2004 F150 Rich at idle, Lean under load
#1
02-07-2015, 12:25 AM
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2004 F150 Rich at idle, Lean under load
Background:
I purchased my 2004 F150 FX4 in November 2014. It has the 5.4 L 3v Triton with 130k miles. A week after purchasing I was misfiring really bad. Code pointed to cylinder 4. Took it to my mechanic and had new motorcraft plugs put in. Ran great post plugs.
A week later it started to run rough again, misfiring and throwing codes. Among the codes were misfire cylinder four again and now a lean bank 2 code. I did manage to pick up a bosch oxygen sensor fairly cheap so I put that in myself and reset codes with a battery unplug. After that I have not received a lean code on the truck.
I took it to the family mechanic and he diagnosed the misfire to be the boot to cylinder four. It was sparking down the side of the porcelain. At this point the truck was still not throwing a lean code or even a misfire for the mechanic, mind you it was running pretty bad. I told him since I bought all new plugs I would go the extra mile and replace all the cop's. I purchased Accel's, he put a new spark plug in at cylinder four when replacing the cop's and all was well as far as misfires.
During diagnosing/and after cop's he stated it was lean under load. But not during idle. I dont want to state this wrong but im pretty sure he explained like it was just under the lean amount to throw a code on both banks. (a number of 29 and 30 or more would throw it?)
I was on my way with what seemed like a new truck after dealing with all the misfires. Since then ( a week or so ) I have 1 code which he explained to me as misfire cylinder 8 on cold start (first so many revolutions?). That is not my biggest concern. The lean part is puzzling me, and he was on the fence of it being a MAS. Which by the way he cleaned during service. I notice a power loss or slight sluggishness under acceleration. Not its full potential lets say.
Which led me back to my mechanic today. He put a similar MAS in today and we tested it out. With no luck it didnt seem to help. So I guess after all that explanation and background, my concern is where do I go next. Budget is limited, and concern is high. My mechanic said since it idle'd fine and was only lean per say while driving he didnt think it was a vacuum leak. I read somewhere in these forums that the 04' and 05's had lean issues. The forums said something about it dosnt have a MAF metering system which wouldn't allow it to adjust automatically? The MAF system run a MAS system? Not sure if what I explained there made any sense.
I apologize in advance if this is to long or dosnt make any sense. I had typed this all up once already and the site screwed up making me re-login. Any help and or guidance would be great. Do they make an adjustable MAS for this truck? Is there something I should check, or a common problem I should be aware of?
Thank you in advance!
I purchased my 2004 F150 FX4 in November 2014. It has the 5.4 L 3v Triton with 130k miles. A week after purchasing I was misfiring really bad. Code pointed to cylinder 4. Took it to my mechanic and had new motorcraft plugs put in. Ran great post plugs.
A week later it started to run rough again, misfiring and throwing codes. Among the codes were misfire cylinder four again and now a lean bank 2 code. I did manage to pick up a bosch oxygen sensor fairly cheap so I put that in myself and reset codes with a battery unplug. After that I have not received a lean code on the truck.
I took it to the family mechanic and he diagnosed the misfire to be the boot to cylinder four. It was sparking down the side of the porcelain. At this point the truck was still not throwing a lean code or even a misfire for the mechanic, mind you it was running pretty bad. I told him since I bought all new plugs I would go the extra mile and replace all the cop's. I purchased Accel's, he put a new spark plug in at cylinder four when replacing the cop's and all was well as far as misfires.
During diagnosing/and after cop's he stated it was lean under load. But not during idle. I dont want to state this wrong but im pretty sure he explained like it was just under the lean amount to throw a code on both banks. (a number of 29 and 30 or more would throw it?)
I was on my way with what seemed like a new truck after dealing with all the misfires. Since then ( a week or so ) I have 1 code which he explained to me as misfire cylinder 8 on cold start (first so many revolutions?). That is not my biggest concern. The lean part is puzzling me, and he was on the fence of it being a MAS. Which by the way he cleaned during service. I notice a power loss or slight sluggishness under acceleration. Not its full potential lets say.
Which led me back to my mechanic today. He put a similar MAS in today and we tested it out. With no luck it didnt seem to help. So I guess after all that explanation and background, my concern is where do I go next. Budget is limited, and concern is high. My mechanic said since it idle'd fine and was only lean per say while driving he didnt think it was a vacuum leak. I read somewhere in these forums that the 04' and 05's had lean issues. The forums said something about it dosnt have a MAF metering system which wouldn't allow it to adjust automatically? The MAF system run a MAS system? Not sure if what I explained there made any sense.
