2005 LS V8 idle issue after taking intake manifold off

[mrdougiefresh1]

Hello, this is my first post. I have a 2005 LS sport model with just over 120k. After a few days work, I completed the cooling system overhaul and replaced all the plastics, degas tank, blah, blah. If you know anything about this. You have to take the intake manifold to get to one of the plastics. After reassembly, I proceeded to begin the cooling system bleeding process and got to the point when you start the car. To my surprise, the car barely held on the idle and a check engine light popped up soon after. You guys have any clue what I might have done to cause this? Also, I will post the CEL code as soon as my friend gets here with his scanner. Any help is appreciated. Thanks.

 

[LS4me]

Hello, this is my first post. I have a 2005 LS sport model with just over 120k. After a few days work, I completed the cooling system overhaul and replaced all the plastics, degas tank, blah, blah. If you know anything about this. You have to take the intake manifold to get to one of the plastics. After reassembly, I proceeded to begin the cooling system bleeding process and got to the point when you start the car. To my surprise, the car barely held on the idle and a check engine light popped up soon after. You guys have any clue what I might have done to cause this? Also, I will post the CEL code as soon as my friend gets here with his scanner. Any help is appreciated. Thanks.

Did you torque the intake manifold to the correct torque in the correct sequence? Sounds like an air leak.

 

[joegr]

There are a number of things that have to be disconnected and then correctly reconnected when you do this. Perhaps one was missed? The hard plastic vacuum lines can become brittle and very easy to crack or break apart. Did you check those, in particular, the ones to the EGR and fuel pressure sensor? Did you replace the intake manifold gaskets? Did you follow the factory sequence for the removal of the manifold bolts (to prevent cracking of the manifold) and for the re-installation and use the correct bolt torque values?

 

[mrdougiefresh1]

Intake manifold gaskets were replaced and torqued properly. I will check around to see if I missed reconnecting something but I'm pretty sure everything's hooked up. I'll write again when if I find something

 

[mrdougiefresh1]

After scanning the codes, I ended up with the following:
P0304
P2195
P2197

From looking, the first one is a cylinder 4 miss and not really sure about the next two. Car ran perfect before the manifold came off, so not plugs or coils. Any idea?

 

[joegr]

Check the connector on the #4 fuel injector. The plastic latches on the connectors are easy to break.

 

[mrdougiefresh1]

Pressed down on all the fuel injector connectors again, started it up again and the CEL went off immediately. It kept idle, but didn't have a chance to drive it around to see if the light came back on. Fingers crossed, I'll drive it tomorrow and check back.

 

[joegr]

Pressed down on all the fuel injector connectors again, started it up again and the CEL went off immediately. It kept idle, but didn't have a chance to drive it around to see if the light came back on. Fingers crossed, I'll drive it tomorrow and check back.

If any of the latches are broken, then the connector(s) will just pop back out after a short time. You can use zip ties to hold them together.

 

[mrdougiefresh1]

Drove the car today and car ran horrible again. Car is missing horribly and has extremely rough and inconsistent idle. I will try double checking the injector clips and tie any together that are broken as joegr said and will check back if anything changes

 

[mrdougiefresh1]

After taking a closer look, it appears I messed up seating the manifold and pinched the gasket in one spot. I just ordered new ones and will check back after installing them

 

[mrdougiefresh1]

Yup, I'm an idiot. Car is running amazing now with new felpro gaskets. To anyone that takes their intake manifold of, be very careful putting it back on as the gaskets like to move around.