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1998 5.4l 2v performance issues

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Old Jul 2, 2012 | 12:15 PM
  #1  
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1998 5.4l 2v performance issues

I'm having huge problem with this engine just falling flat on its face anytime I need power. It happens all the time but I really notice it when I'm towing. Overdrive has no power at all, it can't even maintain speed on a flat road. It will shift into the passing gear and then just die. I have no change in power or RPM through the range of the gas pedal. I can then floor it and get her to down shift into 2nd but I don't like racing the engine that fast.<?xml:namespace prefix = o ns = "" /><o></o>
I'm not towing anything all that heavy, this truck should be able to haul a 1.3k slide in camper without a problem. I noticed this when I was towing my car home, and I started to notice it when it's just me and the truck. <o></o>
Does anyone have any ideas as to what the problem is? I've already run fuel injector cleaner through it and I'm checking the air filter as soon as I get home tonight. The air filter is a K&N btw. I did not install this it came with the truck.<o></o>
<o> </o>
Thanks in advance for any suggestions!<o></o>
<o> </o>
-Jason
 
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Old Jul 2, 2012 | 05:02 PM
  #2  
enriched&beyound's Avatar
enriched&beyound
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From: NE Iowa JD Country
Originally Posted by knuckle66
I'm having huge problem with this engine just falling flat on its face anytime I need power. It happens all the time but I really notice it when I'm towing. Overdrive has no power at all, it can't even maintain speed on a flat road. It will shift into the passing gear and then just die. I have no change in power or RPM through the range of the gas pedal. I can then floor it and get her to down shift into 2nd but I don't like racing the engine that fast.<!--?xml:namespace prefix = o ns = "" /--><o></o>
I'm not towing anything all that heavy, this truck should be able to haul a 1.3k slide in camper without a problem. I noticed this when I was towing my car home, and I started to notice it when it's just me and the truck. <o></o>
Does anyone have any ideas as to what the problem is? I've already run fuel injector cleaner through it and I'm checking the air filter as soon as I get home tonight. The air filter is a K&N btw. I did not install this it came with the truck.<o></o>
<o> </o>
Thanks in advance for any suggestions!<o></o>
<o> </o>
-Jason
Fuel filter been changed?

really shouldn't tow in OD...even that little bit...tempting I know.

has the air filter been cleaned lately....maybe over oiled....that oil can really mess with MAF sensor.....clean the MAF sensor
 
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Old Jul 2, 2012 | 05:51 PM
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I'm taking out the K&N filter and I'm going to put a stock one in place. I'm also going to buy a can of MAF cleaner and give that a good once over. I was also thinking about cleaning the throttle body. The truck has 103K on it and as far as I know it's never been done.

Where is the fuel filter btw? Please don't say in the tank.
 
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Old Jul 2, 2012 | 06:54 PM
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Filter is pretty much directly under the drivers seat in the frame rail, you need the removal tool to disconnect the lines. Spray WD40 in the clamps then put the tool in and twist it a lot then hopefully push it in AND pull the line onto the tool and the spring will release, fingers crossed. There is both a set of plastic tools or a steel "X" two size tool, I like the steel better.

TO give you an idea of the tool:
https://www.google.com/search?q=ford...FoLE2wXI5PClAg

What RPM are you scared to rev it at? IT can go up to about 5500 and 6K from 1-2, and running 3K for extended periods isn't an issue. I was used to old push rods and when I first got mine and it downshifted to almost 6K I thought I killed it.
 
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Old Jul 2, 2012 | 07:46 PM
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Originally Posted by galaxie641

What RPM are you scared to rev it at? IT can go up to about 5500 and 6K from 1-2, and running 3K for extended periods isn't an issue. I was used to old push rods and when I first got mine and it downshifted to almost 6K I thought I killed it.
upwards of 5k. I don't like keeping it there for long. Like mountain climbing you know. Should I replace the filter? I'm not 100% it's starving for gas but I'm willing to try almost anything.

The flip side to this is that I'm getting horrible gas mileage. I brought the slide in camper home it was only 176 miles and it took an entire tank of gas to make that happen. I have less than an 1/8 left on the gauge.
 
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Old Jul 2, 2012 | 09:09 PM
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yeah... that does seem a bit thirsty , and it should at least maintain speed on the level road. Were you trying to maintain 55-60 MPH or 70-75MPH?

stick with the basic maintenance to start with....make sure your not low on tranny fluid??.... and change the PCV and fuel filter, clean MAF, clean the throttle body housing, check for vacuum leaks...etc

then move on to maybe new plugs, with 103k on it ...its due, unless already recently done?

galaxie641...is right those fuel lines can be a bit stubborn to get loose sometimes...I also prefer the metal fuel line tools
 
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Old Jul 3, 2012 | 10:14 AM
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So today I cleaned the MAF and the TB. I didn't need to replace the K&N because that filter is no longer in there. It has a brand new one in it already. So I just cleaned everything up really good beause the basket and hoses were nasty.

The TB was horrible also. The intake is just as bad. It's covered in this thick oilly mess. I cleaned as much as I could. What's that stuff you can buy to clean that with? Also what is that second sensor after the MAF?

