BajaNomad

Engine Problem

SFandH - 7-10-2016 at 08:47 AM

I know there are many nomads who are good mechanics so I thought I'd solicit some opinions.

My 5.4 liter F-250, 150,000 miles, stumbles under light acceleration. It's a reproducible problem. If I accelerate normally to 2000 rpms all is good. But if I take my foot off the gas, let the rpms fall to say 1200 rpms and then lightly accelerate so the transmission doesn't downshift the motor noticeably stumbles at about 1500 rpms. I'm thinking about adding a fuel injector cleaner to the gas as my first option.

Watcha think?


[Edited on 7-10-2016 by SFandH]

Hook - 7-10-2016 at 09:01 AM

The injector cleaner cant hurt. I really like the Lucas Oil one. I live in Mexico and my Jeep seems to need a treatment every three months or so, though it never needed it in the US.

Also try replacing any and all fuel filters and make sure your air filter is clean. Those are the easy things to try.

Is the "check engine" light on? If so, go by an Autozone and have them read out the codes.

[Edited on 7-10-2016 by Hook]

TMW - 7-10-2016 at 09:01 AM

I think that is a good place to start. Did it just start doing this recently?

SFandH - 7-10-2016 at 09:02 AM

I noticed it about a month ago, the problem went away, and then returned yesterday.

No check engine light. I have a code reader.

[Edited on 7-10-2016 by SFandH]

TMW - 7-10-2016 at 09:04 AM

Can you relate it to a gas station.

SFandH - 7-10-2016 at 09:06 AM

I use the same gas station for my car. No problems with it.

Hook - 7-10-2016 at 09:09 AM

Is it happening in really hot conditions? Yesterday was really hot in the entire SW and all of Baja. Was it really hot when it started a month ago?

Where are you?

SFandH - 7-10-2016 at 09:17 AM

Yesterday I was on the toll road north of Rosarito. Not hot.

I'm really paranoid about transmission problems since over the years I've had two fail in baja, causing major headaches. Further Inet reading indicates it's a fuel or ignition problem. So far I haven't read anything pointing to the transmission.

I'll look into throttle position sensors, thanks for the suggestion.

[Edited on 7-10-2016 by SFandH]

Bob and Susan - 7-10-2016 at 09:20 AM

Quote: Originally posted by lencho  
Quote: Originally posted by SFandH  
..then lightly accelerate so the transmission doesn't downshift the motor noticeably stumbles at about 1500 rpms.

Throttle position sensor?


I think that's what it's called...the vaccuum hose fell off...
its way back by the fire wall behind all the intake "stuff"

probably no part needed...just reattach the hose...you may not be able to see its off from the front...you need to climb on top of the engine and reach in

either that or its the fuel pump wire inside the tank...i'd get a new pump even though you can fix this
you need to take the tank out...if its out just replace the pump

i'll bet a loose hose...

tell us later what it was...

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Bob and Susan - 7-10-2016 at 09:35 AM

this is the guy to go to for transmission rebuilding...they have a "wear-house" of transmissions there...

here is a video
they are in sunland ca just north of Burbank

https://www.youtube.com/watch?v=BFIJB5n3BYQ

Hook - 7-10-2016 at 09:45 AM

I think if that hose was off, it would be happening a lot more than the situation he is describing. But it's an easy check. Look for ANY vacuum hoses that are off.

I also think if it was the throttle position sensor failing, a code would be thrown.

Very unlikely that it is transmission related. Fuel related would be my first guess, then electronically-controlled fuel components, then ignition. Ignitions don't go south too much anymore (except for German cars, LOL!). So, check the easy mechanical fuel items like filters first.

If the "lift" type pump in the fuel tank is failing for whatever reason, you typically wont be able to drive up a hill without the engine stumbling. And that is such a PITA repair that only consider doing that when all else has failed.

Bob and Susan - 7-10-2016 at 09:56 AM

Quote: Originally posted by Hook  
I

...I also think if it was the throttle position sensor failing, a code would be thrown...

...If the "lift" type pump in the fuel tank is failing for whatever reason, you typically wont be able to drive up a hill without the engine stumbling. And that is such a PITA repair that only consider doing that when all else has failed.


no code if the throttle sensor has a leak...ford didn't use a hose clamp...you should add one but its harder than hell to tighten

if the fuel pump is failing...it may be the ground wire and it goes on and off...if you hit a bump the engine may stall...it'll idle bad

willardguy - 7-10-2016 at 10:58 AM

Quote: Originally posted by lencho  
Quote: Originally posted by SFandH  
..then lightly accelerate so the transmission doesn't downshift the motor noticeably stumbles at about 1500 rpms.

