Running rich, bogging bad
06-22-2016, 02:29 PM
#1
Running rich, bogging bad
2001 Screw 4x4 with 5.4.
Engine rebuilt last year, been back to them 8 times now for various stuff they broke or didn't do correctly the first time.
Now that summer is here, when I use my AC, the truck bogs down even worse than usual. Barely climb a hill, kick it into 2nd gear to climb a hill.
No codes, but my long term fuel trims are -16% on one bank and -14% on the other while driving.
They're both around -7% while idling.
I replaced fuel pump and regulator and I'm getting 45psi fuel pressure at idle.
I don't have cats.
Thought about leaky injectors, but it would have to be both banks with at least one leaking.
Air filter is new.
Mass airflow sensor is new.
Brand new plugs and cops installed at engine rebuild.
Getting about 13.5 MPG.
Vacuum gauge reads good, around 24 inhg at idle.
Not sure what else to look for from here. Heard some about return fuel line, but don't know which one it is.
I just have a hard time believing this truck is such a dog. I really want to keep it but it's a real chore driving it every day.
Does everyone else's 5.4 bog down and lack power? Am I expecting too much from the truck to pull its own weight up a hill without losing 5-10 miles per hour? The transmission doesn't slip going uphill, my RPMs actually drop 100-200 going uphill.
If I had low compression, wouldn't the vacuum gauge reflect this?
Just wanted to see if anyone had any helpful ideas. Thanks.
Engine rebuilt last year, been back to them 8 times now for various stuff they broke or didn't do correctly the first time.
Now that summer is here, when I use my AC, the truck bogs down even worse than usual. Barely climb a hill, kick it into 2nd gear to climb a hill.
No codes, but my long term fuel trims are -16% on one bank and -14% on the other while driving.
They're both around -7% while idling.
I replaced fuel pump and regulator and I'm getting 45psi fuel pressure at idle.
I don't have cats.
Thought about leaky injectors, but it would have to be both banks with at least one leaking.
Air filter is new.
Mass airflow sensor is new.
Brand new plugs and cops installed at engine rebuild.
Getting about 13.5 MPG.
Vacuum gauge reads good, around 24 inhg at idle.
Not sure what else to look for from here. Heard some about return fuel line, but don't know which one it is.
I just have a hard time believing this truck is such a dog. I really want to keep it but it's a real chore driving it every day.
Does everyone else's 5.4 bog down and lack power? Am I expecting too much from the truck to pull its own weight up a hill without losing 5-10 miles per hour? The transmission doesn't slip going uphill, my RPMs actually drop 100-200 going uphill.
If I had low compression, wouldn't the vacuum gauge reflect this?
Just wanted to see if anyone had any helpful ideas. Thanks.
Last edited by rusty1971; 06-22-2016 at 02:38 PM.
06-22-2016, 03:43 PM
#2
Senior Member
Perhaps the compressor is going out. That will rob power.
If your lower intake is missing the cover/silencer, the engine will sound like it's bogging. Can be pretty pronounced. Easy to forget to put back on during an engine swap.
Other than that, - I would never purchase a rebuild from anyone but Ford with one of these. They are difficult to get right, even well known remanufactures don't always get these right. Simple 2 valve, should be easy right ? I don't know what it is exactly, but many rebuild attempts don't turn out.
It's why I've recommended take-outs vs remans over the years. Anyway, the 5fours have a flat spot at mid-range. If something isn't right with the PCV valve, plugs or MAF, it seems the mid range feels it more than anything.
Also, aged coils and injectors will show their age with time. I updated coils and injectors at the same time at 165,000 miles and the truck went from feeling like a heavy slug to feeling quick and responsive. I had no misfires at the time, seemed to be running okay. Just thought it was a good idea to update those. Once I changed them at that point in time, it was absolutely a night and day difference.
Make sure your up to par on maintenance. The correct maintenance parts matter quite a bit ie, the right brand of plugs and PCV valve. These engine are picky. Follow that owners manual since it can be crucial when maintaining her.
If your lower intake is missing the cover/silencer, the engine will sound like it's bogging. Can be pretty pronounced. Easy to forget to put back on during an engine swap.
Other than that, - I would never purchase a rebuild from anyone but Ford with one of these. They are difficult to get right, even well known remanufactures don't always get these right. Simple 2 valve, should be easy right ? I don't know what it is exactly, but many rebuild attempts don't turn out.
It's why I've recommended take-outs vs remans over the years. Anyway, the 5fours have a flat spot at mid-range. If something isn't right with the PCV valve, plugs or MAF, it seems the mid range feels it more than anything.
Also, aged coils and injectors will show their age with time. I updated coils and injectors at the same time at 165,000 miles and the truck went from feeling like a heavy slug to feeling quick and responsive. I had no misfires at the time, seemed to be running okay. Just thought it was a good idea to update those. Once I changed them at that point in time, it was absolutely a night and day difference.
Make sure your up to par on maintenance. The correct maintenance parts matter quite a bit ie, the right brand of plugs and PCV valve. These engine are picky. Follow that owners manual since it can be crucial when maintaining her.
06-22-2016, 03:53 PM
#3
Where is the lower intake cover? Is it something that can be seen by looking under the hood?
Also I've noticed the compressor kicking in and out fairly quickly.
Also I've noticed the compressor kicking in and out fairly quickly.
Perhaps the compressor is going out. That will rob power.
If your lower intake is missing the cover/silencer, the engine will sound like it's bogging. Can be pretty pronounced. Easy to forget to put back on during an engine swap.
