Can anyone help decipher freeze frame data please?

[n.shift]

I have a 2001 expedition with codes p0171 p0174. Sometimes but not always, It also has long cranking times before it starts. once its running its runs great. its 5.4 L 117k miles. Any thoughts on this? thank you
I forgot to mention it only does this when cold. when I say cold, I mean 30 degrees outside. Im thinking leaking intake gasket. Freeze frame data is

 

[docraymund]

You have a lean condition most likely a weak fuel pump or dirty fuel filter.

 

[J_82]

Could be a intake leak or a weak fuel pump or clogged up fuel filter? How does it drive on WOT going down the road?

 

[n.shift]

You have a lean condition most likely a weak fuel pump or dirty fuel filter.

Are you saying weak fuel pump do to the freeze frame data? I’ll check my fuel pressures soon. Filter is new

 

[silverexp]

You say filter is new. Did you change it because you were experiencing hard starts with a check engine light on? Or was it part of your maintenance routine? Why are you thinking leaking intake gasket?

 

[J_82]

The code indicates the system is running lean. Lean means you have less fuel to air ratio. The system is always trying to maintain a specific air/fuel ratio. The system is constantly making minor adjustments to achieve the desired air/fuel ratio. When it makes major adjustments and it’s still not at the desired air/fuel ratio it detects something is wrong and throws out a code.

P0171 can mean you have excess air coming in or less fuel. These(fuel filter, fuel pump, leaking intake) are some but not all conditions that can cause that symptom you are experiencing.

 

[n.shift]

You say filter is new. Did you change it because you were experiencing hard starts with a check engine light on? Or was it part of your maintenance routine? Why are you thinking leaking intake gasket?

Fuel filter was changed as part of routine maintenance about a year ago. I’m thinking vacuum leak because if you look at rpm, the code triggered at 868 rpm. My obd2 test doesn’t have live data. I can find any vaccum leaks. I’m going to smoke test it soon. But I’m thinking I take gasket because once weather is warm or suv engine gets warm, things run better. I believe the rubber gasket is shrinking in the cold and swelling in the warm/hot. This is just a gut feeling. I could be wrong. These freeze frame data are suppose to point you in one direction or the other. But I’m uncertain which way to go with these numbers

 

[n.shift]

The code indicates the system is running lean. Lean means you have less fuel to air ratio. The system is always trying to maintain a specific air/fuel ratio. The system is constantly making minor adjustments to achieve the desired air/fuel ratio. When it makes major adjustments and it’s still not at the desired air/fuel ratio it detects something is wrong and throws out a code.

P0171 can mean you have excess air coming in or less fuel. These(fuel filter, fuel pump, leaking intake) are some but not all conditions that can cause that symptom you are experiencing.

The freeze frame data should point you in a direction of vaccum leak or fuel/sensor related. But I’m uncertain which

 

[J_82]

The freeze frame data should point you in a direction of vaccum leak or fuel/sensor related. But I’m uncertain which

Right you have to troubleshoot some more. If the leak is big enough you can spray carb cleaner around the intake leak and vacuum will suck it up and you might here a difference in RPM. This is a cheap way to troubleshoot a intake leak but doesn’t always work.

 

[n.shift]

Right you have to troubleshoot some more. If the leak is big enough you can spray carb cleaner around the intake leak and vacuum will suck it up and you might here a difference in RPM. This is a cheap way to troubleshoot a intake leak but doesn’t always work.

Think a smoke test would find a small leak?

 

[silverexp]

Fuel filter was changed as part of routine maintenance about a year ago.
I’m thinking vacuum leak because if you look at rpm, the code triggered at 868 rpm. My obd2 test doesn’t have live data. I can find any vaccum leaks. I’m going to smoke test it soon. But I’m thinking I take gasket because once weather is warm or suv engine gets warm, things run better.

Ice could be an issue there, especially if you're using ethanol gas. Also, engine and ambient temps come into play with fuel mixture. The pcm uses those parameters to determine proper fuel trim.

I believe the rubber gasket is shrinking in the cold and swelling in the warm/hot. This is just a gut feeling.

That's a possibility...

I could be wrong. These freeze frame data are suppose to point you in one direction or the other. But I’m uncertain which way to go with these numbers

All you need to know from these numbers is that you have a lean condition. That's about all they'll tell you. If you understand what causes lean conditions, run with that. With my wife's expy, to trace that lean condition after putting the vehicle back together, I checked fuel pressure with a cold engine, not running, and it was about 4 psi above minimum. So I then checked egr valve function, egr solenoid, evap solenoid, vacuum line condition, even checked vacuum with a gauge. Everything was within spec. So I bought a fuel filter and changed it, even though pressure was good, and found a lot of trash in it. Then it dawned on me that a tank or two before I started having problems I ran seafoam through it, which ended up plugging that filter. Don't rule it out...