Throttle position sensor?


:yes:.......clean the MAF/throttle body?

Hook - 7-10-2016 at 11:21 AM

:yes:.......clean the MAF/throttle body?

Are you talking about Mass Liquid Flow, while you throttle a body?

If so, yes, I prefer both components to be clean as possible. :smug:

A Willarguy post deserves a Willardguy reply............:lol:

willardguy - 7-10-2016 at 11:34 AM

Quote: Originally posted by Hook  
:yes:.......clean the MAF/throttle body?

Are you talking about Mass Liquid Flow, while you throttle a body?

If so, yes, I prefer both components to be clean as possible. :smug:

A Willarguy post deserves a Willardguy reply............:lol:


:lol:....mass liquid flow WILL lead to stumbling!

woody with a view - 7-10-2016 at 02:39 PM

Your answer lies within......

https://www.google.com/search?q=5.4+liter+F-250%2C+150%2C000...

fishbuck - 7-10-2016 at 03:12 PM

I have the same motor, same issue.
It does't like to run at low rpm where is doesn't have much torque.
I'm guessing spark plugs. The fire goes out.
It's a horsepower motor like all gasoline powerplants.
It loves high rpm.
The spark plugs are a pain to remove and are prone to breaking during removal.
A special tool is required or I would have done it by now.
Manually downshift it. And let it roar. That's what it likes.

SFandH - 7-10-2016 at 04:22 PM

Lots of info on the Internet. All sorts of misfiring issues with this motor. Too bad, but it has been running perfectly for years.

I'm going to run some gas cleaner through the fuel system for a while and see what happens. It's an easy/cheap first step. I've read several mentions of the Lucas cleaner being good stuff.

I couldn't find any detached vacuum hoses.

The fact that it stumbles only around 1500 rpm in high gear under light acceleration must point to a specific problem, what I don't know. And when it stumbles it STUMBLES, it's like I'm hitting bumps in the road, very noticeable.

Hook - 7-10-2016 at 05:20 PM

Is this one of those engines that only fires a limited number of cylinders at certain RPMs?

Bob and Susan - 7-10-2016 at 05:46 PM

Quote: Originally posted by SFandH  
...I'm going to run some gas cleaner through the fuel system for a while and see what happens. It's an easy/cheap first step. I've read several mentions of the Lucas cleaner being good stuff.

I couldn't find any detached vacuum hoses.


there is NO cure for the common cold...don't waste your money on gas cleaners

the pipe larry was talking about is behind the throttle body...you can barely see it fron the front...you have to reach in...

I replaced mine...$30...a guy in California told me and the mechanic in mulege knew right away...he just reached in and plugged it back in...

again its way in the back

when my fuel pump went out...it would stall on speed bumps...and idle bad too...up and down

go see a mechanic...they will know...its not gas or plugs

pacificobob - 7-11-2016 at 06:26 AM

Quote: Originally posted by lencho  
Quote: Originally posted by SFandH  
..then lightly accelerate so the transmission doesn't downshift the motor noticeably stumbles at about 1500 rpms.

Throttle position sensor?


yes, i would check the TPS, also O2 sensor.....

mtgoat666 - 7-11-2016 at 06:42 AM

should have bought a Toyota!

SFandH - 7-11-2016 at 08:23 AM

Quote: Originally posted by Hook  
Is this one of those engines that only fires a limited number of cylinders at certain RPMs?


It's not supposed to be but it seems to be somewhat so. ;)

SFandH - 7-11-2016 at 08:54 AM

Connected my OBD II code reader and it's telling me P0304, "cylinder 4 misfire" and P0316 "Misfire detected 1st 1000 revs."

Of course the number 4 cylinder is in the back, passenger side and the back 1/2 of the motor is under the windshield cowling, tough to see let alone get to.

Hmmm, what's the fix to clear these codes?

[Edited on 7-11-2016 by SFandH]

woody with a view - 7-11-2016 at 08:59 AM

Google is your friend. Start with the cheap items.

SFandH - 7-11-2016 at 09:09 AM

Yeah lots of info on google for P0304.

Plug, plug wire, ignition coil, fuel injector. Need to start narrowing it down. Plugs were changed 30,000 miles ago.

Just started the truck again and the check engine light came on.

[Edited on 7-11-2016 by SFandH]

TMW - 7-11-2016 at 11:08 AM

I would check the fuel pressure before doing any serious repairs.

