I'm stuck. My Excursion (226K miles) has been giving me problems since November. It started suddenly - while going up a hill one day, the engine lost power and ran rough. I shut it down and restarted and everything seemed OK, but did it again as I attempted to continue up the hill. After restarting, I turned around, when down the hill and drove 60 miles home with no issues.

Since then, this problem has been occurring with increasing frequency, at first I thought it was an issue under load, but it got to the point where it would happen when hitting a bump in the road or just going around a corner.

It also happens every time I put the truck in reverse. Anything more than idle would send the engine into convulsions.

I have AE, and everything has pointed to the drivers side cylinder bank. I keep getting P0264, P0266, P0272, P0284, P1296, and occasionally P1316 and P0605 codes. Rarely all at the same time, but always on the drivers side. I've pulled the valve cover several times and the UVCH connection has always looked fine. It has the little Ford clips on the connector, not the 50 cent mod. The truck would usually run OK after these inspections (with the exception of reverse, which has never been OK since this started) for a little while but within a day or two would return to the same pattern.

In the last week, the truck has become undriveable. Coming home last Monday I had this problem occur probably 20 times in 40 miles. Once home, I pulled the valve cover - again - with the same results. Everything looked OK. Only difference was this time it would not idle smoothly afterwards.

Yesterday, I pulled the valve cover and removed the valve cover gasket and UVCH. I inspected the UVCH thoroughly and found nothing amiss. Prior to removal I performed an ohm test and everything tested OK. While in there I replaced the glow plugs (I was getting a glow plug code on this side as well) and injector o-rings. I also replaced the Ford connector clip with a quarter. Buttoned it up and it settled into a nice smooth idle after a few minutes. My optimism disappeared once I put it in reverse. The engine bucked and died. Started it back up, idled OK, pressed the gas and the bucking returned. Let off and the nice idle returned. Did this a few more times, sometimes it wold settle into a nice idle immediately, sometimes not. Basically, the truck is still undriveable.

So I'm contemplating what to do next. This is my work truck and I need to get it running soon.

 

The p0264 is low side short to ground cyl 2. Check the wiring going over drivers side valve cover. These go to the 42 pin connection. They tend to rub causing a short. This pic is a handy reference: Ford Truck Enthusiasts Forums - tdpower's Album: Useful pics - Picture

 

I checked that out thoroughly as well, just forgot to mention it. No issues with it.

 

What were the ohm readings? I've seen a bad injector solenoid ohm out within spec, but be about 0.5 ohms or so off from the other 7 injectors. The bad solenoid can cause the IDM to shut down the entire bank.

 

All four were 0.3 ohms.

 

Here is a link if you need to check from the idm back to injectors: » TB 103: 1994-03 Ford 7.3L IDM Replacement & Diagnostics

When testing the ohm readings at the valve cover check from center pin to each injector.

G - G - I - I - C - I - I - G - G

G = glow plug
I = Injector return
C = Injector common feed

 

That sounds more like glow plugs than injectors. Are you sure you ohmed the injector pins correctly?

 

It might have been the glow plug value - I didn't write any of 'em down. All 4 glow plugs ohmed out the same, and all four injectors ohmed out the same but different than the glow plugs.