Help Needed 7.3L mystery - F-Series & SuperDuty Diesel Forums

Pecoy · 12-12-2011, 10:09 AM

Needing some help with a little issue. This is my first time to post here and hoping to get a little advice/help. I have an '03 F-350 with the 7.3L and love the truck except for about the past month is has been giving me fits as far as dieing on me. It only occurs on the intial start up in the morning though. I was reading the post about the CPS failure that is typical in the 7.3L and it sounds a lot like that problem. The only thing is, my mechanic and I have already changed out the cam sensor. Is there something more? A little more of what it is doing: on the inital start up for the day, driving down the road it will lose power and die. Some days I can keep it running if I don't take my foot off the accelerator. After giving the truck a little time (30 seconds to one minute) it will crank up and run just fine the rest of the day. Some days it will throw a code and some days it will not have a code. Also, a lot of the times when it does this it sounds as if a fuse is trying to catch a connection in the fuse panel under the steering column. Thanks.

DaveBen · 12-12-2011, 10:22 AM

Pecoy. What code? These computer controlled engines give us a code, if we read at it.

Dave

Pecoy · 12-12-2011, 10:30 AM

That has been the real mystery too. The codes have been different almost every time. The only consistant code was a P3048 or P0348? I think that is what code it was, do not remember for sure. It was the back pressure code.

dpantazis · 12-12-2011, 11:56 AM

one step at a time.
1. start off with basic diagnostic techniques.

2. you mean the Exhaust Back Pressure control? Search for EBPV here and you will learn much about the valve. could be the tube is plugged. its cleanable.

Pecoy · 12-12-2011, 12:12 PM

We have ran all the diagostics, even running the Ford program. The only interesting part of that is when we ran that program, the Ford program read the truck as being a 2000 7.3L with a manual transmission. When we re-ran the program, at the intitial screen, we told it that the info that it was reading was not that truck that it was an '03. At that time it read the truck properly as an '03 with an automatic transmition. I bought this truck used and when we saw that we thought that a new computer had been installed. Still have not ruled that possiblity out either.

Yes the EBPV code is what keeps coming up. We thought that could be an issue too so took the pipe apart at the valve and it appears to operating correctly too. I do appreciate the info and I will look more into the EBPV. The part of that and all this is that is strange is that it will only happen on the intitial start up of the day. It does not matter how many start ups or even the temperature of the truck/engine after that intitial start up it will not happen again the rest of the day.

iracemine · 12-12-2011, 09:17 PM

OK a quick idea. when it dies and you try to start it up again right away to no avail, does the tachometer move?

Smoky · 12-12-2011, 09:36 PM

Just a SWAG, clean the battery cables and battery post to ensure good electrical connections?

Pecoy · 12-13-2011, 06:39 AM

Once it dies I have discovered that I can't immediately crank it back up. Have to wait 30 seconds to a minute and it will immediately crank. The first time this happened to me I did immediately try to crank it and if I remember correctly the tach did move. Now I have noticed once that when the truck first looses power the tach dropped immediately but popped right back up to where the RPM's were at before loosing power.

We did get a code one time about loose battery connections so the posts and cables have been cleaned up, checked, and tightened. That code has not reappeared again. This code also was not the first time this happened, more along the third time.

iracemine · 12-13-2011, 07:32 AM

Quote:

Originally Posted by Pecoy

Once it dies I have discovered that I can't immediately crank it back up. Have to wait 30 seconds to a minute and it will immediately crank. The first time this happened to me I did immediately try to crank it and if I remember correctly the tach did move. Now I have noticed once that when the truck first looses power the tach dropped immediately but popped right back up to where the RPM's were at before loosing power.

We did get a code one time about loose battery connections so the posts and cables have been cleaned up, checked, and tightened. That code has not reappeared again. This code also was not the first time this happened, more along the third time.

get another cps sensor and chuck it in there just to rule out a bad sensor. Bad new parts happens more than you think.

Pecoy · 12-13-2011, 07:47 AM

I will see about trying the new sensor also. The truck acted up again this morning and based on a lot of what I have read on here and from a lot of what everyone here has been indicating to me I am starting to lean more towards an issue with the EBPV or piping on it. This morning the check engine light kept flashing on and off, the truck never died, but as I was driving down the road the truck would have a slight "buck" as if it was not getting enough fuel or the engine was starved for air. Any thoughts?

12-12-2011, 10:09 AM	#1
Pecoy SDD Junior Member Join Date: Dec 2011 Location: Broken Arrow OK Posts: 7 Thanks: 0 Thanked 0 Times in 0 Posts	7.3L mystery Needing some help with a little issue. This is my first time to post here and hoping to get a little advice/help. I have an '03 F-350 with the 7.3L and love the truck except for about the past month is has been giving me fits as far as dieing on me. It only occurs on the intial start up in the morning though. I was reading the post about the CPS failure that is typical in the 7.3L and it sounds a lot like that problem. The only thing is, my mechanic and I have already changed out the cam sensor. Is there something more? A little more of what it is doing: on the inital start up for the day, driving down the road it will lose power and die. Some days I can keep it running if I don't take my foot off the accelerator. After giving the truck a little time (30 seconds to one minute) it will crank up and run just fine the rest of the day. Some days it will throw a code and some days it will not have a code. Also, a lot of the times when it does this it sounds as if a fuse is trying to catch a connection in the fuse panel under the steering column. Thanks.