In Jan. I did a Baja trip and on the way home my 04 GMC started missing and the check engine light came on. The OBDII test showed a misfire. I was able to drive it home without any problem but within a mile of home it really got bad. Had AAA take it to my mechanic and he found the fuel pump was bad. That was the third fuel pump in 150,000 miles.

woody with a view - 7-11-2016 at 12:48 PM

Not sure how yours is but my coil packs are on top of each spark plug boot. If this is your issue you should be able to move the suspect coil to another cyclinder and the code should follow you.

Bob and Susan - 7-11-2016 at 01:18 PM

woody's right...switch 'em ...if that's it then the problem will follow

one of my cables broke...the screw area that holds it in place...it would flop around and cause a misfire...make sure they are all secure

but a code misfire on#4 is probably the fuel pump

my 5.4 had this issue...first we fixed a wire in the tank
then later we replaced the pump...when it stopped working of course

the check engine light CAN come on because you have dirty battery cables...it resets by disconnecting the ground wire

did you take off the idle valve behind the intake to see if its clogged...2 bolts does it
its electric so its like a light bulb...it can go out any time

sometimes its better to understand you are beaten and take the beast in to the shop and let the professionals operate...that's what they do

SFandH - 7-11-2016 at 01:38 PM

Quote: Originally posted by Bob and Susan  


but a code misfire on#4 is probably the fuel pump



Hmmm, do you have some reasoning behind that conclusion.

Call me crazy but I'm thinking a cylinder #4 misfire probably has something to do with the gizmos, widgets, and gadgets associated with cylinder #4.

TMW - 7-11-2016 at 01:57 PM

If the fuel pump is intermittent you won't get a good fire in one or more cylinders. The code can't tell you the pump is bad only the results from the pump being bad.

Bob and Susan - 7-11-2016 at 02:08 PM

tmw is right ...

it could be as easy as a ground wire for the pump...

my f250 is a "rust bucket"
i'm always having problems with grounds

don't you just hate it when part of your fender falls off...



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BajaBreak - 7-11-2016 at 02:24 PM

Not Sure if you have the era of Triton's that had the spark plugs stripping out of the head, but maybe look into the symptoms of that. Seems too specific for that. I'm trying to resolve a similar lag, and am hoping advancing the timing will help. Need to move the crank sensor b/c timing is controlled by the ecm on mine. It gets retarded over time as the distributor wears.

Happy part shopping!

SFandH - 7-11-2016 at 02:27 PM

Well that sucks. I thought I was zeroing in on the problem and you guys add another possibility, a faulty fuel pump.

I'm still hoping for a dirty injector and the $5.00 fuel cleaner additive will fix it. I'll give it 100 or so miles. I know, slim chance, but I'm in no hurry.

[Edited on 7-11-2016 by SFandH]

willardguy - 7-11-2016 at 02:46 PM

yeah great idea to peck away at cheap stuff that could use replacing anyway!:yes:

BajaBreak - 7-11-2016 at 03:45 PM

Keep any old parts that were known to be functioning for a little Baja spare parts kit. That way you don't have to feel like you wasted too much money on unnecessary stuff.

SFandH - 7-19-2016 at 02:17 PM

The cylinder #4 misfire is boiling down to be an intermittent problem. I have about 200 miles on the tank with the Lucas fuel treatment and it seems to be less of a problem, more difficult to reproduce.

I went for a ride today and all was fine for the first 30 miles, I couldn't get it to misfire, then it started to stumble badly. That lasted for maybe 5 miles and then it smoothed out. I couldn't get it to misfire again at any rpm/speed/gear combination.

Does that narrow it down? I'd like to have a good idea of what the problem is before I take it to a mechanic.

I'm thinking about digging into it myself. What should I test first? Lots of videos on youtube about changing plugs, injectors, coils on the exact motor so I won't be going in blind. 2003 Ford 2 valve 5.4 liter.

I have until October to get things ship shape. Then I'll be heading to BCS for the winter.

[Edited on 7-19-2016 by SFandH]

taoswheat - 7-19-2016 at 03:22 PM

Just a thought- When I have a tough problem I go to justanswer.com. It costs a bit but there are many professional mechanics with factory failure information and repair data just waiting to work on your problem.
JohnW
Taos, NM

SFandH - 7-19-2016 at 03:31 PM

Thanks John, that's an idea.

Gotta get to Taos someday.

55steve - 7-19-2016 at 03:37 PM

150,000 miles - have the plugs & wires ever been changed?

Hook - 7-19-2016 at 04:19 PM

When anything is intermittent without unusual external environmental conditions, I always suspect an electric/electronic problem first. this is different than the lagging acceleration you mentioned at first. Mechanical things fail and stay failed.