The freeze frame data should point you in a direction of vaccum leak or fuel/sensor related. But I’m uncertain which

Freeze frame only tells you the conditions under which the light was set. The CEL doesn't always set right away. Sometimes the pcm will detect a problem, and then monitor that system for so many cycles before setting a code. That's the difference between a hard fault and a pending fault. The only useful information from that freeze frame is that your long term fuel trim on one bank was out of parameters for too long. That it set the light at idle with engine warmed up is irrelevant, especially since your hard start happens with the engine cold.

 

[J_82]

Think a smoke test would find a small leak?

Yes it can.

 

[n.shift]

All you need to know from these numbers is that you have a lean condition. That's about all they'll tell you. If you understand what causes lean conditions, run with that. With my wife's expy, to trace that lean condition after putting the vehicle back together, I checked fuel pressure with a cold engine, not running, and it was about 4 psi above minimum. So I then checked egr valve function, egr solenoid, evap solenoid, vacuum line condition, even checked vacuum with a gauge. Everything was within spec. So I bought a fuel filter and changed it, even though pressure was good, and found a lot of trash in it. Then it dawned on me that a tank or two before I started having problems I ran seafoam through it, which ended up plugging that filter. Don't rule it out...



Freeze frame only tells you the conditions under which the light was set. The CEL doesn't always set right away. Sometimes the pcm will detect a problem, and then monitor that system for so many cycles before setting a code. That's the difference between a hard fault and a pending fault. The only useful information from that freeze frame is that your long term fuel trim on one bank was out of parameters for too long. That it set the light at idle with engine warmed up is irrelevant, especially since your hard start happens with the engine cold.

But at higher rpm’s wouldn’t a vac leak be irrelevant? That’s why it’s inoortant to see at what rpm’s the light was set. I really need a obd2 scanner with live data . So what should fuel pressure be with key off, key on and running? I believe mine is the returnless fuel system

 

[J_82]

But at higher rpm’s wouldn’t a vac leak be irrelevant? That’s why it’s inoortant to see at what rpm’s the light was set. I really need a obd2 scanner with live data . So what should fuel pressure be with key off, key on and running? I believe mine is the returnless fuel system

If you think it’s fuel pressure related then check fuel pressure at WOT. If it drops too much then there is the cause of your issue.

 

[silverexp]

But at higher rpm’s wouldn’t a vac leak be irrelevant? That’s why it’s inoortant to see at what rpm’s the light was set. I really need a obd2 scanner with live data . So what should fuel pressure be with key off, key on and running? I believe mine is the returnless fuel system

A vac leak would be more noticeable at idle, but like I said, that may be coincidence that the pcm set the code at idle. The pcm likely picked up a problem before that and monitored for so many cycles, and that happened to be what the rpm was on that cycle when it set the code. Notice your engine temp was 194°. To me that's more relevant than rpm. Either way, you have a lean condition to track down.

As far as scanners go, I use torque pro and forscan apps with a wireless obd2 device. Total cost was $25-$30, and I use those way more than my $200 Innova scanner. And they provide you with the option to track realtime data.

Engine running fuel psi should be between 28-45. Key on engine off should be 35-45. Mine was at 32 running and 39 off with a bad filter.

 

[silverexp]

If you need any technical information, I have all of the workshop manuals for the 2001 expedition. All you have to do is ask.

 

[n.shift]

If you need any technical information, I have all of the workshop manuals for the 2001 expedition. All you have to do is ask.

I’m asking but i really don’t no what I’m asking for. Lol. You have anything to put me in right track to solve this leak condition on bank 1 and 2 with fuel pressure specs?

 

[n.shift]

A vac leak would be more noticeable at idle, but like I said, that may be coincidence that the pcm set the code at idle. The pcm likely picked up a problem before that and monitored for so many cycles, and that happened to be what the rpm was on that cycle when it set the code. Notice your engine temp was 194°. To me that's more relevant than rpm. Either way, you have a lean condition to track down.

As far as scanners go, I use torque pro and forscan apps with a wireless obd2 device. Total cost was $25-$30, and I use those way more than my $200 Innova scanner. And they provide you with the option to track realtime data.

Engine running fuel psi should be between 28-45. Key on engine off should be 35-45. Mine was at 32 running and 39 off with a bad filter.

Should there be pressure with key off? Or should it be zero?

 

[silverexp]

Should there be pressure with key off? Or should it be zero?

There should be pressure at all times. It is supposed to hold whatever pressure was there when the engine was turned off. Mine, IIRC, held at 38.

 

[silverexp]

How is your PCV valve? Reason I ask is that a sticky pcv valve can create a vacuum leak, and that's about a $3 part.