6.0 stumbles on first start of the day

As the title states the first time I start it after it's sat for a while it will stumble and run really low rpm for a bit. Like for maybe 1to 2 seconds. Then it's fine. I noticed the dummy gauge in the dash will take about the same amount of time to show pressure. I replaced my hpop earlier this year with a used one. Maybe that wasn't a good idea but I did it.

I have no way to monitor the icp ipr or anything. I do have a fuel pressure gauge and it has 55psi so no problem there. When I bought it earlier this year it had really low fuel pressure and I'm wondering if it messed up my injectors?
I have no idea how long it was run that way. They have been replaced but I have no idea when.

It an 04 6.0 with 364xxx miles.
Jus wondering were to start. Any help appreciated!!!

It's ******d also.

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disconnect the icp sensor and see if it makes a difference.

I replaced that earlier but I'll try it!

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If i we're to get a monitoring system what should I get? Dashdaq scanguage2 ? Will an edge cts monitor icp and ipr duty?

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dummy gauge is for low pressure oil.. id start there and make sure you lpo is fine.. what oil are you running?

live life full throttle

Chevron multigrade 15/40

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CyrusLoewen said:

Chevron multigrade 15/40

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switch to a synthetic 5-40 like valvoline extreme blue, chevron delo 5-40.. may even try some archoil or rev-x.. whats your voltage doing on startup? need a volt meter to tell though.. as in, check batteries with the meter while someone starts the truck after a few days of it sitting.. see if its related to that or if its oil related....

live life full throttle

Ok I'll see what I can do!

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I think getting a scan tool on there would be a wise first step. That way you do not waste any money trying to diagnose something you can't see. May be a simple and cheap fix. I learned the "throw money at it" lesson long ago.

We have one called the Infinity. From the same manufacturer of the DashDAQ. The DashDAQ is no longer though. It is now called the nDash. Our Infinity is an nDash with more features and the ability to tune. Check it out HERE.

The low pressure gauge can also indicate a HP oil leak. Just because the gauge isn't reading anything it does not mean the low pressure pump is bad. Every single truck I have fixed with a HP oil leak large enough to create a no start showed no pressure on the dummy gauge while cranking.

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Yah I need to get a scan tool I guess!

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pdumont01 said:

The low pressure gauge can also indicate a HP oil leak. Just because the gauge isn't reading anything it does not mean the low pressure pump is bad. Every single truck I have fixed with a HP oil leak large enough to create a no start showed no pressure on the dummy gauge while cranking.

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It will always start so it's not a big leak if there is one. And hot start it fires almost instantly so I doubt a high pressure leak.

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What year is it? I had an 04 with the old style pump that would start and stall once in the morning and start up every other time until it sat over night and had no other concerns at all. A pump fixed it in that case.

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Yah it's 04 with old style pump.

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lincolnlocker said:

switch to a synthetic 5-40 like valvoline extreme blue, chevron delo 5-40.. may even try some archoil or rev-x.. whats your voltage doing on startup? need a volt meter to tell though.. as in, check batteries with the meter while someone starts the truck after a few days of it sitting.. see if its related to that or if its oil related....

live life full throttle

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I checked the volts and it was 11.8 while the injectors were buzzing and 11.7 while cranking. It seems like it should be over 12 volts the whole time right?

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CyrusLoewen said:

I checked the volts and it was 11.8 while the injectors were buzzing and 11.7 while cranking. It seems like it should be over 12 volts the whole time right?

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being a 6.0. might be ficm voltage you need to check

live life full throttle

Ficm has 48 volts koeo and 48volts while cranking. Don't think that is my problem.

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True about the ficm as possible cause but that normally comes with a code ficm mpwr should be no less than 49v. If you end up getting a scanner to read ICP watch it closely when you first start it, that's where I found my problem. It was like the HP reservoir was leaking down through the pump, first start would use all the oil left in it up it would stall. Start back up and be fine. It was so hard to diag because it showed no other symptoms than the initial start and stall.

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Yah trying to decide wich scanner to buy. I like the one from dptuners but it's $$$ for me!

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