Need feedback on issue (2024)

Brian1959 said:

62Blazer, I just scanned and showing a P0440 evap code

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I wouldn't expect that code to cause any drivability issues. Did you have a check engine light? If no light that was probably just an old stored code.
Does your scanner have any live data capabilities?

Brian1959 said:

62Blazer, I just scanned and showing a P0440 evap code

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If your evaporative system purge solenoid is stuck “open” - it can allow fuel vapors to enter the intake system at idle, causing the engine to stall (such as when coming to a stop and lifting the accelerator pedal).

It can also cause a rough idle.

It can also cause the engine surging while driving at speed - but at light throttle (such as driving 50 mph with light throttle on level road and trying to maintain your speed).

Brian1959 said:

62Blazer, whe the truck is fired up it runs like a brand new truck, it isn't until you get cruising whether it's through town here or on the backroads, when cruising the rpms surge as i noted and now since this morning stalls out and dies upon slowing to a stop. and it literally feels as if someone shut the fuel off. So my plan at the moment is fuel pump replacement, throttle body replacement and if needed i'll replace the purge valve too. I did do a throttle relearn haven't tested it yet, but we'll see. In the meantime 62Blazer i appreciate your input still kinda like the simplicity of my 78 ford lol!!

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That sounds like you're starting up the parts cannon before completing much diagnostic work that identifies anything specific.

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RamDiver said:

That sounds like you're starting up the parts cannon before completing much diagnostic work that identifies anything specific.

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Just a bit of a cannon lol!, after 45 yrs of turning wrenches on my stuff and military......patience has worn thin for diagnostics these days. Leave the diagnostics for young bucks! Now if i can find where i left my beer alls good! Lmao! have a good one

A code P0440 could mean one or more of the following has happened:
The gas cap is not installed or working properly , <--- very unlikely, Only use Mopar Cap, IF you truly need to replace it
The purge solenoid has failed
The canister is plugged and not working properly

Possible Solutions
With a P0440 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:
Remove and reinstall the gas cap, clear the code, and drive for a day and see if the codes come back.
Inspect the EVAP system for cuts/holes in tubes/hoses
Inspect for damaged or disconnected hoses around the Evap purge solenoid
Check and/or replace the sensor Check and/or replace the purge valve
Have a professional use a smoke machine to detect leaks

Read more at: https://www.obd-codes.com/p0440
Copyright OBD-Codes.com

Brian1959 said:

Just a bit of a cannon lol!, after 45 yrs of turning wrenches on my stuff and military......patience has worn thin for diagnostics these days. Leave the diagnostics for young bucks! Now if i can find where i left my beer alls good! Lmao! have a good one

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From what I usually see, it's mostly the young'ins that don't have the patience for analysis.

I worked in Telecommunications for about 35 years before retiring almost 10 years ago.

My brain won't allow me to not perform diagnostics, maybe, I need to change my medication.

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GTyankee said:

Inspect the EVAP system for cuts/holes in tubes/hoses

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I've had a couple of vehicles where this one has had me chasing it for a bit....that and my kids vehicles forget to tighten the gas cap after filling....

to Ram Forum @Brian1959.

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JW2 Innovations said:

my kids vehicles forget to tighten the gas cap after filling....

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Or the wife

Brian1959 said:

62Blazer, whe the truck is fired up it runs like a brand new truck, it isn't until you get cruising whether it's through town here or on the backroads, when cruising the rpms surge as i noted and now since this morning stalls out and dies upon slowing to a stop. and it literally feels as if someone shut the fuel off. So my plan at the moment is fuel pump replacement, throttle body replacement and if needed i'll replace the purge valve too. I did do a throttle relearn haven't tested it yet, but we'll see. In the meantime 62Blazer i appreciate your input still kinda like the simplicity of my 78 ford lol!!

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Many years have passed since the simplicity of a mechanical fuel pump on your 78 fotd. A bit of work to replace an electric fuel pump that is working when you drive it and would have more stable pressure when you come to a stop and idle.

I am not positive, but on that year Dodge Ram ..

The purge valve might almost under the battery
If i recall correctly, it has an arrow imprinted on the housing, arrow points up.
BUT your year truck, the Purge valve may be as shown in the video below

Remove the purge valve, that is fairly simple.

Now try to blow through the purge valve hose fitting.
Without the electrical being plug in, you should NOT be able to blow through the Purge Valve, IF you can blow through it, there is a very good chance that the Purge Valve is bad

There are YouTube videos on purge valves

and another tidbit

There's also a fuel pressure regulator down below the brake booster (behind engine).There's some good videos on it. Just type it in to Youtube search.

But you might be right on the fuel pump. They tend to start not pumping well when they get 'hot' ...which is around 15-20 minutes ..depending on the temp of the day/fuel. Harbor Freight used to sell a fuel pressure test kit ..I think they still do. I think Autozone and maybe OReilly Auto rents them for free. That would be the thing to zero in if it's really fuel pressure or not. You might try to swap the relay too in the engine compartment.

Replacing the fuel pump is NOT a particularly fun job with driveway tools ...esp with some gas in the tank. Or on a hot humid mosquito-y day...if you do a driveway job. The test however is not difficult to do. I would want a fairly high degree of certainty on the pump before I jumped into it. Speaking for myself there.

If you do it, I would replace it with a name brand pump ...myself. Best of luck. Let us know what you discover.