Ford Powerstroke Diesel Forum banner

1 - 20 of 30 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter #1 (Edited)
I have posted a few times recently seeking input with this ongoing issue of no power when towing my puny 5,000 lb travel trailer- still having problems..
just to recap- I bought this truck brand new in 2002- it currently has 112,000 miles on it- it is an absolute creampuff and I have taken exceptional care of it and it is impeccably serviced and maintained. I had the transmission go out at 73,000 miles and a new transmission was installed by Ford....then that transmission started to slip at 98,000 and was replaced again(still under warranty)….I have towed periodically with it in the past and know what a beast it can be when running right but haven't had the need to tow anything up until the past few years when I got this 5000 lb travel trailer- it started last fall when towing in the mountains I noticed it was dogging going uphill(Overdrive OFF)....I would be at 55 or 60 mph and when I would ask for more the pedal would push to the floor without any further response, it wouldn't downshift into a lower gear and wouldn't go any faster- no dashboard lights...it seemed to be running fine, not rough, no skipping or missing- temp gauges were normal-Without a load it drove beautifully- took it to Ford - they scanned it and everything checked out- but went with first idea based on the notorious issue that many other people seemed to have- had gas tank dropped and pickup foot replaced on sending unit(starting to fall apart) and strainers checked and cleaned, everything was clean- gas tank is plastic mid-ship tank was totally clean, no water algae or sludge- had screen in fuel pressure regulator cleaned and fuel lines blown out- fuel filter changed and completely checked for exhaust and boost leaks(no leaks). Went home hooked up my travel trailer, no improvement on power issue going uphill....brought back to FORD, speculated that perhaps there was a clog IN sending unit from plastic falling apart from original pickup screen that was replaced...then they replaced the entire sending unit- scanned again while driving(no trailer) everything was normal, no codes- went home hooked up travel trailer still had no power going uphill, my foot was on the floor at 55 mph and 2200 rpm's- overdrive off(always off when towing)...Called Ford they told me to bring BOTH the truck and trailer in so they can witness the no power issue while I drive the travel trailer uphill, tech sat in passenger seat with scanner hooked up sitting in his lap- everything checked out OK- fuel pump seemed to be fine- all was normal- I had normal boost but he witnessed the lack of power- 55mph and my foot was on the floor....he was scratching his head and commented that it seems like a fuel delivery issue....I brought the truck home dropped the travel trailer and brought the truck back to Ford and left it there- everyone is scratching their heads- I have reached out on a few different forums and watched a bunch of video's on YouTube trying to find answers....I have followed all the suggestions that everyone has offered so far and nothing has improved....it has been on the scanner while driving with and without the trailer and everything shows "Normal"....at this point I am out of ideas...and the guys at Ford will be starting a witch hunt on Monday morning when they start looking at my truck- I could start "Throwing Parts" at it...but have no idea where to begin and of course my funds are tight just like anyone else....
Don't know what to do next and am completely frustrated-
Sorry for the long winded post- but wanted everyone to know what has already been done- Would appreciate any input.
 

·
Registered
Joined
·
43 Posts
I suggest checking fuel pressure if you haven't already. Should be a minimum of 55psi I believe.

