Engine performance way down
Thread Starter
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Cross-Country
Joined: Nov 2020
Posts: 63
Likes: 1
Engine performance way down
Went from 12s to 4.7 mpg unloaded. No codes! All my numbers look right on but turbo boost looks low 5-20s psi
Sounds normal at idle and if I get on it but light pedal it sounds like a miss every couple of seconds. (Kinda like “brrrrrrrr brrrrrrr brrrrrrr”) Feels slower then normal.
checked cac boots all were tight. Intercooler not cracked, Replaced J pipe to turbo clamp.
Tried all 3 canned tunes on SCT x4 and that didn’t help. IP sensor IPR just replaced right before this started. Wire harness is a month old along with back pressure senso and cleaned tube and turbo cleaned the month before.
Any suggestions ???
Sounds normal at idle and if I get on it but light pedal it sounds like a miss every couple of seconds. (Kinda like “brrrrrrrr brrrrrrr brrrrrrr”) Feels slower then normal.
checked cac boots all were tight. Intercooler not cracked, Replaced J pipe to turbo clamp.
Tried all 3 canned tunes on SCT x4 and that didn’t help. IP sensor IPR just replaced right before this started. Wire harness is a month old along with back pressure senso and cleaned tube and turbo cleaned the month before.
Any suggestions ???
Mountain Pass
Joined: Jan 2021
Posts: 185
Likes: 4
From: Somewhere in the universe
Do you have EGR???
Is your air filter new?
What kind of diesel you fill your truck
Sounds like injectors, could be wrong
Last time you changed fuel filters? Check fuel pump, remove and clean fuel lines, check if one of your fuel lines got smashed and restricts fuel flow
All those sensors you replaced were OEM? I had a cheap china IPR and after 3 days i had to crank it 3 times to get it started
Turbo cleaning was done correctly?
Have NO other idea what it could be if you give me more details i could help you
Is your air filter new?
What kind of diesel you fill your truck
Sounds like injectors, could be wrong
Last time you changed fuel filters? Check fuel pump, remove and clean fuel lines, check if one of your fuel lines got smashed and restricts fuel flow
All those sensors you replaced were OEM? I had a cheap china IPR and after 3 days i had to crank it 3 times to get it started
Turbo cleaning was done correctly?
Have NO other idea what it could be if you give me more details i could help you
Thread Starter
|
Cross-Country
Joined: Nov 2020
Posts: 63
Likes: 1
Do you have EGR???
Is your air filter new?
What kind of diesel you fill your truck
Sounds like injectors, could be wrong
Last time you changed fuel filters? Check fuel pump, remove and clean fuel lines, check if one of your fuel lines got smashed and restricts fuel flow
All those sensors you replaced were OEM? I had a cheap china IPR and after 3 days i had to crank it 3 times to get it started
Turbo cleaning was done correctly?
Have NO other idea what it could be if you give me more details i could help you
Is your air filter new?
What kind of diesel you fill your truck
Sounds like injectors, could be wrong
Last time you changed fuel filters? Check fuel pump, remove and clean fuel lines, check if one of your fuel lines got smashed and restricts fuel flow
All those sensors you replaced were OEM? I had a cheap china IPR and after 3 days i had to crank it 3 times to get it started
Turbo cleaning was done correctly?
Have NO other idea what it could be if you give me more details i could help you
all are OE including IPR but the back pressure sensors and air filter are not. EGR is J pipe style and intake valve is in place and plugged in. Diesel I usually get at Exxon but this last fill up today was at kroger.
Mountain Pass
Joined: Jan 2021
Posts: 185
Likes: 4
From: Somewhere in the universe
What could be:
Injectors
Could be a little bit the aftermarket EBP sensor but difficult
Bad wairing harness interference shields (not quite sure)
HPOP (sounds like its near death, mine before it died did all that brrr and bad throttle response)
Bad branch tube seals, bad stand pipes and dummy plugs, bad ball tube seals, check reasealing them, and so the injector seals
There could be a tiny (very tiny) high pressure oil leak
Injectors
Could be a little bit the aftermarket EBP sensor but difficult
Bad wairing harness interference shields (not quite sure)
HPOP (sounds like its near death, mine before it died did all that brrr and bad throttle response)
Bad branch tube seals, bad stand pipes and dummy plugs, bad ball tube seals, check reasealing them, and so the injector seals
There could be a tiny (very tiny) high pressure oil leak
Thread Starter
|
Cross-Country
Joined: Nov 2020
Posts: 63
Likes: 1
What could be:
Injectors
Could be a little bit the aftermarket EBP sensor but difficult
Bad wairing harness interference shields (not quite sure)
HPOP (sounds like its near death, mine before it died did all that brrr and bad throttle response)
Bad branch tube seals, bad stand pipes and dummy plugs, bad ball tube seals, check reasealing them, and so the injector seals
There could be a tiny (very tiny) high pressure oil leak
Injectors
Could be a little bit the aftermarket EBP sensor but difficult
Bad wairing harness interference shields (not quite sure)
HPOP (sounds like its near death, mine before it died did all that brrr and bad throttle response)
Bad branch tube seals, bad stand pipes and dummy plugs, bad ball tube seals, check reasealing them, and so the injector seals
There could be a tiny (very tiny) high pressure oil leak
Logistics Pro
Joined: Jul 2014
Posts: 4,673
Likes: 531
From: Houston, Texas
You sound like you know what you're doing, and everyone knows I don't; but, I'll throw this out anyway - check your oil level. Maybe you're losing fuel into the crankcase. Are your batteries good? FICM connections in good? And you're getting all your gears, not in 5 gear limp mode? Might as well check that your fuel bowl is filling up quickly, and while it's open do a bubble test. Is your Vref good? Check that vacuum hose coming off your passenger valve cover for cracks or holes.