Replace cheaper things first.

Dont know why a problematic fuel pump would only manifest itself on a specific cylinder. A cylinder misfire is probably electrical/electronic.

Is swapping the sparkplug wire from one of the other cylinders possible, to see if the problem moves to a different cylinder? Changing sparkplug wires isn't as easy as it used to be.

Know anyone REALLY WELL with the same engine that will allow you to swap out a few things to try and eliminate things without actually having to buy parts? Fuel pump? Wires to and from the distributor?

Let's hope it's not a Power Control Module or the module that controls the fuel injection circuit, if you have one. They are probably expensive and probably only available from the dealer. Replace other things first.

Someone mentioned a known issue with the sparkplugs stripping out their threaded bases. I always assumed that solid contact with their threaded bases is how sparkplugs achieve "ground" in order for the spark to cross the gap when electricity is supplied to the electrode. Can you get at that sparkplug with your fingers and wiggle it and see if you feel a looseness in how it is mounted? Maybe there are times when it isnt achieving "good ground" due to it's threaded mount being compromised.

On my Ford diesel, there was a known issue where an injector wiring harness (mounted to a valve cover) became loose after years of heating up and cooling down. See if you can trace any wiring harnesses that send signals to individual cylinders. Maybe there is a wiring junction/plug that has become loose or compromised.

I dont know much about your engine. Diesels are direct injection into each cylinder. Gas engines may be a single throttle body injector.

SFandH - 7-19-2016 at 04:34 PM

each cylinder has an injector and coil on top of the plug

swapping plug wires to see if the miss moves with the wire sounds like an easy thing to do.

thanks, i'll try that first

[Edited on 7-20-2016 by SFandH]

Bob and Susan - 7-19-2016 at 06:19 PM

my engine is EXACTALY the same as yours...

the missing like you experienced was the fuel pump in the gas tank

the rough idle was the idle sensor thing

when the tank was full of gas it didn't vent well and idrilled a hole in the gas cap...worked too

when the pump finally died I hit a bump and it was gone
like a lightbulb

end the pain and replace the fuel pump

today my 2 year old battery died at the Pemex station...the operators at the Pemex called my mechanic...the brought a battery and fixed the cables...great service...truck runs like new again...we checked the battery at the shop and it truly died...alternator fine...new cars are just better because they haven't worn out yet

KaceyJ - 7-19-2016 at 07:45 PM

That reminds me Bob, Low voltage can cause a problem in itself ,.

Not enough juice to run all the sensors and control systems.

I agree on the fuel pump

Hook - 7-19-2016 at 08:33 PM

Low voltage isnt likely to cause a problem while you are at speed, unless you're alternator is shot. Your standard 90+ amp alternator will more than make up for a bad battery while running.

This assumes that you are NOT getting too much resistance from your battery leads or somewhere else. BE VERY SURE THEY ARE THOROUGHLY CLEANED AND TIGHTENED! They can pass voltage but sometimes not enough current (amperage) if there is corrosion preventing it.

OK, lets consider the fuel pump as a possibility, since so many are demanding it.

Since you are injected, you likely have a fuel pump that brings the pressure up to what the injectors need. The pump in the tank is not that, usually; the tank pump is considered a primary"lift" pump (low pressure pump) to simply get the fuel out of the tank to a secondary (high pressure) pump. CHECK THE SECONDARY PUMP FIRST, before you decide to drop your own fuel tank or pay someone the money to do it. It's often mounted along the "rail" (inside your chassis member that runs front to back where the fuel line runs). While the vehicle is running take voltmeter readings at it's connections to make sure it is getting voltage within 0.1-0.2 volts of what you are reading at the battery. Check for corrosion at it's leads. Certainly the reading should be well above 13 volts while the engine is running.

If voltage appears normal, get a price on replacing that and see if it is reasonable enough to justify it. You should be able to find a replacement outside of the dealer network. Check a Napa auto parts store. They seem to carry more non-Chinese replacements than all the others. I'm not a gung-ho, buy American first guy; I've just experienced too much Chinese junk.

But DO THE SPARKPLUG THING FIRST! It costs nothing but time.

Usually, when a lift pump is failing, you will experience problems when climbing hills. The incline forces the lift pump to lift fuel higher and it starves the secondary pump. Have you noticed that the problem occurs on inclines?

To Bob: yeah, it really sucks how short battery life is down here. I installed brand new Interstate batteries in my truck when I moved down here. They were six year guarantee batteries and only lasted about 2.5 years. The heat just cooks them. Of course, I was not going to drive them back up for my warranty claim.