Other than that, - I would never purchase a rebuild from anyone but Ford with one of these. They are difficult to get right, even well known remanufactures don't always get these right. Simple 2 valve, should be easy right ? I don't know what it is exactly, but many rebuild attempts don't turn out.
It's why I've recommended take-outs vs remans over the years. Anyway, the 5fours have a flat spot at mid-range. If something isn't right with the PCV valve, plugs or MAF, it seems the mid range feels it more than anything.
Also, aged coils and injectors will show their age with time. I updated coils and injectors at the same time at 165,000 miles and the truck went from feeling like a heavy slug to feeling quick and responsive. I had no misfires at the time, seemed to be running okay. Just thought it was a good idea to update those. Once I changed them at that point in time, it was absolutely a night and day difference.
Make sure your up to par on maintenance. The correct maintenance parts matter quite a bit ie, the right brand of plugs and PCV valve. These engine are picky. Follow that owners manual since it can be crucial when maintaining her.
If your lower intake is missing the cover/silencer, the engine will sound like it's bogging. Can be pretty pronounced. Easy to forget to put back on during an engine swap.
Other than that, - I would never purchase a rebuild from anyone but Ford with one of these. They are difficult to get right, even well known remanufactures don't always get these right. Simple 2 valve, should be easy right ? I don't know what it is exactly, but many rebuild attempts don't turn out.
It's why I've recommended take-outs vs remans over the years. Anyway, the 5fours have a flat spot at mid-range. If something isn't right with the PCV valve, plugs or MAF, it seems the mid range feels it more than anything.
Also, aged coils and injectors will show their age with time. I updated coils and injectors at the same time at 165,000 miles and the truck went from feeling like a heavy slug to feeling quick and responsive. I had no misfires at the time, seemed to be running okay. Just thought it was a good idea to update those. Once I changed them at that point in time, it was absolutely a night and day difference.
Make sure your up to par on maintenance. The correct maintenance parts matter quite a bit ie, the right brand of plugs and PCV valve. These engine are picky. Follow that owners manual since it can be crucial when maintaining her.
06-22-2016, 04:15 PM
#4
Senior Member
EDIT, - not even a thanks.
Last edited by Jbrew; 06-24-2016 at 05:59 PM.
06-22-2016, 11:51 PM
#5
Senior Member
Getting about 13.5 MPG.
Vacuum gauge reads good, around 24 inhg at idle.
24# at idle? Are you sure?
Engine at idle should read steady 15 to 20 in Hg.
Vacuum gauge reads good, around 24 inhg at idle.
24# at idle? Are you sure?
Engine at idle should read steady 15 to 20 in Hg.
Last edited by akdoggie; 06-22-2016 at 11:53 PM.
06-23-2016, 12:01 AM
#6
Senior Member
06-24-2016, 04:19 PM
#7
It wasn't too bad low.
Now, when I'm going down the road around 60mph and its in overdrive, every time to compressor kicks in, it downshifts the truck and revs the engine. When the compressor kicks out, it goes back into overdrive and the RPMs go back down. Wth???
Trending Topics
06-24-2016, 08:43 PM
#8
Senior Member
2001 Screw 4x4 with 5.4.
Now that summer is here, when I use my AC, the truck bogs down even worse than usual. Barely climb a hill, kick it into 2nd gear to climb a hill.
I just have a hard time believing this truck is such a dog. I really want to keep it but it's a real chore driving it every day.
Does everyone else's 5.4 bog down and lack power? Am I expecting too much from the truck to pull its own weight up a hill without losing 5-10 miles per hour? The transmission doesn't slip going uphill, my RPMs actually drop 100-200 going uphill.
If I had low compression, wouldn't the vacuum gauge reflect this?
Just wanted to see if anyone had any helpful ideas. Thanks.
Now that summer is here, when I use my AC, the truck bogs down even worse than usual. Barely climb a hill, kick it into 2nd gear to climb a hill.
I just have a hard time believing this truck is such a dog. I really want to keep it but it's a real chore driving it every day.
Does everyone else's 5.4 bog down and lack power? Am I expecting too much from the truck to pull its own weight up a hill without losing 5-10 miles per hour? The transmission doesn't slip going uphill, my RPMs actually drop 100-200 going uphill.
If I had low compression, wouldn't the vacuum gauge reflect this?
Just wanted to see if anyone had any helpful ideas. Thanks.
4.2 V6 Overhead Valve (1 Camshaft = Short Timing Chain)
Bore - 3.81 in (96.8mm)
Stroke - 3.74 in (95mm)
Injector 21lbs/hr (Black)
Wheel - 16" Aluminum alloy
4.6 V8 Overhead Cam
Bore - 3.55 in (90.2 mm)
Stroke - 3.54 in (90mm)
Injector 19lbs/hr (Orange)
Wheel- 17" Steel
5.4 V8 Overhead Cam
Bore - 3.55 in (90.2mm)
Stroke - 4.16 in (105.8mm)
Injector 19lbs/hr (Orange)
Wheel - 17" Steel
24 inches of mercury at idle??
REALLY???
Last edited by w0lvez; 06-24-2016 at 09:00 PM.
06-24-2016, 09:24 PM
#9
Senior Member
Here we go again. w0lves hasn't been getting enough attention lately so he decides to vomit on a thread. Please refrain from feeding this goof!
06-24-2016, 09:51 PM
#10
The vacuum was wrong as I was going off of memory. I'm hovering steady at 20 at idle.