Someone also told me to reset the pcm by removing the negitave cable after I cleaned the TB. Do I need to do this?

While I'm throwing the kitchen sink at this what else should I do? I haven't looked at the fuel filter. Do we think I really need to do this?
 
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Old Jul 3, 2012 | 02:46 PM
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From: NE Iowa JD Country
Originally Posted by knuckle66
So today I cleaned the MAF and the TB. I didn't need to replace the K&N because that filter is no longer in there. It has a brand new one in it already. So I just cleaned everything up really good beause the basket and hoses were nasty.

The TB was horrible also. The intake is just as bad. It's covered in this thick oilly mess. I cleaned as much as I could. What's that stuff you can buy to clean that with? Also what is that second sensor after the MAF?

Someone also told me to reset the pcm by removing the negitave cable after I cleaned the TB. Do I need to do this?

While I'm throwing the kitchen sink at this what else should I do? I haven't looked at the fuel filter. Do we think I really need to do this?
Sounds like the K&N was over oiled previously way too much and that oil has migrated through out the duct work to the Throttle body...maybe beyond.

any parts store will have cleaner for MAF sensors. The next sensor I think is a Air Temp sensor??,,,if it is covered to, it's not sending accurate info either.

I'd still do the basic stuff right now....clean up the air inlet from filter to throttle body housing. (yes that means removing the throttle body housing and cleaning it with carb cleaner, there is 2 EGR ports in there that like to get carboned up).. Many do this a regular maintenance. Replace the PCV and fuel filter. This way you can gauge what has done the most to improve things.

then next month change the plugs....the month after that change the O2 sensors. Like mentioned earlier, This way you can gauge what has done the most to improve things. AND it won't cost so much at once.
 

Last edited by enriched&beyound; Jul 3, 2012 at 02:48 PM. Reason: more info
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Old Jul 3, 2012 | 04:28 PM
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Yeah I already cleaned the MAF with the MAF cleaner and I sprayed out everything else with the TB cleaner. What a mess that turned out to be. So for this round of repairs I'm going to see about replacing the fuel filter and the pvc valve and see what that does for me.

Next month I'll replace the spark plugs. Since I don't know when they were changed last if ever I know they need it. I don't have a miss so they are at least still working but only god knows how well.
 
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Old Jul 3, 2012 | 06:28 PM
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I also forgot to answer your question. On flat ground it wanted to shift out of O.D. and into passing gear it couldn't maintain any speed. And the speed I was trying to hold was 55-60. When I got to an interstate I was trying to hold 60-65, 70 on the down hill. I'm not trying to be a speed deamon with it when I'm hauling.
 
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Old Jul 4, 2012 | 06:52 AM
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From: NE Iowa JD Country
Originally Posted by knuckle66
Yeah I already cleaned the MAF with the MAF cleaner and I sprayed out everything else with the TB cleaner. What a mess that turned out to be. So for this round of repairs I'm going to see about replacing the fuel filter and the pvc valve and see what that does for me.

Next month I'll replace the spark plugs. Since I don't know when they were changed last if ever I know they need it. I don't have a miss so they are at least still working but only god knows how well.
sounds good...
Speaking of not answering questions....yeah removing the battery cable is a good idea...it'll reset the ECM to preset data. but itmight make it run rough at first...say the 1st 20-50 miles

The suspicion is that it should run a bunch better with getting that all cleaned up and new PCV. AND if it was as bad as you say, it may have (probably) fouled the plugs SO if you can stand it , change the spark plugs, the sooner , the better. If you want to see how it runs for now, & do the butt test & do the gauging thing , it can't hurt.

Not scare you, just prepare you for the worst.....Now, how long do you think this mistreatment of over oiled air filter/intake was going on?? The longer it was, the more expensive it could get. If this was over a extended period of time it may have corrupted the catalytic convertors & possibly burnt valves. This why I suggest changing the O2 sensors as well....@ over 103K on them...they could have gone a bit longer, but with all that half burnt oil residue going out the exhaust, in all likelyhood, they'll be trashed too. & you may have to get a new MAF sensor
 
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Old Jul 4, 2012 | 01:06 PM
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Maybe the brakes sticking a little?
 
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Old Jul 4, 2012 | 02:45 PM
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what is the fuel pressure supposed to be? Not that it matters because I don't have an adaptor small enough to fit. Everything has now been replaced. It seems to be running a lot better now. I haven't taken it out on the interstate yet with the camper but I will.
 
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Old Jul 6, 2012 | 06:02 AM
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Originally Posted by knuckle66
what is the fuel pressure supposed to be? Not that it matters because I don't have an adaptor small enough to fit. Everything has now been replaced. It seems to be running a lot better now. I haven't taken it out on the interstate yet with the camper but I will.
Thinking fuel pressure should be above 30psi.

glad to hear that it is running better
 
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Old Jul 6, 2012 | 10:21 AM
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So I've been on the interstate. I'm no longer trying to drive this in OD and it's just in towing mode. I do have more power than I did before but the plugs need replaced.
 
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