Please help, I've been trying to get the following problem solved since last November:

While running the engine will shut off for a brief time. If at idle, it will quit. If not at idle it will "hiccup" but keep running. It does this completely at random. Sometime it happens right after starting, while other time after driving for a while. Sometimes it won't happen for a few days sometimes it happens multiple times a day. Anytime the engine quits, it always will restart without much difficulty. It has never left me stranded (but has left me without power steering/brakes). Sometime it takes and extended time to start (5 sec) while other time it restarts quickly.

Truck details: 1996 7.3L F250 frame. Standard transmission. 200K miles.

Things I've done: New fuel pump. New fuel bowl with regulator, new ICP, new IPR, new CPS and new alternator. None of these things have helped. For a long time, the truck did not "drop" any codes. However, just recently, it registered a 1211 code. This is when I replace the ICP and IPR.

I'm tired of part swapping and this has got me really stumped. If anyone has any suggestion, I'm "all ears".

Thanks for the help.

 

Is your new CPS a Ford or International one? Part store ones are junk. Have you checked the UVCH plugs for burnt pins?

 

oldbird1965 Thanks for the quick reply. I did get the CPS from the dealer. In fact I got two, one gray and one black. I tried both with the same results. Also, I have checked the valve cover connector. It is not melted and seems to be fine. The glow plug resistance is normal.
This is the second PSD I have owned. The first one had a bad CPS. This acts like a
bad CPS but after replacing it twice with factor replacements I've ruled it out.

Could bad injector/o-rings cause all injectors to go "off line"?

 

No but a bad IDM might.

The IDM will shut one bank down if it senses a bad wire leaving you with only one bank to run on.

 

When the "event" happens, the engine just quits and will restart on it's own if not a idle. Otherwise it works just fine. I don't think I'm ever running on only one bank. Could this just be a bad ECM or IDM? I whish I had more codes.

 

Check the pigtails and wiring to the ipr and icp, mainly the ipr. Diesel fuel is hard on wiring and if its like any other obs it has had fuel leaks. Pull the loom off and inspect real close. With the 1211 being the only code in this situation I'm leaning towards wiring right now.

 

Also worthwhile to check the PCM connection on the driver side firewall. Loose, corroded pins, etc. And if you have a chip, confirm that it's connections are sound.

Your description suggests an intermittent electrical connection issue... tough to diagnose and find. Good luck.

 

Check your ground connections. Not just the battery connections, but the ones running from the frame to the body.

Do all of your lights work?

 

427 fordman: When I replaced the ICP, the connector was clean and dry. The pigtail looked ok also. This was not true for the IPR. The connector looked a little "wet". I cleaned it with contact cleaner and loaded it with dielectric grease. I didn't inspect the wiring very closely, but I shake it pretty well to try and induce the problem. I'll go back and pull it out of the plastic wire loom for a better inspection. Thanks for the suggestion.

paddler: While you were writing your suggestion (thanks!) I was removing the PCM to see if it was chipped. It was not, and looked to have never been. The place where the chip would go still had it's protective coating on it. Where the main harness connector goes, I did notice one pin that looked slightly off color. I did my best to clean it, but didn't really try very hard thinking I would cause more damage that good. I sprayed the computer side of the connection with contact cleaner and blew it dry with compressed air and reinstalled it.

CampSpringsJohn: I haven't looked at the ground. I'm not exactly where this is. I'll find out and clean it. All the lights work and I don't have any other anomalies with gauges (except fuel: sender problem I think).

All, thanks again for the suggestions. I'll work through all of them until I find the problem. Someone else suggested that I temporarily disconnect the EBP sensor. Does anyone think this might help? If it can't hurt anything I'll give it a try.

 

Pull the loom off of that whole harness that includes the ipr wiring and the fuel bowl wiring. It's not that much and you need to inspect it all for sure.

 

I pulled the plastic loom off the harness that connects the IPR and fuel bowl.
After inspection, I did find the insulation was slightly dented in places. I also found what appears to be a small nick in both leads going to the IPR. These were so small that under a magnifying glass I'm still not sure the insulation was broke all the way to the conductor.

However, the strangest thing happened. While all the loom was off, I thought I'd start the engine and see if I could induce the problem by aggressively moving the wires. Immediately, the truck started to "miss or try to stall". It seems to clear up when I stopped playing with the wires. I tried this again with the same result. Here is the strange part: when I tried this for a third time, the engine never acted up. I tried for over an hour to replicated the scenario by aggressively playing with all the wiring and connectors but was never able to get it to stall.

Maybe the whole thing is a coincident. I know one thing, it's very, very flustering. I guess I could buy and replace the harness, but I'm not convinced it's the issue.

Any suggestions? I'll check the grounds tonight.

 

For those of you who have been following this thread, I have some new data.

A friend loaned me a scanner and I was able to capture a few sensors as the truck stalled. In an effort to be somewhat logical about displaying the data, I will start with Frame1 truck running normal. Each frame after this is captured in sub second intervals (I'm not sure exactly what this is). Vs=System voltage. Vref is always 5v through this process.

Frame 1: (normal running: idling)
RPM: 653, ICP: 576.02 psi, 0.97v, IPR: 13%, Vs: 13.81v

Frame 2: (initiate stall)
RPM 242, ICP: 301 psi, 0.53v, IPR: 44%[/COLOR], Vs: 13.69v

Frame 5: (everything same as frame2 until frame 5)
RPM: 63, ICP: 159.2 psi, 0.29v, IPR: 15%, Vs: 13.2v

Frame 8:
RPM: 63, ICP: 0 psi, 0.2v, IPR: 15%, Vs: 12.69

Frame 9 (truck dead)
RPM: 0, IPC: 0, 0.21v, IPR: 15%, Vs: 12.62

One interesting note is that the new Ford IPC show 0.2v after the truck stops running. In addition I see this value jumping around 0.2v as the truck in running while the IPR a fairly steady state (13% at idle).

Also interesting is the IPR went up to 44% in frame 2 while the IPC went down to 301 psi. This is a new IPR and I have never seen it above 35% in normal operation.

Any thoughts?

 

Sounds like the PCM is demanding more % from the IPR and the IPR is not responding correctly. 44% is the max the PCM can request on a stock truck. It could be the wiring or plug that goes to the IPR. With the information you provided I would purchase a new pigtail for the IPR, think Riffraff diesel sells them, and replace both IPR harness wires up to the connector on the side of the fuel bowl. Either that or ohm out the two wires from the fuel bowl connector to the IPR connector while wiggling the wires.

 

Jim, thanks for the response. I ordered a new IPR/Fuel bowl harness yesterday. I hope your right and this will fix it. Do you have any concerns that the IPC show 0.2v after the truck is off and bounces around +/-0.2v while it's running? Or is this normal?

 

It's normal. Also Vs is the battery voltage and Vref is always +5 volts and is what powers most of the sensors, except the IPR which is a 12 volt pulsing voltage.