I have a 96 tahoe which is idling rough. I did a full tune up and it still does it. What else could it be?

Question

I was told it was because one of the cylinders wasn't getting enough presure. That I need a new engine. So I did some reading and it sound more like a fuel injector problom to me.

Answer 1

Check the EGR valve for carbon build up. Sometimes the valve will get stuck partially open from a piece of carbon lodged in it. It is easy to remove and check.

Answer 2

Well, first thing you need to do is figure out which cylinder is not firing.

1) With the engine cold, start it up and let it idle for 30 seconds or so.
2) turn off the engine and squirt some water or glass cleaner on the exhaust manifold to see which exhaust port is still cold.
That cylinder is not firing.
If there are two cylinders that are still cold, swap out the spark plug wires.
It's possible that you got them switched durring your tuneup.

If that doesn't help, look and listen for a vacuum hose that may have come off a vacuum port on the intake manifold and is sucking raw air causing a misfire.

Answer 3

Not really enough info here. When you say one cylinder wasn't getting enough psi. Does that mean the compression is low on that cyl? many things can cause an engine to idle rough it could be a vacuum hose off, a plug wire bad depending on the ignition system it could be a bad coil many things, water in the gas, bad gas you get my point.Was plug wires and fuel filter part of your tune up? Make sure the wires are not crossed if you did
change them. Good Luck

Answer 4

Try a http://www.BGprod.com BG44k engine cleaning service

Also, Chevron Techron

http://www.chevron.com/products/prodserv/fuels/additives/concentrate_plus.shtml