7.3 powerstroke experts
03-14-2013 | 12:19 AM
#11
Gold Member
Joined: May 2012
Posts: 1,175
Likes: 7
From: Highland Village TX
Not to hi jack northern's thread, but I fought a flashing OD light to wits end last summer... It kept throwing an OSS sensor code. Replace sensor, no change. Under heavy load at low speed (i.e. boat ramp) the truck would buck and stall and shift into OD sometimes locking the converter and stalling.
Long story short, my alternator had a leaky rectifier diode that was back feeding trace AC current to the truck at the right frequency to 'mimic' speed sensor signals. As the revs hit 1100 or so, the signal was that VSS and OSS were way over 100 mph causing it to go into OD and activate the speed limiter fuel cut.
Once the truck was actually moving the sensor output was strong enough to overcome the trace current and the truck drove normal.
Major PITA!
Edit: whenever it would have one of it's full stall episodes it would throw a whole slew of IDM, low voltage, cmp, etc. codes. They were all erroneous, and only happened after a full stall. The ony consistent code was OSS.
Long story short, my alternator had a leaky rectifier diode that was back feeding trace AC current to the truck at the right frequency to 'mimic' speed sensor signals. As the revs hit 1100 or so, the signal was that VSS and OSS were way over 100 mph causing it to go into OD and activate the speed limiter fuel cut.
Once the truck was actually moving the sensor output was strong enough to overcome the trace current and the truck drove normal.
Major PITA!
Edit: whenever it would have one of it's full stall episodes it would throw a whole slew of IDM, low voltage, cmp, etc. codes. They were all erroneous, and only happened after a full stall. The ony consistent code was OSS.
Long story short, my alternator had a leaky rectifier diode that was back feeding trace AC current to the truck at the right frequency to 'mimic' speed sensor signals. As the revs hit 1100 or so, the signal was that VSS and OSS were way over 100 mph causing it to go into OD and activate the speed limiter fuel cut.
Once the truck was actually moving the sensor output was strong enough to overcome the trace current and the truck drove normal.
Major PITA!
The OD light is not flashing in my driveway at idle, when it was flashing it drove normal for the most part, but would waite to shift a bit longer, when I put it in park yesterday it reved up then back to normal. But I noticed it felt differant before I noticed the OD light flashing.
After the whole stalling episode for a year, my Waite to start light stopped working, fixed that, now this! Starting to loose a little faith in this truck. Sad part is, only has a 130k miles.
03-14-2013 | 02:30 AM
#12
Forum Regulator
Joined: May 2001
Posts: 24,205
Likes: 1,594
From: Worldwide
Have you checked the fuses and relays under the hood? There is one I used to pull when I would park at the airport that would let it turn over but not fire. Is your 'Wait to Start' light coming on when you turn the ignition on?
If you have a chip, you may want to unplug it as well.
If you have a chip, you may want to unplug it as well.
03-14-2013 | 06:24 AM
#13
Thread Starter
Gold Member
Joined: Sep 2005
Posts: 2,484
Likes: 5
From: ft. myers, fl.
Have you checked the fuses and relays under the hood? There is one I used to pull when I would park at the airport that would let it turn over but not fire. Is your 'Wait to Start' light coming on when you turn the ignition on?
If you have a chip, you may want to unplug it as well.
If you have a chip, you may want to unplug it as well.
Last edited by northernoffshore; 03-14-2013 at 06:29 AM.
03-14-2013 | 10:06 AM
#14
Registered
Joined: Jun 2004
Posts: 3,397
Likes: 21
From: Somewhere in Ohio
I put my chip back to stock. No warnings on the dash and the glow plugs system is working right. I am going to try and pull fuses and push them back in. I am starting to think i lost the ecm. Which fuse blows when the fuel bowl heater goes? The truck runs once the it's reflashed and the codes erased then if it sits it just turns over and no start.
03-14-2013 | 10:08 AM
#15
Registered
Joined: Jun 2004
Posts: 3,397
Likes: 21
From: Somewhere in Ohio
[QUOTE=Rwbrew3;3885470]
Rick,
My light only flashed while driving and was very intermittent. All your symptoms are very close to mine. Have you pulled the trans codes? Try driving the truck with the alternator unplugged, see if that stops the flashing.
Not to hi jack northern's thread, but I fought a flashing OD light to wits end last summer... It kept throwing an OSS sensor code. Replace sensor, no change. Under heavy load at low speed (i.e. boat ramp) the truck would buck and stall and shift into OD sometimes locking the converter and stalling.
Long story short, my alternator had a leaky rectifier diode that was back feeding trace AC current to the truck at the right frequency to 'mimic' speed sensor signals. As the revs hit 1100 or so, the signal was that VSS and OSS were way over 100 mph causing it to go into OD and activate the speed limiter fuel cut.
Once the truck was actually moving the sensor output was strong enough to overcome the trace current and the truck drove normal.
Major PITA!
The OD light is not flashing in my driveway at idle, when it was flashing it drove normal for the most part, but would waite to shift a bit longer, when I put it in park yesterday it reved up then back to normal. But I noticed it felt differant before I noticed the OD light flashing.
After the whole stalling episode for a year, my Waite to start light stopped working, fixed that, now this! Starting to loose a little faith in this truck. Sad part is, only has a 130k miles.
Long story short, my alternator had a leaky rectifier diode that was back feeding trace AC current to the truck at the right frequency to 'mimic' speed sensor signals. As the revs hit 1100 or so, the signal was that VSS and OSS were way over 100 mph causing it to go into OD and activate the speed limiter fuel cut.
Once the truck was actually moving the sensor output was strong enough to overcome the trace current and the truck drove normal.
Major PITA!
The OD light is not flashing in my driveway at idle, when it was flashing it drove normal for the most part, but would waite to shift a bit longer, when I put it in park yesterday it reved up then back to normal. But I noticed it felt differant before I noticed the OD light flashing.
After the whole stalling episode for a year, my Waite to start light stopped working, fixed that, now this! Starting to loose a little faith in this truck. Sad part is, only has a 130k miles.
My light only flashed while driving and was very intermittent. All your symptoms are very close to mine. Have you pulled the trans codes? Try driving the truck with the alternator unplugged, see if that stops the flashing.
03-14-2013 | 10:35 AM
#16
Registered
Joined: May 2012
Posts: 503
Likes: 26
My 96 f350 7.3 150,000 miles had an intermittent problem.it would quit running and you could restart it in one to ten minutes.It would run for one minute to six weeks. replaced cps nothing replaced icm (injector control module) hasn't quit running in two years. $1000.00 at ford found a new in box ford icm on ebay for $550.00. Good luck with your 7.3 .
03-14-2013 | 12:01 PM
#17
Forum Regulator
Joined: May 2001
Posts: 24,205
Likes: 1,594
From: Worldwide
Did you put the chip on the stock setting, or did you remove it completely? It still has signal running through it if you have one of the ones (like I do, Bully Dog 6 position), which has the Stock|1|2|3|HighIdle|Valet modes. My chip used to act squirrelly, but has seemed to iron itself out.
I'd remove it's plug from the ECM if possible.
I'd remove it's plug from the ECM if possible.
03-14-2013 | 06:51 PM
#19
Gold Member
Joined: May 2012
Posts: 1,175
Likes: 7
From: Highland Village TX
[QUOTE=RT930turbo;3885607]
Had the trans scanned this morning, deffinatley going out.. Not sure what he code was but my mechanic said it's Time to rebuild it! Did say I could dive it as is for a while!
$3300 to fix.....OUCH!!!
$3300 to fix.....OUCH!!!
