allisnut

No codes showing on mine when the Advance Auto guy checked it.

What would be a good (hopefully low cost) diagnostic tool / tuner that would work with my iphone?

F150Torqued

Len671;


First, allow me to say "Thank you for your service in Iraq and Afghanistan" & "Welcome to San Antonio. We all wish you full recovery if BAMC is the reason you are here."


I agree the FPDM, [All due respect to @techrep] while it's a VERY common problem on our trucks and should be checked out, should not be the root cause of random misfires.


Having said that, I also say these engines are designed to run as lean as possible and MANY THINGS can result in miss firing if everything else is not working properly. Even inadequate fuel rail pressure - which I suppose could result from a faulty FDPM.


I must say I don't know about "the Lacquer Thinner trick", but I would be careful running 'off the wall' stuff through the engine for fear of damaging your CATs - which may already be suspect. But, it is impossible to say - and expensive to guess, without some good OBDII readings. ie: Fuel Rail Pressure - which, if low, should also show up in Short & Long Term Fuel Trim readings being high. A rich fuel mixture can "overwhelm" the CATs and result in overheating the pre-cat and cause the exhaust to smell (like rotten eggs). O2 sensor readings or graphs from a diagnostics scanner (I use the Android Torque Pro App) would also be informative in chasing the mis-fire problem as well as CATs.


As for your Question:

POSSIBLY - if the post CAT is crumbling and partially plugged - resulting in excessive back pressure, it could result in misfires. You did not say which cylinders were misfiring, but most likely the back pressure caused by a CAT would NOT occur on both banks equally. Other than that, both O2 sensors are in front of the second CAT which is where the smell would likely be coming from, so the PCM wouldn't even know if it isn't working right.


Good luck.

Tommy J

Read your post about cleaning the spark plug "hole" prior to new install and though Im not a technical guy, it made perfect sense to me. Im not up to the $2,500 price yet but am slowly approaching it. I used new motorcraft plugs and cops and have changed,cleaned just about everything else and cannot get rid of my low/rough idle and random miss. I do have a clogged cat/cats I believe the previous owner caused due to lack of maintenance which could be the cause of my problem. With that being said, you have me curious and after some of this snow melts Im going to go and pull one of my 3 month old plugs and take a good look at it. I may just try your process just for peace of mind. Do I have to worry about anything getting into the engine like any debis or is it minimal and will it just get burned up. truck has never thrown a code and Ford could'nt find a thing. It will probably never be a TSB because Ford is already getting grief from the broken plugs and the last thing they want to tell people is oh, by the way, you may have to clean some stuff too, you know, kind of like the throttle body. Anyway, thanks for the info. I may just do one at a time over the course of the next few weeks

vintageman

[MENTION=170523]F150Torqued[/MENTION]
Yes, I have done the diagnostic mode on my truck many times, works every time. Not sure why yours does not work though, I have also done it on my mustang and my older (1999) expedition before I sold that one. Haven't tried it on my 2010 expedition but it definitely works like I said on my 04 F150. I do have the FX4 model with the digital odometer/trip gauge? Is yours an XLT without the digital display? If so, I had a Dodge that had the basically same function but just started differently to get it into the diag mode. Turn the key on, then off, then on, then off, then on again. Wait for the gauge lights to stop the initial sequence, then count the flashes on the "check engine" and it would let me know the codes. I just had to write the number of flashes down and translate them into the appropriate 4 digit numbers to get the code.

Good luck
Tom

primalurges

You have a low grade misfire from a bad coil. Take it out on the highway and gun it with OD off until it misfires. The CEL will flash a few times before it eventually gives a permanent code identifying the cylinder. The misfire has to occur on at least three full cold to operating cycles before you get the code. It may take a few weeks.

