Power Comes And Goes
#16
07-30-2008, 08:53 PM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
Still no check engine light? No check engine light. How bad did the oil look, and what did the inside of the fuel tank look like? The oil didn't look too bad, it was black but nothing extreme. The fuel tank did have some residue but we got it cleaned up pretty good. Getting some live data from a scanner would be helpful. I have put a generic code reader on it but don't have a scanner. You may need to hook up a fuel pressure guage since your problems seem to happen at speed. It idles rough when it is acting up.
When it's running rough. If you pull over do you get a smooth idle, or is it still rough? When it is doing it's thing, it is through the whole rpm range, sometimes parked it won't make 2000 rpm. If it smooths out at lower rpm's I'd suspect a fuel issue. If it's still rough you may want to check the UVCH (under valve cover harness) wiring. That is possible but it seems that sitting for a long while wouldn't have created that problem although logic doesn't always work with mechanical stuff. Have you watched the engine temps to see if the problem only shows up after the engine is warmed up? It can be cold or hot, doesn't seem to make much difference. If the engine runs good cold and poorly when hot we may need to look at oil / IPR issues. What type of oil did you use? Rotella T
The UVCH wiring can be checked with an OHM meter. Look on the inboard side of each head for a rectangular plug with 9 wires in it. Those are the ones you want to test.
The connector at the valve cover has a plug on both the inside and the outside. The one on the inside is usually the one that comes loose. You can disconnect the outside plug and ohm the wires for resistance to determine which side needs to come off. The valve cover gasket is re-usable.
The 9-pin plug is wired as follows:
G G I I C I I G G
G=Glow Plug +
I = Injector +
C= Injector Common
The injectors fire with a 115VDC signal from the IDM. Do Not pierce the wires to test.
Test between "I" and "C" to test the injectors, should be less than 5.0 Ohms.
To check glow plugs Test between "G" and battery ground. Should be between 0.6 and 2.0 Ohms
When it's running rough. If you pull over do you get a smooth idle, or is it still rough? When it is doing it's thing, it is through the whole rpm range, sometimes parked it won't make 2000 rpm. If it smooths out at lower rpm's I'd suspect a fuel issue. If it's still rough you may want to check the UVCH (under valve cover harness) wiring. That is possible but it seems that sitting for a long while wouldn't have created that problem although logic doesn't always work with mechanical stuff. Have you watched the engine temps to see if the problem only shows up after the engine is warmed up? It can be cold or hot, doesn't seem to make much difference. If the engine runs good cold and poorly when hot we may need to look at oil / IPR issues. What type of oil did you use? Rotella T
The UVCH wiring can be checked with an OHM meter. Look on the inboard side of each head for a rectangular plug with 9 wires in it. Those are the ones you want to test.
The connector at the valve cover has a plug on both the inside and the outside. The one on the inside is usually the one that comes loose. You can disconnect the outside plug and ohm the wires for resistance to determine which side needs to come off. The valve cover gasket is re-usable.
The 9-pin plug is wired as follows:
G G I I C I I G G
G=Glow Plug +
I = Injector +
C= Injector Common
The injectors fire with a 115VDC signal from the IDM. Do Not pierce the wires to test.
Test between "I" and "C" to test the injectors, should be less than 5.0 Ohms.
To check glow plugs Test between "G" and battery ground. Should be between 0.6 and 2.0 Ohms
Thanks again for all your input
Ken
#17
07-30-2008, 08:54 PM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
#18
07-30-2008, 08:57 PM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
#19
07-30-2008, 10:24 PM
Post Fiend
Join Date: Feb 2006
Location: Middle Tennessee
Posts: 11,892
Likes: 0
Received 0 Likes
on
0 Posts
Hmm, 161miles/3hours. That is just a bit too far for me with fuel prices. Anyone closer? Get a fuel pressure gauge on that thing and run the usual tests. I still say fuel problem. Anyone closer with a scanner/AE?
#20
08-02-2008, 09:31 PM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
Ok, I have a little more to add... I have drove the truck a few more times just to see if there was any type of pattern. It seems that as long as I take it easy on the throttle, it keeps up pretty well with just a little miss now and then. When getting on the throttle hard is when it is more apt to fall on it's face. I drove it for about 20 miles in the past couple of nights without it loosing all power but when I got close to the house I mashed on it and then it started losing it again.
I was wondering if the fuel pump on the frame rail could be weak? I am thinking it is for volume, is that right? Is it possible that it is weak and can't keep up with the higher volume of fuel when I mash on it. Wouldn't that give the feeling of a stopped up filter if that pump can't keep up? When the truck has died while driving it, the pump on the frame rail has always been running. I don't know if that is just a coincidence or if it is pointing toward starving for fuel. What do you guys think?
I haven't had the time to check on the 9 pin connector yet to rule out the wiring harness. Will try to get that done next week.
Thanks,
Ken
I was wondering if the fuel pump on the frame rail could be weak? I am thinking it is for volume, is that right? Is it possible that it is weak and can't keep up with the higher volume of fuel when I mash on it. Wouldn't that give the feeling of a stopped up filter if that pump can't keep up? When the truck has died while driving it, the pump on the frame rail has always been running. I don't know if that is just a coincidence or if it is pointing toward starving for fuel. What do you guys think?
I haven't had the time to check on the 9 pin connector yet to rule out the wiring harness. Will try to get that done next week.
Thanks,
Ken
#21
08-02-2008, 09:44 PM
The fuel pump always runs. It's electric so it's an on/off type pump. Excess fuel not needed by the engine is returned to the tank through the FPR. Is there any sings of junk in the bottom of the fuel bowl? Maybe some debris is keeping the FPR open?