So, I buy the best LTH or the best Duralast batteries at the Mex Auto Zone and hope I get three years. I am buying new ones next week, before I go NOB. I have an idea that raising my hood at the end of the day and venting all that built up heat may extend their life. Just a hunch. Plus the gassing in all that heat has me constantly fighting corrosion on the battery leads. Even a combination of those "wool" pads around the terminals and the anti-corrosion spray is not 100% effective.

Bob and Susan - 7-20-2016 at 05:23 AM

Quote: Originally posted by KaceyJ  
That reminds me Bob, Low voltage can cause a problem in itself ,.

Not enough juice to run all the sensors and control systems.

I agree on the fuel pump


that's exactly right...

the battery cables at the battery corrode ALOT
i'm always fighting them
vasiine seems to work the best but once cleaned they never stop corroding

the lower voltage would flip a code and the engine light will come on if they are dirty...

I imagine the current to the pump is lowered too and the lower current could be "frying" it...remember lower current higher amps (heat)

there is only one pump hook...these are not diesels or fancy race trucks

forget taking the time with the spark plugs...new plugs HAVE to last 5ok miles by law...they last much longer

when you replace the pump replace the filter too...you may need to bleed the system the first couple miles to clear out the "air bubbles" you let in when you opened the lines

my truck runs 5 days a week pulling a 5000 pound trailer...its has to run good or i'm screwed...its a work horse I don't have to wash...for sure not the best truck I've owned but up there


SFandH - 7-20-2016 at 08:57 AM

Bob, hook and others,

I appreciate the replies and the discussion. The gas tank is low and I was going to fill it but decided not to in case it needs to be dropped to change the pump.


[Edited on 7-20-2016 by SFandH]

Hook - 7-20-2016 at 09:39 AM

I have learned so much from discussion boards that are specific to my vehicle. Have you found a good board that discusses problems with that engine and/or vehicle? It's better than a Baja board.

Don Jorge - 7-20-2016 at 09:54 AM

Quote: Originally posted by SFandH  
Quote: Originally posted by Bob and Susan  


but a code misfire on#4 is probably the fuel pump



Hmmm, do you have some reasoning behind that conclusion.

Call me crazy but I'm thinking a cylinder #4 misfire probably has something to do with the gizmos, widgets, and gadgets associated with cylinder #4.


We have a few of those engines in delivery vans. I would put a new coil, boot/wire and spark plug in the #4 slot. They are notorious for failing eventually and especially if you wash down the engines. We have had several failures over the years like the one you describe and changing out the
coil assembly and plug has worked. The fact it is kicking out a code specific to #4 is a there's your sign moment.

Of course the #4 on a pickup truck is a real beetch to get to. If you have not already done it think about changing em all out. You have some mileage under the hood.

SFandH - 7-20-2016 at 10:02 AM

Yes, I've been reading several message boards. But I haven't found much about intermittent misfires on a single cylinder. One interesting development is the Lucas fuel treatment did change the misfire from real easy to reproduce, 1500 - 1800 rpm, high gear, light acceleration to not so easy to reproduce. Could be coincidence. Like I said yesterday I couldn't get it to misfire for 30 miles or so on the freeway, playing with the gas petal to get different rpm/gear combos, but then all of a sudden it stumbled badly for 5 minutes at different loads and then smoothed out.

I've also erased the diagnostic codes once, P0304 came back and the check engine light came back on.

I know I could just take it to a shop and probably get it quickly fixed but since I drive a lot in baja it's good for me to know how these things work. Plus I'm in no hurry.

I bet it has something to do with the air, fuel, or ignition. :lol:

Right now I'd bet on the coil, agreeing with Don Jorge and his experience. If so, I'll need to decide whether to change just #4 or all 8 of them, about $40 each. Significant for my thin, retired wallet.


[Edited on 7-20-2016 by SFandH]

BajaBreak - 7-20-2016 at 12:04 PM

The stripped spark plug threads in the head issue I mentioned was on a friends 5.4L Triton, but I believe it was a '98? He told me they literally only have 3 threads holding them in. I just now read you have an '03, and am not sure if it was changed by then.

I'd be careful removing the coils, and when re-torqueing them. Avoid yanking them side to side, just try to twist and pull. I'll try asking what his symptoms were, but I recall he just said it runs like crap ;)

woody with a view - 7-20-2016 at 01:19 PM

Change out #4 and buy a spare just in case. I carry one with me on every trip SOB. Now that I do it will never be needed.