Hi everyone,

I have a 2001 Ex 7.3L that started very hard yesterday and ran rough, as though it had a serious misfire or bad fuel. Idled rough and since I had the doors open part of the day, I thought maybe the battery was low or it had a bad alternator. Anyway, today I went to start it and it ran rough but started. Tried to move it out of the driveway and it ran REALLY rough/poorly and had little power.

Truck was running fine before this issue. No leaks, good power, etc.

Pulled back in to the driveway and now it won't start. Checked the DTC's and found a P0340 code set. Replaced the CPS with a Ford part, same no start condition.

Checked the fuel bowl for water or contaminants, found none. Checked the oil for signs of water, found none.

Read the forums and saw the posts about checking the ICP sensor by unplugging it and seeing if the truck would start, but it doesn't. Replaced the ICP anyway (340k miles, figured it was time and it was leaking oil in to the valley anyway).

Checked the harnesses and they look OK. Don't see any chafing or abnormal wear. I know this truck pretty well after 340k miles. Ran great Saturday, now nothing.

SES light is not on and there are no indications anything is wrong other than the no start and the previous code(s). Turns over fast and tries to catch (like one or two cylinders fire) but basically just cranks. No codes set since I cleared them after replacing the ICP, not even P1000. Wait to Start light operates normally.

Batteries are good, alternator is good. What's next (besides the dealer)?

Scott
Wellington, FL

 

I would be checking the undervalve cover harness. The clip on the inside tends to come loose over time. You can OHM that out from teh outside if you have an ohm meter.

The otehr thought that comes to mind is the huge wire bundle over the drivers valve cover, it has been known to rub on the valve cover and short out things. can kind of feel under it to see if its worn through the red tape, at least its red on mine.

 

Have you done the 50 cent mod? Sounds like you need to check under the valve covers. I don't have a link for you, but I know others will. Or you can do a search.

edit: the lion hunter got me!

 

What are you using to read and clear the codes? Can you monitor any live data with it?

When you turn the key to ON, can you hear the fuel pump come on (this isn't a fuel related question)? Is there any smoke out the tail pipe while cranking? If you crank the engine for 20 seconds, does it trip any codes?

 

Thanks for the replies.

The wiring looks fine. The harnesses are plugged in securely.

I do not hear anything running when I turn on the key, like the fuel pump. In response to that question, I checked the fuel pump reset switch (OK) and the fuel pump solenoid maxi-fuse, OK. No smoke while cranking. Oil level is fine.

Reading through the forums I see a lot of IPR issues coincidental with no-start. Can I check the IPR without a Ford scanner? I don't want to spend another $180 on another part that turned out to be OK.

What now? Can't locate my shop manual, that's how trouble-free this 7.3L has been :-)

Scott

 

Have someone turn the key to WTS while you are under the truck and make sure the fuel pump is running. Even then, with that kind of mileage it probably does not have a lot of umph if it is the OE unit.

 

UPDATE:

I can hear the fuel pump running (like a hum but very faint in the fuel tank?). I checked the Fuel Pump fuse and swapped out the relay, same result. I drained the fuel bowl, turned the key on and the fuel bowl filled up.

What now? Sure appreciate the help. Money's tight and if I can avoid the dealer I will be able to eat this week :-)

Scott

 

Your fuel pump should be on the frame rail under the driver seat. It looks a lot like a fuel filter for a gas engine. If the fuel pump is not getting power, there's a circuit in the PCM not firing things up properly. This might be just a chaffed wire somewhere. We're just trying to determine which circuits are getting power to know which direction to go.

 

The fuel pump is running and the fuel bowl fills after being drained.

Today I pulled the IPR and thoroughly cleaned it, checked it for continuity (10.7 Ohms, same as the new one I bought), made sure the plunger moves freely, bead blasted the outboard end and re-installed it. Don't think the IPR is the problem.

I checked every fuse, relay and diode relating to the engine controls both under the dash and under the hood.

Same thing, just cranks and seems like it's trying to catch but it doesn't. I can smell fuel from the tail pipe but there is no white smoke as was mentioned above.

Now it has thrown a new code: "P1670 EF Feedback Signal Not Detected" and the familiar P1000.

I'm at a loss. Any ideas or do I need to get it over to the dealer for a scan?

Thanks for all the help. After four days of frustration I'm pretty well stumped.

Scott

 

Did you check the fuses with a test light or a meter? You really need to do this just to be on the safe side. After that, I'd look into the 1670 code issue, which has to do with communication between the IDM and PCM. You can use your handy multi-meter to check for continuity. Be sure to wiggle the wiring harness while testing to watch for any intermittent shorts.

IDM Pin out

PCM Pin out

IDM harness testing

 

Update: Got frustrated and had the truck towed to my local garage who determined that I need a new fuel pickup in the tank and a new fuel pump, for $1200+.

Decided I could do both myself, bought a new fuel pump, cleaned out the fuel bowl and replaced the fuel filter. Installed the new pump and blew air back in to the fuel line between the pump and the tank to dislodge any crap on the screen.

The truck now starts and runs GREAT for about 20 seconds then sputters and acts like it's running out of fuel, or there is air in the line, etc.

The output of the pump is about that of a beer tap, that is it will fill a 1 gallon jug in say, about a minute if I let it run. Is that sufficient?

Figuring even if the tank screen/strainer isn't clogged, it will be eventually, I order the Sinister Diesel pre-tank filter/modified tank pickup kit.

What's next (besides the obvious drop-the-tank and install the tank /filter kit)? Seems like the pump sure is pushing enough fuel...? But is it supposed to be at a higher rate/pressure?

Appreciate the help. Getting closer. At least the electrical issues are off the table.

Scott

 

if your concerned that the fuel pickup is clogged how about running a fuel line from the pump to a fuel can to see if she runs longer than 20 seconds?

 

Exactly what I plan for Monday. Unfortunately I have to leave for business until Monday, so the truck is going to sit for a few days. The tank kit is due in next Tuesday and I'll probably install next Weds. What a PITA, but after 360k I guess I can't complain.

I'll update when I see if the truck will run off a fuel can.

Scott

 

Make sure you don't have a kink in your fuel line coming from the pump. I performed the fuel tank mod and when I reinstalled the tank my fuel line became kinked and my truck would barely run.

 

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