Greetings. I have a 1999 F250SD 7.3 Diesel (200K+ miles) that likes to quit running every now and then. It always starts fine, but it can die/stumble, after running for about 5-10 minutes -- up until now, it would die for a fraction of a second, (or if it shut off, I could immediately restart it) and then it would continue running perfect for months. It started doing this several years ago. Yesterday it died for about an hour, then started like nothing was wrong. But the difference here is that the horns started blasting about an hour after this last dying episode. This happened after the truck was nicely parked on the street. I shut the horns off via the panic button on my remote. They sounded again after about 5 minutes, and after the third time I pulled the horn relay and fuse. (Take that!) Anyway, I know I have an intermitent problem and now I think I want to disable the factory alarm. Does anybody know how to disable the alarm? Where is the modular located? It may not be the alarm but it's one less thing I have to worry about since I'm stuck in Oceanside CA, 2200 miles from home! I always thought I had a Cam Position Sensor [CMP] issue but I just checked the OBDll and found no DTC's. Help! (Sorry for all the text -- just trying to provide as much info as possible for all the experts out there.
terry

 

When it dies, and it was down for about an hour, would the engine turn, but not take off, or it would not even turn over? And has it been turning over as quickly as it normally does or is it cranking a little slower lately?

 

Franklin2,
Thanks for the reply. My engine would simply stop running. I could crank it like crazy, but it wouldn't show any signs of starting. It's like a gremlin shut off the ignition and fuel systems. To make a long story short, I just replaced the Camshaft Position Sensor (CMP) and I think my issue has been resolved. I think my old sensor was intermittent -- only worked 99.9+% of time. I think the sensor is supposed to provide a signal change after 5 - 10 minutes running time, and I think that's when the problem would occur. This problem has been with me since I bought the truck several years ago (with 197K miles). It would run perfect, and then, out of the blue (after 5-10 minutes running time), it would die. When I first noticed the problem (shortly after I bought it), it would always immediately restart and run prefect for the next few months. Only recently did the problem get worse -- sometimes it would take an hour to start. And when it did, (again) it would start and run like it was a new truck. My only question now is: why didn't my fault reader (Harbor Freight $40 special) pick up any errors. The 'book' shows DTC's for a dead sensor and intermittent circuit. My CPU was clean. PS: The local Oceanside Library had the "All Data" online database and I truly recommend it to our do-it-yourselfer readers. It has all the system schematics, Diagnostic procedures and techinques, Troubleshooting, etc. I hope this information can help at least one of our readers!
Maybe another question is that since my issue was intermittent, why should I expect the problem to be fixed? Positive thinking? Anyway, the engine died 3-4 times just before I switched sensors, and it hasn't died yet (after two days). I'll be on the road back to the Midwest in a few minutes, so that will be my real test. So long California, hello Wayne Illinios. I do have several other issues that I'll post when (if or when) I get back home (3 days).
Peace,
xmot