Hello,

I have a 2002 F250 7.3 4WD automatic with 313,000 miles. A week ago it started stalling after it idled for 10 minutes. It acted like it wasn't getting fuel. It would sputter a few times then just quit. I changed the fuel filter and the truck ran fine the rest of the day. Since that day, it has acted the same way every morning at 1st startup. It idles fine for 10-20 minutes (depending on how cold it is outside), then hesitates a little, then stops. After going through 3 new fuel filters (thinking I had bad fuel), I stopped putting in a new filter every morning, and found that if I just waited 4 or 5 minutes, it would start and run fine after that. It then runs fine the rest of the day.

After it stalls, it will not start right away. I need to wait a few minutes.

I've tried draining the fuel filter bowl also. No help. I tried a new Cam Positioning Sensor. No help.

It seems to be related to temperature. It's been getting down to 30 degrees Farenheit the past few mornings. It starts fine and idles fine until the temp gauge just starts to move. Then, the stall happens.

My fill-up just prior to this happening was with B20 Bio Diesel. I suspected that for a while. But, I've ran all that fuel through plus 4 or 5 regular diesel tanks through, so I no longer think it was related to that.

It do see the check engine light when it stalls. I had a shop read my codes and the only code was bad KAM memory. The mechanic said that code shows up all the time on these engines and not to worry about it.

Any ideas?

Thanks, Gary

 

Bad KAM? Do you have a programmer or chip?

Stalling while at OT usually indicates:

ICP
IPR
CMP

echo=on

Injection Control Pressure Tests
Injection Control Pressure Tests (Oil Aeration - Poor idle quality)
All acc. Off
Monitor ICP and RPM with SCAN TOOL Hold engine speed at 3400 RPM for 3 minutes
Spec: ICP: 1800 PSI MAX @ 3,400 RPM

Low Idle Stability (ICP Pressure)
Check at low idle, EOT above 180 F
Monitor ICP and RPM with the SCAN TOOL 400 – 600 PSIG @ 670 RPM’s If engine RPM is unstable, disconnect the ICP sensor, If RPM is still unstable, change IPR and re-test.

Cranking DC% should be 20% - higher indicates malfunctioning IPR. @ 65% IPR is closed

If RPM smoothes out, the ICP sensor is at fault.
Note: ICP will default to 725 PSI when disconnected

Scan Tool - Data List Monitoring:

1. Select the parameters indicated from the Scan Tool parameter list and monitor while cranking engine.

Parameter:
V-PWR 10.5 VDC Minimum.
RPM 100 RPM Minimum
ICP 500 PSI or 3.4 MPAM Minimum
FUEL PW: 1 MS - 6 MS
V-PWR - If indicating a low voltage condition, check battery voltage, charging system or power and ground circuits to the PCM.

2. RPM - Low RPM could be an indication of starting/ charging system problems

3. No RPM indicated with the engine cranking - could be CMP circuit fault, check for DTC’s.

4. ICP - A minimum of 500 PSI (3.4 mPa) is required before the injectors are enabled. No or low oil in the reservoir, system leakage, injector O-Rings, or faulty IPR could cause pressure loss.

Note: If no RPM signal is received, IPR duty cycle will default to 14%

5. FUEL PW - Even though a 1 to 6 mS FUEL PW is shown, it’s possible the IDM did not receive the signal due to a CI or FDCS circuit fault or internal IDM failure.

echo=off

 

Thanks Tom.

I do not have a programmer or chip. At least I don't think so. I bought the truck 5 months ago with 300,000 miles on it. I've put 13,000 miles on since then and it's ran great until now.

I took it to a mechanic and his scan tool did show a KAM memory error. But, he said these show up all the time on the 7.3 and can be ignored. Maybe that's not correct?

I don't have a scan tool myself. Maybe I need one in order to resolve this....

When the engine is cold (30 degrees Fahrenheit), it starts fine and idles at around 1000 rpm. Over the next 10 minutes the idle gradually drops to around 600-700 as the engine warms up. Then, when the temp guage moves about an 1/8th of an inch, we see the stutter and eventual stall.

What does the abbreviation OT stand for?

Also, when my engine cranks, I show NO RPM. Should there definitely be RPM while it's cranking?

Thanks, Gary

 

OT Operating Temperature
You won't show RPM on an 02

You going need to have a scan tool to further testing when the event occurs.

 

Can you recommend a scan tool?

Also, I've seen bluetooth enabled OBDII scanners that use your PC or smartphone. Is there a model like that that will do the job?

 

Any Car Code OBD-II On Board Diagnostics Phase 2 Vehicle Media Communications. Here are a few in alphabetical order.

AutoEnginuity
Bosch
Delphi
Diablo Sport
Edge
Ford DIS
Hickok
NGS
OBDLink SX
OCT
Snap-On

Ps: You get what you pay for when buying diagnostic equipment.

 

The KAM error is a keep alive memory for the pcm. Usually happens after the batteries have been disconnected for about a half hour.

 

Resetting The Keep Alive Memory (KAM)

Description: KAM Failure during Test.

Resetting the KAM returns the powertrain control module (PCM) memory to its default setting. Adaptive learning contents such as idle speed.

Clear the continuous diagnostic trouble codes (DTCs) in the PCM and reset the emission monitors information, is part of a KAM reset.

