No check engine light. No power

00 f250 7.3 sudden loss of power," limp mode" wont achieve speeds above 20mph. No lights on. Any suggestions?

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7.3 has no "limp mode"


Check output voltage on alternator, check fuel pressure.


Fuel pressure is not monitored by PCM.

Thanks for input.... will post outcomes. Anything else to check for?

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Air filter maybe but fuel probably

Thank you.... i will check it out. I'll let you know.

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Also dont necessarily watch for CEL but watch for water in fuel light if it even just temporarily comes on after you start the truck then it's time to change the fuel filter

wildbill963258 said:

Also dont necessarily watch for CEL but watch for water in fuel light if it even just temporarily comes on after you start the truck then it's time to change the fuel filter

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Knock on wood... i have never seen that light on before. I have had the truck for 15 years.

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Does it feel like a dead pedal?

Need to scan it with a good scanner and pull the codes to help us out. Unless you accidentally put gas in it then it will have a code.

live life full throttle

Nope not a dead pedal.... starts and idles fine, it will have plenty of power for 5-10 minutes of driving.... then fall on its face, clacking and chugging. Getting it scanned now....

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Fuel tank pickup screen is my bet

Magnum PD said:

Fuel tank pickup screen is my bet

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Yep..... that was on my thought train. Thanks for the input.

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Ok.... so, no codes, and once it warms up, blows greyish smoke. And symptoms start.

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Do a buzz test on the injectors.

wildbill963258 said:

Do a buzz test on the injectors.

Click to expand...

Will do, thanks for all the input!

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Derik_C said:

Ok.... so, no codes, and once it warms up, blows greyish smoke. And symptoms start.

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Click to expand...

What are you reading codes with?

live life full throttle

Check the oil level!

Denver said:

Check the oil level!

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Been there done that! Got the t-shirt... same symptoms though....

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Fuel pressure gauge into test port on fuel bowl and go for a drive.

Derik_C said:

Been there done that! Got the t-shirt... same symptoms though....

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Click to expand...

What are you using to check codes with?

live life full throttle

lincolnlocker said:

What are you using to check codes with?

live life full throttle

Click to expand...

Elm327..... i get two codes

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