered ebpv delete setup from diesel orings
 
#24 ·
Update
Last weekend I pulled the injectors , cleaned them up and replaced the seals .. seals were a little tore up. Also replaced the glow plugs
At the same time I also deleted the exhaust back pressure valve with a new housing and new pedistool

I've put about 600 miles on it since and no more rough idle

Fuel pressure remained at 53 psi until i used my remote start.. so im looking into that now. It's a crimestopper setup

But a possible solution for a rough idle
Could be new injector seals with a cleaning or delete / rebuild ebpv
 
#25 ·
Thanks for the update.
 
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