If an error message is received : "Test Failed - KAM Error", disconnecting the battery ground cable for a minimum of 5 minutes may be used as an alternative procedure.

 

Thanks. I did disconnect both batteries prior to the mechanic finding the KAM error.

It's very strange.... yesterday morning was the 1st morning in the past 10 days that the engine had NO issues on 1st start up. It didn't hiccup and stall at the 15 minute mark like it had been doing.

If I find a solution to this, I'll post it.

 

Did you ever find the problem? My truck is doing the exact same thing.

 

I have not found the issue yet. I have just been living with it the past few months. Once I get past the first stall after it warms up for 10-15 minutes, the truck is fine the rest of the day. Now that the weather is warming up outside (I live in South Dakota), there are times when there is no stall at the start of the day.

I have rented an Auto Enginuity scan tool that should arrive early next week. I'll report what I find when that arrives. I've tried having AutoZone and O'Reilly put their OBDII scanner on to at least tell me what code is being thrown. But, their tools have not been able to read anything.

Look for another post from me in a week.

 

Couple things:

1) I know this sound crazy, but what is your oil level at? If really low, this is common. I was once guilty of troubleshooting a ton of OTHER things, when all I needed to do is add 3 quarts of oil.

2) Is the Tinnerman Nut on your IPR still there, and on tight? If not, could cause this.

3) One of the many things I learned from the Mueckster is that low fuel pressure will manifest itself this way...fine when cold, stalling when engine warms up. Low fuel pressure could be caused by multiple things, here's a short list:
-Fuel bowl has a ton of sediment in the bottom
-Fuel filter is clogged up
-FPR has a sticky plug (or whatever that little metal thing is called, a "regulator" maybe?)
-Dying Fuel Pump
-Clog in fuel line before the fuel pump, which could be at the pickup foot. Disconnect fuel line going into pump, remove fuel cap, blow short blasts of pressurized air down the line toward the fuel tank.

4) Speaking of pickup foot, make sure you have more than 1/4 tank of fuel, in case that foot broke off in the tank. Not likely the issue though, based on your description.

 

Oil level is good. It will fail the day following an oil change.

I received the AE tool yesterday. Idle ICP is 480psi. ICP at cruising speed (60mph) is around 1200-1300psi. I dropped down to around 40mph and then floored it for for 7-10 seconds and ICP maxed out at 2700.

One issue I noted was my Engine Coolant Temperature Input stated 145 degrees F when I 1st started the pickup. It was 32 degrees outside. Intake Air Temp was correct at 32. After 3 minutes, my ECT was 302. It stayed at 302 for 7 minutes then dropped to 13, then gradually increased to 100 during my 20 minute drive. The Engine Oil Temp started out at 66 and gradually rose to 166 - probably correct.

So, I will replace my coolant temp sensor today.

Anything else I should try or look for?

Oh, it didn't stall yesterday after running for 10-15 minutes like it normally does. Figures now that I have the AE tool.

I should also mention that it does throw the following codes:
P1872 Transfer Case 2-wheel drive Solenoid Circuit Failure
P1832 Transfer Case Differential Lock-Up Solenoid Circuit Failure
U1027 SCP (J1850) Invalid or Missing Data for Engine RPM
U1262 SCP (J1850) Communication Bus Fault
B1352 Ignition Key in Circuit Fault
P0500 Vehicle Speed Sensor A
P1211 Injector Control Pressure Higher/Lower than Desired (engine running)

I can clear them. The top 2 come back right away, even without starting the engine. The bottom one always comes back after driving it. The Uxxxx, Bxxxx and P0500 codes showed up only once.

 

No don't change coolant temp sensor. It's reading that way because there's nothing to read.


The problems like these are almost always IPR.


Next time it stalls, immediately hook up AE and monitor injection control pressure as well as duty cycle. Crank for at least 15 seconds. Tell us what it says. I bet ICP is next to nothing and duty cycle will peg out at 64% while cranking. It will also set a code.

 

Yesterday I connected the AE tool and it ran for 10 min then stalled. With the key still on, I cranked it for 15 seconds and it wouldn't start. ICP read 0 during that time. But, all my other sensors (EOT and ECT) read 0 also. So, I turned the key off for 30 seconds. Then, it started up and ICP was around 700 right away, and it ran fine. No more stalls the rest of the day.

I tried it this am and it didn't stall at the 10-15 mark like it normally does.

Yesterday I did disconnect the IPR (I think I pull the correct connector. It's the sensor on the drivers side just below the front valve cover on the inside of the engine, right?). Anyway, the engine started just fine and ran very smooth. ICP stayed at 724 during idle. I drove it and ICP increased like normally does - stayed around 1200-1300 at 60mph, and jumped to 2800 during WOT. My ICP would fall to 450 during idle with it connected. With it unconnected, it stayed at 724.

I've got 316,000 miles on this engine.

I still question the ECT reading. I can see that maybe the water isn't circulating on a cold engine, so the reading initially may not be correct. But, after 10 minutes it will drop from 302 to 13, then gradually increase to around 100. When the engine is fully warm, the EOT is 180. Yet, my ECT is around 100. Either AE doesn't read the ECT correctly or something isn't correct with my ECT sensor.