I have a 1995 E-350 7.3 turbo diesel truck that has been giving me grief for weeks! I was driving it and it shut off and restarted on it's own. I parked the vehicle and when I went to leave, it wouldn't start. We originally thought it was the fuel pump so we replaced the mechanical fuel pump. Still no start. We replaced the fuel filter (prior to this issue) as well. Glow plug relay was checked and is fine. The fuel pressure at the schrader valve was 45 psi. The oil pressure at the head was 3500 psi. We replaced the cam sensor, checked all the fuses and relays. We swapped out the IDM box, even though there was nothing visibly wrong...no water damage viewed. Still no start.
The "wait to start" light does illuminate and no DTC codes are read, however, when the "wait to start light" goes out, I get a "communication with your vehicle has been lost" message?? Might be signifigant of something or not? We have had two mechanics working on this and one brought a machine from his shop to "pop the injectors" and they all popped. We've been working on this for weeks...any help is certainly appreciated! thanks,
Tom

 

Not sure where they are on a E series , but may want to test the small relays in the fuse box . On a truck there are 4. you can use the one for the horn to test the rest ..

 

I have read that some cps are bad right out of the parts store and it is best to get them from ford or ih. Where did you get yours at

 

Welcome to FTE. Losing communication with the PCM when the WTS light goes out is odd. Can you monitor live data with your scanner? Does it re-establish communication or can you see RPM's while cranking with the scanner?

What happens if you ignore the WTS light and start it up like it was a gasser? Does the scanner lose communication while cranking, or just when the light goes out? Is there a chip in van?

 

Thanks for answering. I had checked all the fuses and relays and they were all fine. The CPS was purchased from Ford and we changed out with more than one so I'm thinking that's ok too. We also changed the IPS as well.

Our code reader checks 1996 and newer models but the manuel states that it can read 1994-1995 OBD II certified vehicles. Our sticker inside the truck is missing so we can't verify it but it has 16 pins and does link up.

When we hook the monitor into the truck, it reads no DTC codes are present. When we hit the "live data" button, it starts to link until the WTS light goes off, then all we get is a "lost connection with the vehicle" error message. We also get this error message if crank on the truck and WTS light is ON.

The chip you are referring to...is that at the front of the motor in the wiring harness? If so, we replaced that. If that's not what you're referring to, please advise.

We called the Ford dealer and asked if they could test our IDM. They said the problem is usually a wiring problem. We have examined the wires and there is no visible signs of corrosion or wear or tear. I guess it's possible that there is something underneath the insulation, but I find that unlikely given the look of the exposed wires.

This is getting very frustrating as they truck has been down now for over 6 weeks. We are willing to try any suggestions.
Thanks!
Tom

 

The chip usually sits on the back of the PCM. Sometimes it might has a loose connection and cause problems. I'm guessing that you removed a 10K resistor mod, a poor man's mod to increase performance. If that's the case then its good you removed it for testing purpose to get it running. I'm not sure where the PCM is on the Van but if you find it see if there is a 'chip' that piggy backs the back of the PCM and remove it for testing purpose. Good Luck!