Sent from my Pixel 3 using Tapatalk
 

·
Registered
Joined
·
448 Posts
I have posted a few times recently seeking input with this ongoing issue of no power when towing my puny 5,000 lb travel trailer- still having problems..
just to recap- I bought this truck brand new in 2002- it currently has 112,000 miles on it- it is an absolute creampuff and I have taken exceptional care of it and it is impeccably serviced and maintained. I had the transmission go out at 73,000 miles and a new transmission was installed by Ford....then that transmission started to slip at 98,000 and was replaced again(still under warranty)….I have towed periodically with it in the past and know what a beast it can be when running right but haven't had the need to tow anything up until the past few years when I got this 5000 lb travel trailer- it started last fall when towing in the mountains I noticed it was dogging going uphill....I would be at 55 or 60 mph and when I would ask for more the pedal would push to the floor without any further response, it wouldn't downshift into a lower gear and wouldn't go any faster- no dashboard lights...it seemed to be running fine, not rough, no skipping or missing- temp gauges were normal-Without a load it drove beautifully- took it to Ford - they scanned it and everything checked out- but went with first idea based on the notorious issue that many other people seemed to have- had gas tank dropped and pickup foot replaced on sending unit(starting to fall apart) and strainers checked and cleaned, everything was clean- gas tank is plastic mid-ship tank was totally clean, no water algae or sludge- had screen in fuel pressure regulator cleaned and fuel lines blown out- fuel filter changed and completely checked for exhaust and boost leaks(no leaks). Went home hooked up my travel trailer, no improvement on power issue going uphill....brought back to FORD, speculated that perhaps there was a clog IN sending unit from plastic falling apart from original pickup screen that was replaced...then they replaced the entire sending unit- scanned again while driving(no trailer) everything was normal, no codes- went home hooked up travel trailer still had no power going uphill, my foot was on the floor at 55 mph and 2200 rpm's- overdrive off(always off when towing)...Called Ford they told me to bring BOTH the truck and trailer in so they can witness the no power issue while I drive the travel trailer uphill, tech sat in passenger seat with scanner hooked up sitting in his lap- everything checked out OK- fuel pump seemed to be fine- all was normal- I had normal boost but he witnessed the lack of power- 55mph and my foot was on the floor....he was scratching his head and commented that it seems like a fuel delivery issue....I brought the truck home dropped the travel trailer and brought the truck back to Ford and left it there- everyone is scratching their heads- I have reached out on a few different forums and watched a bunch of video's on YouTube trying to find answers....I have followed all the suggestions that everyone has offered so far and nothing has improved....it has been on the scanner while driving with and without the trailer and everything shows "Normal"....at this point I am out of ideas...and the guys at Ford will be starting a witch hunt on Monday morning when they start looking at my truck- I could start "Throwing Parts" at it...but have no idea where to begin and of course my funds are tight just like anyone else....
Don't know what to do next and am completely frustrated- Would appreciate any input.
I would hope they monitored things like injectors, boost, etc. When you mash it to the floor going up a hill shouldn't it downshift?

I'm not skilled enough to offer advice but I know when I go to the floor it downshifts out of over drive.

No matter what, update the thread here because it may help someone else out in the future.

Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
36 Posts
Discussion Starter #4
I would hope they monitored things like injectors, boost, etc. When you mash it to the floor going up a hill shouldn't it downshift?

I'm not skilled enough to offer advice but I know when I go to the floor it downshifts out of over drive.

No matter what, update the thread here because it may help someone else out in the future.

Sent from my SM-N960U using Tapatalk
Yes, exactly....it SHOULD downshift....but doesn't....I am sure that they checked all things relevant….this is the Ford dealer....will update the thread as I make progress...thanks!!
 

·
Registered
Joined
·
448 Posts
Yes, exactly....it SHOULD downshift....but doesn't....I am sure that they checked all things relevant….this is the Ford dealer....will update the thread as I make progress...thanks!!
My point was maybe it's transmission related. I don't know what causes the downshift. It could be computer controlled or a cable. You should try with the OD switched off and see if it seems normal going up at that point. If so, then you know it's a downshift problem. That may help the Ford techs. Hopefully the tech is older. Some of the younger guys haven't worked on the order trucks.

Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
615 Posts
She’s already saying her foot is on the floor at 55-60 mph with OD off. It shouldn’t need to downshift at that speed in 3rd gear lockup even with it to the floor. 2nd gear would be way too high of an rpm at that speed

They need to do more than just scan the pcm, 7.3s can have issues that fly under the computers radar. They need to look at things like fuel pressure, exhaust leaks (up pipes are common) and/or boost leaks, watch boost pressure on a mechanical gauge, etc. If all checks out they could do a compression test to see if the engine is healthy. Do you have lots of blow by?

What are your ICP and IPR values with the pedal on the floor towing uphill?


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
448 Posts
She’s already saying her foot is on the floor at 55-60 mph with OD off. It shouldn’t need to downshift at that speed in 3rd gear lockup even with it to the floor. 2nd gear would be way too high of an rpm at that speed

They need to do more than just scan the pcm, 7.3s can have issues that fly under the computers radar. They need to look at things like fuel pressure, exhaust leaks (up pipes are common) and/or boost leaks, watch boost pressure on a mechanical gauge, etc. If all checks out they could do a compression test to see if the engine is healthy. Do you have lots of blow by?

What are your ICP and IPR values with the pedal on the floor towing uphill?


Sent from my iPhone using Tapatalk
I missed that od was off. Maybe it's actually in OD and not downshifting?

Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
36 Posts
Discussion Starter #8
She’s already saying her foot is on the floor at 55-60 mph with OD off. It shouldn’t need to downshift at that speed in 3rd gear lockup even with it to the floor. 2nd gear would be way too high of an rpm at that speed

They need to do more than just scan the pcm, 7.3s can have issues that fly under the computers radar. They need to look at things like fuel pressure, exhaust leaks (up pipes are common) and/or boost leaks, watch boost pressure on a mechanical gauge, etc. If all checks out they could do a compression test to see if the engine is healthy. Do you have lots of blow by?

What are your ICP and IPR values with the pedal on the floor towing uphill?


Sent from my iPhone using Tapatalk
I am super in tune with how my truck runs....and how it tows a trailer- and although I am no mechanic and have no clue as to things like gear lockup, I can tell you thet when pulling my travel trailer I always had TONs of pedal left to spare when towing uphill....and the RPM's would sometimes jump up and the truck would ROAR with power as the speed increased....that doesn't happen currently it struggles to get to 3000 RPM's....even going up on an "Onramp" onto the interstate it dogs....no power....
I appreciate your input- they did check for exhaust leaks and boost leaks but I am certain that since they have the truck there for an indefinite period of time they will be taking a closer look....yes, they did say that up-pipe leaks are common and although they looked, again, I am sure they will be getting in there a little deeper when the engine is cool- I am in southern AZ where the temps have been 102+ for the past 3 weeks and my truck was always scalding hot from driving the previous times I was in there....I am sorry, but I couldn't tell you what the ICP and IPR pressures were while driving- but the mechanic said they were within normal ranges....not sure what I am looking to hear- I guess maybe I was hoping someone else had a similar "Phantom" problem and they could tell me what route they went to get it fixed....again, thanks so much for the input!!
 

·
Registered
Joined
·
36 Posts
Discussion Starter #11
Have they check for plugged exhaust may be something in the muffler that is plugging up under high boost presser.
Thanks you very much for saying that....that was one of my concerns...last week I laid in the carport with a ratchet and tapped on the entire length of the exhaust hoping that maybe I would hear some sort of "Inconsistancy"....perhaps indicating some sort of restriction- my truck came from the factory with NO catalytic converter- so there is not much to the exhaust except for the muffler- and since this is AZ and I don't do any off road crazy stuff it is all in excellent shape....but yes, that was the last thought I left them with.....PLEASE check for exhaust blockages....and if the up pipes end up being cracked then I am going to have them replace the whole system with a 4" straight pipe exhaust....sigh...praying it could actually be something that simple....
 

·
Registered
Joined
·
36 Posts
Discussion Starter #12
How's the blowby? Could it be a tired engine? Plugged air or fuel filter?

Sent from my SM-N960U using Tapatalk
it only has 112,000 miles...I mentioned in my post that I just changed the fuel filter...I installed a Donaldson Blue 6637 air filter from Riff Raff in May(last month)….other than the air filter it is BONE stock.....no mods....nothing..
 

·
Registered
Joined
·
36 Posts
Discussion Starter #13
it only has 112,000 miles...I mentioned in my post that I just changed the fuel filter...I installed a Donaldson Blue 6637 air filter from Riff Raff in May(last month)….other than the air filter it is BONE stock.....no mods....nothing..
No Blow by....pipes clean....
 

·
Registered
Joined
·
448 Posts
it only has 112,000 miles...I mentioned in my post that I just changed the fuel filter...I installed a Donaldson Blue 6637 air filter from Riff Raff in May(last month)….other than the air filter it is BONE stock.....no mods....nothing..
Not saying that this is it but did it start after the new filter? I've had trouble with filters a bunch of times. Usually not sealing and spurting diesel everywhere but one caused it to fun poorly so I only get expensive filters. Baldwin I think.

Sent from my SM-N960U using Tapatalk
 

·
Registered
Joined
·
40 Posts
I was glad to see a suggestion for plugged exhaust.

Restricted exhaust results in boost dropping off too. If the air can't get out, it can't get in either. Intake and exhaust flows will equalize. Boost pressure will be less than ,maximum. << Hint for restricted exhaust on wastegated turbo diesels.
 

·
Registered
Joined
·
138 Posts
My 2000 F-350 acted a lot like this when I first got it too. Uphill, manually pulled out of OD, mash the pedal, and it would not downshift nor would I have much power. I think the computer monitors how much power the engine is actually making and determines how it will shift the trans.