The low MPG is what puzzles me. It seems like my MPG maybe improved a little whenever I've blown an injector - didn't have any power, but wasn't using as much fuel. And if your low power is due to low fuel pressure, again, you might have better MPG. If you were stuck in a low gear, I'd expect the low MPG, or towing with a stuck turbo. But just driving unloaded with a stuck turbo, I'd expect better MPG than that. It's like you're losing fuel somewhere. Which is why I'd check your oil level.
The low MPG is what puzzles me. It seems like my MPG maybe improved a little whenever I've blown an injector - didn't have any power, but wasn't using as much fuel. And if your low power is due to low fuel pressure, again, you might have better MPG. If you were stuck in a low gear, I'd expect the low MPG, or towing with a stuck turbo. But just driving unloaded with a stuck turbo, I'd expect better MPG than that. It's like you're losing fuel somewhere. Which is why I'd check your oil level.
Thread Starter
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Cross-Country
Joined: Nov 2020
Posts: 63
Likes: 1
You sound like you know what you're doing, and everyone knows I don't; but, I'll throw this out anyway - check your oil level. Maybe you're losing fuel into the crankcase. Are your batteries good? FICM connections in good? And you're getting all your gears, not in 5 gear limp mode? Might as well check that your fuel bowl is filling up quickly, and while it's open do a bubble test. Is your Vref good? Check that vacuum hose coming off your passenger valve cover for cracks or holes.
The low MPG is what puzzles me. It seems like my MPG maybe improved a little whenever I've blown an injector - didn't have any power, but wasn't using as much fuel. And if your low power is due to low fuel pressure, again, you might have better MPG. If you were stuck in a low gear, I'd expect the low MPG, or towing with a stuck turbo. But just driving unloaded with a stuck turbo, I'd expect better MPG than that. It's like you're losing fuel somewhere. Which is why I'd check your oil level.
The low MPG is what puzzles me. It seems like my MPG maybe improved a little whenever I've blown an injector - didn't have any power, but wasn't using as much fuel. And if your low power is due to low fuel pressure, again, you might have better MPG. If you were stuck in a low gear, I'd expect the low MPG, or towing with a stuck turbo. But just driving unloaded with a stuck turbo, I'd expect better MPG than that. It's like you're losing fuel somewhere. Which is why I'd check your oil level.
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Fleet Owner
Joined: Nov 2003
Posts: 27,872
Likes: 3,592
You can always disconnect the EBP and see if that has any affect. It should run well enough without it (IF the sensor is the only issue).
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Joined: Sep 2003
Posts: 12,235
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From: Houston, Texas
You probably have an issue with your FICM and/or injectors especially since you mentioned the truck sounds fine but doesn't go anywhere.
With the latest flash, it's designed to cover up questionable injectors and make them perform until they can't.
It does this 1 of 2 ways:
1. Overfuels injector(s) on the opposite site of the engine to compensate for a weak injector. (spins the crank faster)
2. IF more than two injectors are failing, it brings the rest of them down to the level of the weakest injector. The truck still runs and gets down the road, but won't leave you on the side of the road....yet
The latter unless I'm sadly mistaken, is what I believe may be happening.
With the latest flash, it's designed to cover up questionable injectors and make them perform until they can't.
It does this 1 of 2 ways:
1. Overfuels injector(s) on the opposite site of the engine to compensate for a weak injector. (spins the crank faster)
2. IF more than two injectors are failing, it brings the rest of them down to the level of the weakest injector. The truck still runs and gets down the road, but won't leave you on the side of the road....yet
The latter unless I'm sadly mistaken, is what I believe may be happening.
Lead Driver
Joined: Feb 2011
Posts: 8,241
Likes: 155
From: L.A. (Lower Alabama)
hey TD!
Sound like mine did when you did the diag on it. Smooth but no power, terrible mileage. Ran like a top with new injectors. If you remember I tried to polish my spool valves and got something wrong.
My son in law had an ‘03 6.0 doing similar, he had done some exhaust work on it and suddenly no power. He had mixed up the vacuum lines for the MAP and coolant valves.
Sound like mine did when you did the diag on it. Smooth but no power, terrible mileage. Ran like a top with new injectors. If you remember I tried to polish my spool valves and got something wrong.
My son in law had an ‘03 6.0 doing similar, he had done some exhaust work on it and suddenly no power. He had mixed up the vacuum lines for the MAP and coolant valves.
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