After searching the forum I have found similar symptoms, but not the same. Here's what began about four weeks ago and is getting worse...

1. Slow start-up. The longer it sits, the longer it takes to start. Sitting for 1hr - 3 or 4 cranks, 4hrs - @8 cranks, over the weekend - lose count (5 seconds to start).

2. Loss of power (falls flat) @2800rpm full throttle. I know there is a rev limit, but I use to get 32-3400rpm before a shift. Now from a dead stop (toll booth, etc.), I start at half throttle and gradually go to wide open while merging in traffic. Acceleration is great then I almost get thrown out of my seat as soon as I hit 2800rpm. There is a 2-3 second flat (no power) period then all of a sudden it continues to @32-3400rpm and shifts. A real pain if your jockeying for good position in traffic. BTW... occurs with/without towing.

The dealer says no codes and they performed the "text book" diagnostic. They want me to leave it sit in their lot for two days so they can repeat the hard start. I changed the filter (followed instructions from here... Thanks!) but after closing bleeder screw, fuel ran out of the water drain valve as the primer pump got harder to push. Checked the valve, it is tight and no leaks while driving or sitting in garage. One more thing... I don't hear any pump noise from the tank when I turn the key, but I can't remember if I ever did before these probs started.

Lift pump prob? Air getting past water drain valve allowing fuel to run back to tank when not running and IP sucking air through valve at high rpm? I'm hoping the dealership doesn't blame it on bad fuel and charge me for a pump.

I want my power back. Help me trouble shoot.... Please!

Thx,
Jason

OK, number one-- the truck does not have a fuel pump- the CP3 draws fuel from the tank! Unless someone installed an aftermarket unit. Sounds like it is loosing prime-- may be filter housing-- try pumping the primer button before you start it. How many miles on the fuel filter-? Air filter?

Also a little off topic-- be sure you are saving $$$ for the trans-- you are going to need one before long, and they are expensive!:eek:

After searching the forum I have found similar symptoms, but not the same. Here's what began about four weeks ago and is getting worse...

1. Slow start-up. The longer it sits, the longer it takes to start. Sitting for 1hr - 3 or 4 cranks, 4hrs - @8 cranks, over the weekend - lose count (5 seconds to start).

2. Loss of power (falls flat) @2800rpm full throttle. I know there is a rev limit, but I use to get 32-3400rpm before a shift. Now from a dead stop (toll booth, etc.), I start at half throttle and gradually go to wide open while merging in traffic. Acceleration is great then I almost get thrown out of my seat as soon as I hit 2800rpm. There is a 2-3 second flat (no power) period then all of a sudden it continues to @32-3400rpm and shifts. A real pain if your jockeying for good position in traffic. BTW... occurs with/without towing.

The dealer says no codes and they performed the "text book" diagnostic. They want me to leave it sit in their lot for two days so they can repeat the hard start. I changed the filter (followed instructions from here... Thanks!) but after closing bleeder screw, fuel ran out of the water drain valve as the primer pump got harder to push. Checked the valve, it is tight and no leaks while driving or sitting in garage. One more thing... I don't hear any pump noise from the tank when I turn the key, but I can't remember if I ever did before these probs started.

Lift pump prob? Air getting past water drain valve allowing fuel to run back to tank when not running and IP sucking air through valve at high rpm? I'm hoping the dealership doesn't blame it on bad fuel and charge me for a pump.

I want my power back. Help me trouble shoot.... Please!

Thx,
Jason

Check to see if you cracked the water in fuel sensor. They are plastic and crack easily when over tightening. I wouldn't think fuel would run out the bottom unless you did crack it.

Also, did you put the gaskets on? Sometimes folks forget to put them on or forget to take the old ones out. That would cause the loss in prime.

OK, number one-- the truck does not have a fuel pump- the CP3 draws fuel from the tank! Unless someone installed an aftermarket unit. Sounds like it is loosing prime-- may be filter housing-- try pumping the primer button before you start it. How many miles on the fuel filter-? Air filter?

Also a little off topic-- be sure you are saving $$$ for the trans-- you are going to need one before long, and they are expensive!:eek:

OK... sorry. Went from a gas suburban to a diesel truck and still learning. Haha, guess a pump in the tank is not the prob. Just changed fuel filter after prob started. The water bleeder was leaking before the change. Previous filter had 4,000mi. The fuel comes out the hole in the bottom of the screw and the new gaskets are both in place. There was some solid debris in the water sensor that I cleaned out. The leak is fuel getting past the little rubber plug up inside the water bleeder valve. Even when it is really tight. Maybe the debris damaged it. I didn't see any cracks in water sensor and my air filter is clean (I inspected) and only 4,000mi since last change. I will open the bleeder screw (on top) and pump it before starting again and see what happens, or if fuel is even there.

BTW... Am I being too aggressive w/tranny? I guess old habits die hard.:(

It appears from your sig that you are running stock programming. I wouldn't have the slightest worry about your ally. She'll run for years like that. If you want a little more piece of mind put in a transgo jr, for good measure, and then add a 100 hp with a tuner. You'll be glad you did.

E

my truck was doing the same thing and i replaced the water sensor and cured the problem.....i had actually gotten worried i had bad fuel,so i replace the filter while doing so i noticed it had been leaking. i ordered a sensor and it fixed all my prolems

my truck was doing the same thing and i replaced the water sensor and cured the problem.....i had actually gotten worried i had bad fuel,so i replace the filter while doing so i noticed it had been leaking. i ordered a sensor and it fixed all my prolems

That's good news. I'm still under warranty, so I should be able to replace the leaky sensor for free. Right now, I'm pretty stressed about it as I only have @14,800mi and want to keep the truck for 200,000 or so. I bought it new and was very surprised to have a problem this early. I will show the leak to the tech next week and hopefully not have to leave my truck at the dealer over night.

Thx,
Jason

That's good news. I'm still under warranty, so I should be able to replace the leaky sensor for free. Right now, I'm pretty stressed about it as I only have @14,800mi and want to keep the truck for 200,000 or so. I bought it new and was very surprised to have a problem this early. I will show the leak to the tech next week and hopefully not have to leave my truck at the dealer over night.

Thx,
Jason

The leak will cause the exact symptoms you mentioned. mine did the same thing. the reason it falls flat at higher RPM's is because it is starving for fuel. You can simulate high pressure by priming the fuel filter. You should not have fuel leaking out if the system is good. Also before you start the truck, prime the filter. I bet it fires right up.

When mine did this I also noticed it ticked louder than normal. Almost sounded like rod slap.

Right on guys... it was the WIF sensor. I have a new one now under warranty. I'm surprised that more people haven't had this problem. We'll, I'm not "breaking the seal" on this one. The dealer tech told me that he has replaced two lately. Neither were cracked, just started leaking from the valve. I'm going to keep an extra around after the warranty is up. Hopefully this thread will be easy to find when others encounter this simple repair issue.

Thx again!
Jason