Low RPM Stumble Hesitation Injector issue?

[blownshovel]

I suspect that I have 2 stuck injectors.
Idle/off idle miss that clears up at cruise
Cyl 7/8 have sooty plugs... At idle If I disconnect the Injector leads to the cylinders in question the motor RPM does not drop. The injector wiring is functioning properly and is "firing" but fuel is flowing even when the injector is unplugged.
Anyone have ideas or think I'm on the right track? Can they be cleaned at home... should I send them out or just buy new?

Looking for Opinions

Thx

[blownshovel]

I suspect that I have 2 stuck injectors.
Idle/off idle miss that clears up at cruise
Cyl 7/8 have sooty plugs... At idle If I disconnect the Injector leads to the cylinders in question the motor RPM does not drop. The injector wiring is functioning properly and is "firing" but fuel is flowing even when the injector is unplugged.
Anyone have ideas or think I'm on the right track? Can they be cleaned at home... should I send them out or just buy new?

Looking for Opinions

Thx

no opinions offered?

but an update to help someone down the road

I pulled the injectors out to verify what I thought... poor spray patterns and two pretty much stuck. I used varying chemicals to clean them ..eventually I had two that were very gummed up with gelled fuel. They took longer to clean up and I had to abruptly hit one of them with a piece of 2x4 to get it unstuck. After the cleanout the truck ran better.

[Jamest]

Run some seafoam in a tank of gas. I had oil problem with a turbo and got oil in the intake side of the motor. It ran like Sh*t, but after the seafoam it cleared up. Runs very smooth now. It will clean the injectors from the inside. Some people have poured it in the intake and let it sit. They say you will have a smoke cloud for about 30 mins, but it works.

Jamest

[blownshovel]

Run some seafoam in a tank of gas. I had oil problem with a turbo and got oil in the intake side of the motor. It ran like Sh*t, but after the seafoam it cleared up. Runs very smooth now. It will clean the injectors from the inside. Some people have poured it in the intake and let it sit. They say you will have a smoke cloud for about 30 mins, but it works.

Jamest

The motor came out of a rollover... oil was everywhere.. and plenty in the intake for sure.
I put 1/2 can seafoam via vacuum line and let it sit for 5-10 minutes, dumped the rest in the tank. Truck smoked for over an hour idling... I can still smell some nastiness in the exhaust.

[Tolliwacker]

Which vacum line did you use to get the stuff in the intake to sit?

I have a 06 5.3 that needs some attention.

Thanks in advance.

[blownshovel]

Which vacum line did you use to get the stuff in the intake to sit?

I have a 06 5.3 that needs some attention.

Thanks in advance.

I used the fpreference line. middle of the driverside of the intake. I just disconnected from the Fuel Pressure Regulator... had a small formula can (any short cup will do) about half the Seafoam was in the can. It sucked in and nearly stalled.. then kept running until it was all sucked in. The process took less than 10 seconds then I shut off the engine. I let it sit more than 5 minutes but less than 10. I poured 1.5 cans of Seafoam into the gas tank (@20-22 gallons in the tank). I let the truck idle as I worked on other things in the garage. It ran for almost 2 hrs before it stopped smoking.

You for sure want the truck OUTSIDE when you do this. It will smoke more than you can imagine.

[silverado06]

when you do an injector clean up with a kit you use the line running to the brake booster, and use the aeresol directly to the tb. Ive used one on my dads truck and it wouldnt even stay running. It runs nice now though! I dont think you can buy them though, i had to hit up one of my boys at jiffy lube.

[casey23]

umm...two "stuck injectors" would cause a hard start and long crank time... not going to cause the off idle problem your talking about.. Is your pressure regulator good i am sure?.. you didnt list any mods to the truck.. I am going to guess this ia 5.3L ? or OBS... 96-99 5.7 have injector poppet problems that will cause what your talking about.. but it will also throw a code for missfire...

[blownshovel]

umm...two "stuck injectors" would cause a hard start and long crank time... not going to cause the off idle problem your talking about.. Is your pressure regulator good i am sure?.. you didnt list any mods to the truck.. I am going to guess this ia 5.3L ? or OBS... 96-99 5.7 have injector poppet problems that will cause what your talking about.. but it will also throw a code for missfire...

'03 6.0l . I removed the injectors and cleaned them. Fuel had gelled in the rails and injectors from sitting several months. Truck runs much better now. The off idle and miss are gone.

Afterward I ran the Seafoam through the intake and fuel system.

[Tolliwacker]

Blown Shovel,

Thanks for the info, Could I go through the brake booster line with SeaFoam like stated below, or is it restricted to the injector cleaner kit?

This question can be for Silverado06 also, whoever wants to chime in...

and by the way, Nice Chevelle!

when you do an injector clean up with a kit you use the line running to the brake booster, and use the aeresol directly to the tb. Ive used one on my dads truck and it wouldnt even stay running. It runs nice now though! I dont think you can buy them though, i had to hit up one of my boys at jiffy lube.