A friend of mine has a 97 F-250 4X4 7.3 diesel Crew Cab that I sold them 3 years ago. A couple days ago they took off in it and it went about a 1/4 mile and died. They thought it might be the PATS system because the truck had been broken into a couple months ago and some wires messed with. The truck will turn over and the Tach moves, but has no oil pressure showing and no fuel going into the filter canister. I'm at a loss on what to do. I really hate taking it to the Ford dealer. I need to eliminate some things one at a time. How do I know the PATS isn't the issue? It was very low on oil, but I have filled it back up to the full mark. Please give me some idea what to look at first and maybe some kind of checklist to go thru.. Thanks!!!

 

Sounds like it needs a fuel pump at least if it has no fuel going to the filter. You can try and check the fuel pressure on the shrader valve on the side of the fuel bowl with a cheapo tire gauge.

 

As far as I know, OBS trucks didn't have PATS.

The fuel pump on the OBS 7.3 is manual from the factory. Unless it has been upgraded to electric, it should be pumping fuel if the engine is spinning.

Make sure fuel tank is above 1/4 tank. The showerhead pickup tube in the tanks rot off and then you can't pick up fuel if it is below that amount.

I don't have a link to the no start flow chart, but I will look for it.

Kevin

 

Found the flow chart.

Kevin

 

Thanks Kevin, the truck has a PATS, "Passive Anti Theft System" on it under the dash and it has cause me issues before. I thought the 97 was like all my other trucks, 99, 2001 & 02 and had an eiectronic fuel pump. I will check tomorrow for fuel flow while cranking the truck over. Both fuel tanks are full, so the pick up bell isn't an issue.

 

OK, we finally got it running by resetting the PATS system several times and had to do it a few more times in the last 2 weeks. I need to find a way to remove the PATS system completely. Does anyone have a good wiring schematic that I can look at to see what wires need to be paired up to bypass the system?

 

Mine is partially disabled and doesn't cause a no start but will lock the truck sometimes. My key is in the ignition of course.

 

How did you disable yours? Do you have the wiring diagram? Thanks

 

I just blindly cut some wires. I'm sure glad I hide a key under the truck, locked me out again two days ago! I would like a wiring diagram also.

 

This is factory? Somebody must have a 1997 EVTM.

 

I believe mine is aftermarket.

 

It didn't have PATS when it left the factory. No OBS truck did.

 

^^^^^ Not sure what constitutes PATS, but the 1995 trucks could be had with anti-theft, according to both my 1995 owner's manuals. I just don't know if that particular anti-theft is "passive".

 

PATS has a transponder in the key. The transponder sends a code when inserted and must match the code stored in the PCM, which we don't have. If it's killing the fuel and have mechanical fuel pump then look for a cutoff solenoid in the fuel line somewhere.

 

^^^^^ Yeah that's Flash Gordon compared to anything on an OBS.