My engine has a rough idle can I fix it?

The problem sounds very reminiscent of what my truck was doing. Turned out to be a MAF sensor. Here is the location so you can replace yours. Check out the diagrams (Below). Please let us know what happens.

The #5 fuel injector was bad for me. This guide help me find it.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Nice work, we are here to help, please use 2CarPros anytime.

My silverado was doing the same thing, where it felt as if the engine was getting choked, and died randomly. finally got to the point where it died on the highway, and wouldn't start back up. Replace the fuel pump, made a huge difference on mine. The job is not that difficult, the best way by far is taking the bed of the truck off, which is only held on by 8 bolts.
Mine still idles rough, but never dies, starts every time, and has more power.
hope this helps,

Rough idle whether cold or at operating temperature. P0300 code sel light is on. I have repaired sever vacuum leaks, replace the intake gasket, removed and cleaned fuel injectors. It had a bad fuel pump, so it was replace along with filter. Truck accelerates nicely and has plenty of power, it just idles rough. Bank 1 has random misfire and is lean according to long term trim. Short term trim is normal. The lean factor occurs once it has warmed up slightly to approximately 140 F. Fuel pressure is good but leak down is kind of weird. I have done several leak down tests and some of the tests have held tight with no drop for fifteen to twenty minutes. While other tests have dropped as much as 30 psi in less than five minutes. I got a bald spot by scratching my head on this one.

Have you checked to see if the EGR valve might not be closing all the way, possibly due to carbon chunks getting caught in the pintle.

No I have not but would that cause problems only on bank 1? Bank 2 is good random misfire is only on bank 1. Will try EGR first thing today. What would cause problems only on 1 bank and why the weird leak down tests?

How would you know it is only happening on Bank 1? P0300 does not specify any certain cylinders.

I took the truck in to have it diagnosed and was told that bank 1 has random misfire cylinders 1, 3, 5, and 7 but could not find the cause of the misfire. They suggested that I have the engine tore down to see if it is a mechanical problem.

It could. It depends where the valve is located. A bad vacuum leak in that area could also do that. A stuck open EGR would also be a vacuum leak.

Any ideas on the fuel pressure leak down tests being so inconsistent? did repair leak at egr pipe, was a big one. Did smoke test after repair and found nothing else. Is there somewhere else I should be looking for a vacuum leak other than on the engine.

The fuel can leak either through an injector into the cylinder, though the regulator into the return line or back through the pump into the tank. If you are sure you have a lean condition, that points away from the first one. Check the vacuum line on the regulator to make sure there is no fuel in the hose. A regulator problem wouldn't be intermittent but the check valve in the pump could be.

Okay, no fuel in vacuum hose to fpr .Pinched off return line and did another leak down test first two tests were tight, waited for about twenty minutes the did another and pressure dropped about 12 psi in four minutes. Fuel pump is new about three weeks old. If I do a pressure test of fuel supply line will that work for checking the check valve in the fuel pump? Thanks for helping.

Instead of pinching off the return, pinch off the feed between your gauge and the pump after it has built pressure.

Make sure you do not pinch any plastic lines. Rubber only.

Hello,
I have a 2001 chevy silverado with a 5.3 liter when i go to stop real fast or when i have the truck in reverse and backing up it wants to stall and dose some time the idle drops very low also it surges I have replaced the fuell filter plugs wires pvc valve also throttle position senor it also has traction controll please help

I have also taken to the shop as to where they tested the fuel pressure and all sensor and they could not find a problem with my truck or as they put it they know there is a problem but they dont know what it is

hello, sorry about the long delay in answering. Should I get a new MAF? it seems to run better when disconnected.

Yes I would

OK, will check for that rubber section. If I pinch off the feed how will that work on the fuel pump check valve?

If you build up pressure and then pinch off the line between the gauge and the tank, you are blocking off the check valve.

OK, thanks for help.

For rough idle the first place I go is a compression test becasue low compression shows up first at idle.

Here are two guides that can help us find out what the problem is.

https://www.2carpros.com/articles/how-to-test-engine-compression

and

https://www.2carpros.com/articles/engine-vibration-at-idle

Please let us know what you find. We are interested to see what it is.

Cheers, Ken

Hi Ken, well the check SES light turned off on it's own without any more repairs. The idle is still slightly rough but has noticeably improved. When I had the diagnostics done a compression test was done and I was told compression was good all cylinders. The SES has been off for more than a week so I think I will leave well enough alone for now. Thanks for all the help.

Good to hear, please use 2CarPros anytime we are here to help.

Cheers, Ken

My Chevy Silverado stars fine, but idles a little rough. When I apply the gas, or put it in gear, the engine sounds like it's bogged down and it shuts off. We just replaced the EGR valve, but it hasn't made a difference. Do you know what could cause this problem?

If your check engine light is on have the computer scanned for codes.
Also check the fuel pressure. This could be a sign of a failing fuel pump.
Fuel pressure should be 55 - 62 psi

this guide will help us

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

I just changed the spakr plugs, and wires and changed the air filter and oil yesterday. Went out today to start it up and the engine is idiling really rough. Usually idles at 700 rpm, and this morning, it would spike at 1,000 and then surge and try to find a idle speed and then it would die, Any help???

Hello, did you have this problem before you worked on it? Maybe you knocked a wire/connector loose or a vacuum line? Can you check for codes?

I did ot have the problem prior to Saturday. I will look everything over again, but I did not see anything that was loose. I hooked a code reader up to it and it said pass. so I do not know what the problem is.