Anyway, my truck ended up having some boost leaks. One of the clamps was actually loose on the intercooler, and you could see the boost leak at the spider where it meets the boots to the heads (you could see how the boost was pushing the oily dirt away). I check my clamps now at every oil change just to be sure. My exhaust has now been changed as well; nothing was plugged necessarily but the muffler had something come loose internally which made quite a racket. It's now got a Magnaflow "cat back" system (although, like you I have no cat, but here in CA that's all I could get). I cleaned out the Exhaust Back Pressure tube as well, and have also swapped out the compressor wheel with a billet version similar to the WW2. Now, when mashing the pedal the truck will downshift on it's own. I don't typically hit 3,000 rpm but I'm sure it would easily hit that mark... Pulling a 12% grade yesterday in the heat unloaded (I'm at 8,000 pounds empty) 2nd gear held no problem, locked, at 2500 rpm with plenty of pedal.

You should be able to check the up pipes for sooty marks pretty easily from under the truck with the hood open. Definitely want those to be sealed up; another area to inspect is the exhaust side of the turbo. My bolts on the exhaust snail have a tendency to come loose, thus loosing boost pressure.

Have you considered one of those bluetooth OBD-II devices? Using that and an app like Torque can give you a lot of info while the truck is running. Just don't let it do a system test while it's running.

Clay
 

·
Registered
Joined
·
3 Posts
I have posted a few times recently seeking input with this ongoing issue of no power when towing my puny 5,000 lb travel trailer- still having problems..
just to recap- I bought this truck brand new in 2002- it currently has 112,000 miles on it- it is an absolute creampuff and I have taken exceptional care of it and it is impeccably serviced and maintained. I had the transmission go out at 73,000 miles and a new transmission was installed by Ford....then that transmission started to slip at 98,000 and was replaced again(still under warranty)….I have towed periodically with it in the past and know what a beast it can be when running right but haven't had the need to tow anything up until the past few years when I got this 5000 lb travel trailer- it started last fall when towing in the mountains I noticed it was dogging going uphill(Overdrive OFF)....I would be at 55 or 60 mph and when I would ask for more the pedal would push to the floor without any further response, it wouldn't downshift into a lower gear and wouldn't go any faster- no dashboard lights...it seemed to be running fine, not rough, no skipping or missing- temp gauges were normal-Without a load it drove beautifully- took it to Ford - they scanned it and everything checked out- but went with first idea based on the notorious issue that many other people seemed to have- had gas tank dropped and pickup foot replaced on sending unit(starting to fall apart) and strainers checked and cleaned, everything was clean- gas tank is plastic mid-ship tank was totally clean, no water algae or sludge- had screen in fuel pressure regulator cleaned and fuel lines blown out- fuel filter changed and completely checked for exhaust and boost leaks(no leaks). Went home hooked up my travel trailer, no improvement on power issue going uphill....brought back to FORD, speculated that perhaps there was a clog IN sending unit from plastic falling apart from original pickup screen that was replaced...then they replaced the entire sending unit- scanned again while driving(no trailer) everything was normal, no codes- went home hooked up travel trailer still had no power going uphill, my foot was on the floor at 55 mph and 2200 rpm's- overdrive off(always off when towing)...Called Ford they told me to bring BOTH the truck and trailer in so they can witness the no power issue while I drive the travel trailer uphill, tech sat in passenger seat with scanner hooked up sitting in his lap- everything checked out OK- fuel pump seemed to be fine- all was normal- I had normal boost but he witnessed the lack of power- 55mph and my foot was on the floor....he was scratching his head and commented that it seems like a fuel delivery issue....I brought the truck home dropped the travel trailer and brought the truck back to Ford and left it there- everyone is scratching their heads- I have reached out on a few different forums and watched a bunch of video's on YouTube trying to find answers....I have followed all the suggestions that everyone has offered so far and nothing has improved....it has been on the scanner while driving with and without the trailer and everything shows "Normal"....at this point I am out of ideas...and the guys at Ford will be starting a witch hunt on Monday morning when they start looking at my truck- I could start "Throwing Parts" at it...but have no idea where to begin and of course my funds are tight just like anyone else....
Don't know what to do next and am completely frustrated-
Sorry for the long winded post- but wanted everyone to know what has already been done- Would appreciate any input.
I had the same problem with my 2001 7.3, turned out the (MAP) Manifold Absolute Pressure sensor hose connection was cracked. It’s connected by a 2’+ section of hose that had shrank over the years. It’s mounted on the left-hand side of the firewall. Without it sensing a difference in pressure as you execrate Turbo boost is almost non-existent. Forgot to mention a scanner wont detect the problem because electronically it’s in working order.
MAP.jpg
 
1 - 20 of 30 Posts
Top