F150Torqued

[MENTION=126521]Tommy J[/MENTION]:
I definitely used my air compressor and blew the spark plug holes out (as we should always do) before "removing plugs". But I didn't worry about any carbon getting in the cylinder from the burnishing the thread holes or below the threads. --- ((NOTE: the 2004 to late 2007 have a very different (and it could be said - stupid) head / spark plug hole design which is responsible for MUCH grief from broken spark plugs. I don't think THAT situation applies to you.)) According to RockAuto.com the plugs for a 1999 5.4L [if your still running the '99] do not appear to use the same style plug - so my plug part number and linked post may not be applicable in your case. See the plug photo in the thread at: https://www.f150forum.com/f4/5-4l-3v...09-07-a-56871/


Except however, I still firmly believe the 5.4L is designed to run as lean as possible and leaves little margin for sloppy maintenance work or operating conditions. Also, as I posted - I do not buy the crap routinely posted about replacing COP's. I know the fragile electrical connector sticks up like a sore thumb and is susceptible to being broken or "cracked" while doing any maintenance. And ANY MECHANICAL damage to the COP will result in it absorbing moisture and failing under load, but otherwise there is not a damn thing in a COP that moves, rubs, changes or wears out - just two coils of wire and some metal core sealed in epoxy. Now the boot, coil spring, and primary electrical connector are a completely different story. They must be clean, free of cracks, oil, contaminates / moisture / (salty) sweat or corrosion. The COP's electrical connectors should be cleaned with good spray electrical connection cleaner and should "snap" on firmly or the connector be replaced. Plugs must be properly gapped [mine are NOT adjustable], must not have greasy/salty finger prints on the ceramic and the boots should be REPLACED with a small amount of dielectric grease to make sure the boot slides all the way down over the plug.


Doing "one at a time" could eliminate a mistake I have made (and have seen others make), is failing to keep track of WHICH cylinder WHICH plug came out of. There can be valuable trouble shooting evidence left behind on a spark plug / boot that could help diagnose an intermittent misfire. ie: the condition of the electrode - [black/rich fuel mixture, white chalky from lean mixture, carbon buildup from burning oil, fractures or contaminates on the ceramic or evidence of arching over.]


IMO, only after a good, clean plug change and ignition wiring inspection (whether with new COP's or not), can one look elsewhere for intermittent misfires.


ANOTHER THING, I am a firm believer in doing a complete "BATTERY DISCONNECT" reset and perform a "RELEARN" procedure on the PCM after ANY part change or significant maintenance. This forces it to recalculate any fallback or compensation(s) for abnormal sensor inputs. Oft times it will produce a completely different code leading to a completely different failing part.


I'm not a mechanic, just a curious / logical / well seasoned guy, so can only hope there is some wisdom for you here. I know the from experience the intermittent misfire / shutter / loss of power sensation is frustrating problem.


As always - Good Luck

Bones82

I had the same "issues" with my '08 SCAB. I received multiple misfire codes upon scanning as well as the Ford "check engine" light flash/code on the dash. Once I replaced ALL 8 plugs and COP's, the issue was resolved. I'm cheap, so I had a hard time buying 2 COPs for $49/ea when I could buy all 8 for under $200. So far she's been running like the day she came off the line. Let's just hope it stays that way! Good luck! (Let me know if you need a Lisle Tool)

LEN671

F150Torqued,
Thank you for support and your response as well. Yes, I am being treated at BAMC for my burns and other physical injuries. As far as the codes I am receiving, they are as follows:
- P0300
- P0302
- P0306
- P0307
- P0316
- P1000

I am going to try SeaFoam through the Gas tank and see of that helps anything.

Thank you all again for your advice and knowledge.

F150Torqued

I don't doubt you - but I just went back out to my truck and almost wore the ignition switch out trying every combination imaginable - No Joy.


What pisses me off is this. As simple as it would be for ANY ECU to do this, it should be a standard (and published / advertised) feature on every OBDII equipped vehicle.


I think I will start a dedicated thread in the Maintenance Shop about this and see if we can drum up any more information about it. The new thread is here: https://www.f150forum.com/f12/diagno...isplay-294625/


Thanks for the useful info .

0488FB

allisnut;


My 2007 had same shudder as described in your original post. 2 weeks ago I pulled our 25' toyhauler four hours and the truck didn't miss a beat when running out of O/D. On a few long down hills, tried O/D and just as it was down shifting, it would shudder then go out of lock-up. Search on here turned up to change the trans fluid/filter. Autozone Duralast filter, 5qts Castrol MerconV, reuse original gasket. Shudder gone! If your not throwing any codes, and the shudder is as described in first post, you might want to give this a try. My truck has 106,600 miles and was original fluid cause I found the mysterious white plug in bottom of pan. I bought it with 83,700 in July 2013. If this doesn't work and the truck is in need of trans service, money/time still not wasted. Just my $.02.