I apologize in advance if this is to long or dosnt make any sense. I had typed this all up once already and the site screwed up making me re-login. Any help and or guidance would be great. Do they make an adjustable MAS for this truck? Is there something I should check, or a common problem I should be aware of?
Thank you in advance!
#2
02-07-2015, 12:38 AM
2 mistakes.
1. Replacing an O2 sensor for a lean code. The sensor was doing its job reporting a lean condition. Lean codes are almost always caused by a vacuum leak or unmetered air entering the intake after the MAF sensor. You have a MAF sensor, not a MAS or MAP. If you have an aftermarket intake, such as a K&N, that's causing it to run lean because the MAF is not measuring the airflow correctly.
2. Accels are not good coil on plug units. The boots on the stock ones are replaceable.
Drop the spare tire and unbolt the FPDM from the crossmember, check the backside for corrosion. If it looks nasty, replace it with a Motorcraft unit - NOT a Dorman.
1. Replacing an O2 sensor for a lean code. The sensor was doing its job reporting a lean condition. Lean codes are almost always caused by a vacuum leak or unmetered air entering the intake after the MAF sensor. You have a MAF sensor, not a MAS or MAP. If you have an aftermarket intake, such as a K&N, that's causing it to run lean because the MAF is not measuring the airflow correctly.
2. Accels are not good coil on plug units. The boots on the stock ones are replaceable.
Drop the spare tire and unbolt the FPDM from the crossmember, check the backside for corrosion. If it looks nasty, replace it with a Motorcraft unit - NOT a Dorman.
#3
02-07-2015, 01:03 AM
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Ill be honest I only replaced the oxygen sensor due to my mechanic out of town and I was impatient. The accel's were rated better than some and I figured it was an affordable gamble knowing my current cop's had a few good one's left. I do not have an aftermarket intake. And I am unsure as to what an FPDM is, but i will absolutely be looking that up after this reply. Thank you for your reply, from all my lurking on ford forums I have noticed one thing that is constant. People sure love to let someone know when they bought junk, lol. My budget controls most of my purchases, sad truth.
#4
02-07-2015, 06:49 AM
Ill be honest I only replaced the oxygen sensor due to my mechanic out of town and I was impatient. The accel's were rated better than some and I figured it was an affordable gamble knowing my current cop's had a few good one's left. I do not have an aftermarket intake. And I am unsure as to what an FPDM is, but i will absolutely be looking that up after this reply. Thank you for your reply, from all my lurking on ford forums I have noticed one thing that is constant. People sure love to let someone know when they bought junk, lol. My budget controls most of my purchases, sad truth.
One of the opportunities a lot of folks miss is leveraging all the vast archival data on the site - by researching first, one would hope to be avoiding buying junk in the first place. Sadly, the corollary is true - folks seldom do any research - hence end up with junk. And all of the time we spend endlessly posting and re-posting what works is squandered.
Standard checklist:
1. Post ALL the actual codes
2. What plugs were used? (Motorcraft only)
3.. What COPs were used? (Motorcraft or Visteon only)
4. Were new boots and springs used, WITH proper application of dielectric grease? https://www.f150online.com/forums/20...ml#post5128817
5. Check yer FPDM: https://www.f150online.com/forums/v8...placement.html
6. Replace BOTH front O2's (80K maintenance item - Motorcraft preferred - Bosch 'okay')
7. Check injectors fer leakage.
8. Other maintenance - clean yer MAF & TB. Replace the fuel filter - it's a yearly maint item anyway.
9. Monitor VCT PIDs for abnormal operation
10. perhaps in your case, find another mechanic. This one dos not seem to have a lock on a Ford Triton, based upon what was stated to-date. Sorry - no offence.
good luck
MGD
#5
02-09-2015, 02:49 PM
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It has crossed my mind if this situation would be better suited for a ford specific mechananic. My mechanic has been good to my family and is usually very knowledgeable. Anyhow I think I will start with replacing my fuel pump since I don't know when that was last done. And then while doing so I'll check my fpdm. I used the right plugs and just couldnt afford the mc cop's. So it wasn't a matter of un educated. You can't always afford the best in life, sorry just how it is for some of us. As far as checking for injector leaks I'll have to research and see how to go about that. Is it true newer Injectors are less likely to clog? And if that's not true, would running some cleaner through be helpful? Again thanks in advance.
#7
02-09-2015, 03:32 PM
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#8
02-09-2015, 10:50 PM
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Would I seriously be that much better off putting Motorcraft COP's on? Enough to justify another $160? If so I am seriously considering returning my Accels to do so. After the amount negative and strong opinions in all the forum posts including my own I have been a bit upset about my purchase.