12-12-2011, 10:22 AM	#2
DaveBen SDD Senior Member Join Date: May 2005 Location: Ukiah, California Posts: 7,869 Thanks: 127 Thanked 506 Times in 489 Posts	Pecoy. What code? These computer controlled engines give us a code, if we read at it. Dave __________________ 2004 F-350 Regular cab with 6.0, Torqshift, 4X4, and just about all of the rest of the options. I added Guages, Satellite Radio, Air Horns, and a coolant filter. Bilstein shocks. Battery Desulphater that really works. Installed Jimmi Jammers. Pictures here: http://community.webshots.com/user/dbennett48 Completely Stock. I had a Detroit Diesel 8V92TA in a KW dump truck in 1980. That sucker would put out 425 hp but would never out pull a CAT.

12-12-2011, 11:56 AM	#4
dpantazis #12 Join Date: Nov 2005 Location: under the cheddar curtain Posts: 1,802 Thanks: 8 Thanked 105 Times in 90 Posts View Photos By: dpantazis	one step at a time. 1. start off with basic diagnostic techniques. 2. you mean the Exhaust Back Pressure control? Search for EBPV here and you will learn much about the valve. could be the tube is plugged. its cleanable. __________________ SPECS:Y2K F250 SC LB 4WD Get Skype and call me for free!

12-12-2011, 09:17 PM	#6
iracemine black and tan Join Date: Dec 2006 Location: Cheese Curtain Posts: 914 Thanks: 46 Thanked 44 Times in 40 Posts	OK a quick idea. when it dies and you try to start it up again right away to no avail, does the tachometer move? __________________ coolant filter (dieselsite), CCV Mod (home made), 4" MBRP turbo back (dieselsite), turbo temp monitor (ISSPROdieselsite), DIY triple gauge kit (ITPdeisel), "fuel filler mod" (home made), stock 7.3 99.5' 2WD W/ more power than I need. Be green... drink kegged beer! www.micromatic.com you'll thank me

12-12-2011, 09:36 PM	#7
Smoky SDD Member Join Date: Jun 2009 Location: Mississippi State Posts: 341 Thanks: 14 Thanked 28 Times in 27 Posts View Photos By: Smoky	Just a SWAG, clean the battery cables and battery post to ensure good electrical connections? __________________ 2004 F250 Crew Cab King Ranch Lariat FX4 Saddle Leather 6.0 L FUMOTO Valve AIRAID 4" straight No CAT No MUFF Nitto Terra Grapplers All Terrain LT285/75R16 10 PR Everything else pretty much stock NEW Ranchos installed 8/15/2010 Anyone Got Birds? Will Travel to Hunt! We are all just Village Idiots, Enamoured with our own shadow, Oblivious to the setting sun!

12-12-2011, 10:30 AM	#3
Pecoy SDD Junior Member Join Date: Dec 2011 Location: Broken Arrow OK Posts: 7 Thanks: 0 Thanked 0 Times in 0 Posts	That has been the real mystery too. The codes have been different almost every time. The only consistant code was a P3048 or P0348? I think that is what code it was, do not remember for sure. It was the back pressure code.

12-12-2011, 12:12 PM	#5
Pecoy SDD Junior Member Join Date: Dec 2011 Location: Broken Arrow OK Posts: 7 Thanks: 0 Thanked 0 Times in 0 Posts	We have ran all the diagostics, even running the Ford program. The only interesting part of that is when we ran that program, the Ford program read the truck as being a 2000 7.3L with a manual transmission. When we re-ran the program, at the intitial screen, we told it that the info that it was reading was not that truck that it was an '03. At that time it read the truck properly as an '03 with an automatic transmition. I bought this truck used and when we saw that we thought that a new computer had been installed. Still have not ruled that possiblity out either. Yes the EBPV code is what keeps coming up. We thought that could be an issue too so took the pipe apart at the valve and it appears to operating correctly too. I do appreciate the info and I will look more into the EBPV. The part of that and all this is that is strange is that it will only happen on the intitial start up of the day. It does not matter how many start ups or even the temperature of the truck/engine after that intitial start up it will not happen again the rest of the day.

12-13-2011, 06:39 AM	#8
Pecoy SDD Junior Member Join Date: Dec 2011 Location: Broken Arrow OK Posts: 7 Thanks: 0 Thanked 0 Times in 0 Posts	Once it dies I have discovered that I can't immediately crank it back up. Have to wait 30 seconds to a minute and it will immediately crank. The first time this happened to me I did immediately try to crank it and if I remember correctly the tach did move. Now I have noticed once that when the truck first looses power the tach dropped immediately but popped right back up to where the RPM's were at before loosing power. We did get a code one time about loose battery connections so the posts and cables have been cleaned up, checked, and tightened. That code has not reappeared again. This code also was not the first time this happened, more along the third time.

12-13-2011, 07:47 AM	#10
Pecoy SDD Junior Member Join Date: Dec 2011 Location: Broken Arrow OK Posts: 7 Thanks: 0 Thanked 0 Times in 0 Posts	I will see about trying the new sensor also. The truck acted up again this morning and based on a lot of what I have read on here and from a lot of what everyone here has been indicating to me I am starting to lean more towards an issue with the EBPV or piping on it. This morning the check engine light kept flashing on and off, the truck never died, but as I was driving down the road the truck would have a slight "buck" as if it was not getting enough fuel or the engine was starved for air. Any thoughts?

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