I still think getting a fuel pressure guage on there, and monitoring things at WOT (including live data) would help you.
I still think getting a fuel pressure guage on there, and monitoring things at WOT (including live data) would help you.
#22
08-03-2008, 09:18 AM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
Is there any sings of junk in the bottom of the fuel bowl? When I changed the fuel filter the other day, there was some residue in the filter bowl but I cleaned all of it out. You say that the fuel pump is on or off... is that just when the key is on or off or is there something else that controls that?
I still think getting a fuel pressure guage on there, and monitoring things at WOT (including live data) would help you.
I still think getting a fuel pressure guage on there, and monitoring things at WOT (including live data) would help you.
Thanks,
Ken
#23
08-03-2008, 12:04 PM
The fuel pump comes on when the key is turned on. If you don't start the truck the PCM will turn the fuel pump off after about 20 seconds. Start the truck and it stays on. Any extra fuel the injectors don't need is sent back into the tank through the FPR (fuel pressure regulator). The FPR has a spring and poppet valve that opens to return the excess fuel to the tank. If you've got debris stuck in there it may account for low fuel pressure.
When you cleaned the fuel tank how dirty was it? If there was junk inside there, did you address the screens in the pick up tube? No signs of oil in the bottom of the fuel bowl, right? Sure wish we could find someone close by with a scanner to take a closer look at things.
When you cleaned the fuel tank how dirty was it? If there was junk inside there, did you address the screens in the pick up tube? No signs of oil in the bottom of the fuel bowl, right? Sure wish we could find someone close by with a scanner to take a closer look at things.
#24
08-03-2008, 09:33 PM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
The fuel pump comes on when the key is turned on. If you don't start the truck the PCM will turn the fuel pump off after about 20 seconds. Start the truck and it stays on. Any extra fuel the injectors don't need is sent back into the tank through the FPR (fuel pressure regulator). The FPR has a spring and poppet valve that opens to return the excess fuel to the tank. If you've got debris stuck in there it may account for low fuel pressure.
When you cleaned the fuel tank how dirty was it? If there was junk inside there, did you address the screens in the pick up tube? It wasn't what I would call real dirty, probably about normal to a little dirty. No signs of oil in the bottom of the fuel bowl, right? Correct, no signs of oil in the fuel bowl. Sure wish we could find someone close by with a scanner to take a closer look at things.
When you cleaned the fuel tank how dirty was it? If there was junk inside there, did you address the screens in the pick up tube? It wasn't what I would call real dirty, probably about normal to a little dirty. No signs of oil in the bottom of the fuel bowl, right? Correct, no signs of oil in the fuel bowl. Sure wish we could find someone close by with a scanner to take a closer look at things.
).For the most part, I am patient enough to get to the bottom of things rather than just giving up and passing the problem on to someone else. Working out these type of problems is much easier now than it was in the dark ages before everyone had a computer and forums like this one where years and years worth of experience is available by just reading some topics.
350, thanks for all of your help so far and I am sure I will be getting more before this truck is going strong again.
I would offer to meet you half way or even further but I wouldn't be able to tell you when since I wouldn't know if I could run 50 mph or 70 or 10
Ken
#25
08-03-2008, 11:45 PM
Post Fiend
Join Date: Feb 2006
Location: Middle Tennessee
Posts: 11,892
Likes: 0
Received 0 Likes
on
0 Posts
#26
08-04-2008, 07:34 AM
Hotshot
I'm 150 miles from him, but I don't have a scanner or fuel pressure gauge. I'm 15 miles southeast of Cincinnati, OH. There is a guy up in this area that knows these powerstrokes like the back of his hand. He's very reasonable on price. He could even come down and haul the ambulance back up here if necessary. The folks at All-State Ford in Louisville know their stuff too, but it will cost you if you go that route.
#27
08-04-2008, 11:55 AM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
I spent a little time with the truck this morning and when it fell on it's face, there was lots of light bluish colored smoke out of the tail pipe. Then it picked back up on power (not full power) with no excess smoke. It also did fall on it's face again with no excess smoke. While in park and giving it throttle, it would run up to about 2000 rpm with a very slight miss then as I applied more throttle it would bellow out the bluish smoke for a second or two with heavy missing then proceed to run on up in the rpm's without smoke. Almost like it was clearing out something or starving for enough fuel or something like that. It repeated this process most times while going through the throttle range but sometimes it would run through the whole range without smoke and hesitation.
Does any of that point to anything?
Thanks,
Ken
Does any of that point to anything?
Thanks,
Ken
#28
08-04-2008, 01:34 PM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
#29
08-06-2008, 12:02 PM
Join Date: Jul 2008
Posts: 18
Likes: 0
Received 0 Likes
on
0 Posts
Hello All,
I have pulled the omhs readings for the injectors and all 8 was less than spec which I am assuming that means the inside connectors a fastened and the injectors are good???
I am getting ready to pull the fuel filter off again to check for sediment and to make sure everything looks good there.
Anyone know anything else I should look at before closing back up and digging into the wallet to take to a shop?
Thanks,
Ken
I have pulled the omhs readings for the injectors and all 8 was less than spec which I am assuming that means the inside connectors a fastened and the injectors are good???
I am getting ready to pull the fuel filter off again to check for sediment and to make sure everything looks good there.
Anyone know anything else I should look at before closing back up and digging into the wallet to take to a shop?
Thanks,
Ken
#30
08-06-2008, 12:41 PM