Any advice or suggestions would be greatly appreciated….

I bought a1997 F350 7.3 that has 296,000 miles. Bought the truck about 3 hours from my home.The day I bought it i was about half way home and it was running rough so I pulled into a parking lot-as soon as I took my foot of the accelerator to apply the brake the truck died and every light possible on the dash lit up like a Christmas tree!The truck started right back up.Then I made another stop on the way home and the truck did the exact same thing!The truck sat for about a week then I decided I would just take it for a little country cruise and barely made it home…it died on me twice and was running veryrough.The next day my husband and Istarted checking things out alittle closer under the hood.We found several things that needed tightened up and things that we thought could be causing an issue and we removed the TS6 position chip.We took it for another drive and it ran fine.Well the nexttime I went to drive it around the block it died while it was warming up.

I made an appt with the best diesel mechanic in my area…he had my truck for 9 days. Here is what he was texting me while he had the truck….the fuse at the data link has a short and keeps blowing the fuse sohe couldn’t hook up the scanner-found a short in the cigarette lighter circuit-found a bad connection to the fuse box under the hood-replaced the connectors at the valve covers because they were broke-installed a new cam sensor-truck had a PO603 KAM error….he drove the truck and it ran good.When I picked it up he told me to just drive it and see what happens.He said if that didn’t fix it then it was a bad pcm.

About halfway home from the mechanic the truck wasnt wanting to shift out of first gear from taking off at stop signs (never had that issue before). When I got it home we unhooked the batteries and it sat that way for 2 days.Drove it yesterday….it had a hard time starting (never did that before) and it died at a stop sign down the road from my house.Started right back up.Drove itto a friends and it died when it was warming up to leave.On the way to my friends random lights were coming on like the red brake light and it would stay on awhile then go out then the abs light would come on for awhile then go off.

I don’t know what to do with this truck at this point???? I got ahold of my mechanic this morning and he said to bring it back tohim but right now I cant afford another big shop bill.


Thank you for any and all advice you can offer me!
Gwen

 

I highly doubt it is a bad PCM if it is running at all. Remove the valve covers and inspect the under valve cover wires that run from the gasket to the injectors and glow plugs for melted harness/wires, and inspect the valve cover pins for any signs of overheating. If the outer plugs to the valve cover were replaced due to melting, there is a good chance the gasket has burned pins, and needs to be replaced. Do you know if the CPS was replaced with an OEM one or a parts house one? That is one item that should be replaced with a Motorcraft or International one. Mechanics that know these 20 year old trucks are getting scarce, and if yours is saying to replace the PCM because of ruff running, it might be time to ask around for someone else.

 

Thank you for the suggestions.

 

The CPS was replaced with a motorcraft

 

So if he's getting a P0603, then evidently he's resolved the lighter circuit issues and the data link connector works now? And no other codes? He may have to scan it again now that you've driven it and experienced the problem since that fix.

The P0603 itself, don't worry about. KAM is Keep-Alive Memory. It's the memory that's kept by the second power source to the PCM, the one that does NOT go on and off with the key. If the batteries are disconnected, that circuit obviously goes dead and the KAM is lost. That's all that the 603 means. But it also means that any previously stored codes are probably lost as well. That's why it needs to be scanned again AFTER driving it, but without disconnecting the batteries.

 

Pcm fuse blowing, check the cig lighter ashtray slide out, one for my wires worked loose and was shorting mine out.

I was cruising and would have truck die for a split second, happened several times, eventually wouldnt restart. Dead idm. I originally purchased the truck non running that ended up being a bad idm. I ran a ground directly to idm case from battery too.

Had truck die again randomly found short internally at good battery post causing it. No low voltage or low CCA with battery amp tester. Replaced batteries not a single issue since.

 

Why do you keep unhooking in the batteries? Do they go dead if you don't?

 

Madpogue the mechanic did fix the bad lighter circuit and he fixed the data link connector. When he drove it on several occasions for a short distance he scanned it again and no codes at all. The PO603 error was gone.


Shawn we unhooked the batteries hoping it would clear things out and maybe the truck would run good. PLUS...I am worried that since this truck clearly has had shorts in the lighter and data link connector and still has electrical issues I worry about a fire. Figure its better to be safe and unhook the batteries since its just sitting in our shop.

 

Well at some point you're going to have to scan it again, AFTER the issue arises, but BEFORE disconnecting the batteries.

 

If I take the truck to one of the local parts stores and have them put it on their scanner will that be sufficient? Or does it have to be a particular scanner? Just trying to save money and the parts store scanner is free.


Thanks

 

Parts store scanner will NOT communicate with our trucks. Dealerships are known for bending owners over for simply scanning for codes, but a local mechanic, esp. if you've already done business with him and may do more, shouldn't charge you more than a few minutes of his hourly rate.

You could also consider setting yourself up. Several high-buck options. The two low-buck options becoming popular are a bluetooth ELM327 dongle combined with an app called CarGauge Pro, or a USB dongle combined with an app called ForScan. I haven't used either, but there are several threads here and on the other PSD sites with loads of info.

 

If you plan on owning an OBS PSD you might as well just buy Auto Enginuity with the ford enhanced program. Or if you are planning on using a chip i use the Edge CTS2 programmer which will scan and display IPR% ICP etc.

https://www.amazon.com/Edge-Products.../dp/B00XM16N4G

AutoEnginuity Total Ford Scan Tool Package Enhanced Bundle SP03

 

I made another appointment with my mechanic. My dad and brother just went to my house to get the truck and drop it off at the shop again. My Dad said it took 3 tries to start it, he then pumped the accelerator one time then tried again and it started (just like the other day) and my Dad said the truck is noticeably missing. I guess I will wait and see what the mechanic finds this time.


I was planning to leave the truck stock. Already took out the TS6 chip because I thought maybe that was causing an issue.

 

Pumping the accelerator had no effect. It would be equivalent to playing with the volume control on a radio while it's turned off.

+1 on having the chip out. Keep it out at least until you have it running right, to avoid complicating the issues.

 

I have another question....is it normal for a 1997 stock 7.3 to be "doggy"....as in the other day I wanted to see if it would cut out when I was in my gravel driveway so I was at a complete stop and pushed the pedal pretty much to the floor and it wouldn't even spin the tires on rocks. Is that normal? I used to have a 1999 flatbed f350 with a manual tranny and it sure had ALOT more pep than this truck does. Should have kept that truck! Had it 9 years and only had to put a new water pump, starter and tires on it during that time. Lesson learned