Rough Idle

[FrankenChevy]

My 2001 Silverado has developed a rough idle. It feels like it is missing on one cylinder. I just changed the spark plugs, no change. I also just replaced the original battery.

 

I was thinking maybe a coil, or a fuel injector. I am not sure of the best way to troubleshoot.

 

It's a 2001 Silverado 5.3L auto trans. It's got about 110k miles on it.

 

 

Thanks

 

 

 

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[Carder09]

I kinda had the same issue but it only "studdered" every now and again. Good thing was it didn't affect any performance but I went ahead and changed all plugs and wires, both were due, and it turns out one of my spark plug wires was just sitting on a plug not fully compressed onto the spark plug. After all that, runs like new once more without any issues.

[txab]

Check for codes.

 

Clean MAF and throttle body

 

Fuel filter

Fuel pump pressure

[FrankenChevy]

Check for codes.

 

Clean MAF and throttle body

 

Fuel filter

Fuel pump pressure

 

 

Great ideas, I will be doing this today. I will post back with what I find.

 

 

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[FrankenChevy]

No codes.

 

MAF

 

 

 

Key on engine off fuel pump running. About 55psi

 

.

 

Key on engine off fuel pump off. About 52 psi

 

.

 

Engine running. About 48psi

 

 

Sorry about the focus, stupid camera.

 

Not sure how to clean the MAF, it looks kinda sensitive, I did clean the throttle intake.

 

Now I am thinking the pressure is a little low. I was thinking about a new regulator.

 

 

Thanks

 

 

[txab]

Use MAF approved cleaner.

 

Fuel pressure is low. Check pressure reg. for presence of fuel at vacuum line. Replace if fuel is found

[Krausmotorsports]

Check for codes.

 

Clean MAF and throttle body

 

Fuel filter

Fuel pump pressure

X2 I did this and it cleared my issue.

[FrankenChevy]

 

Use MAF approved cleaner.

 

Fuel pressure is low. Check pressure reg. for presence of fuel at vacuum line. Replace if fuel is found

 

 

 

Thanks Guys, I will do this and get back to you.

 

Great qoute in your sig, how true it is.

[FrankenChevy]

Just wanted to do a follow up on this.

 

The air filter was due so I put a new one in. Then cleaned the MAF, and installed a new fuel pressure regulator.

 

 

 

Well the truck idles much better now, it's not perfectly smooth but does not shake the whole truck like before.

I think what helped the most was cleaning the MAF. I replaced the fuel pres. regulator and checked the pressure and it was not much different then before. I also bought a new fuel filter but have not put it in.

 

 

Thanks to everyone for your help.

 

 

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