Feels as if truck is missing at Cruising Speeds - My 2001 Silverado 1500 4x4 5.3 has 270xxx miles on it. It has had a Full tune up, new fuel ...

My 2001 Silverado 1500 4x4 5.3 has 270xxx miles on it.

It has had a Full tune up, new fuel pump, and fuel filter installed within last 5000 miles. While driving home and maintainig a steady speed of 60-65 mph the truck acts like it has a slight miss to it. I can speed up and truck performs fine but I can feel the miss in the Truck. The Check engine light is not on at this time. Any suggestions on what to check?

It might be a good idea to hook it up to a diagnostic tool. Just because the check engine light isnt on doesnt mean that there isnt anything wrong. I have had coil packs go bad without a check engine like coming on. It sounds like you probably have an issue with your ignition for sure. My friend had your exact same problem with his F-150 and it ended up being 1 coil pack. Hope that helps you out.

I forgot to mentione It has been hooked up and it showed a slight misfire at idle but Didnt point to anything in particular.. is there a way to check coil packs?

I'd check for a vacuum leake while you are at it.

What way would you recommend for vacum leak checks? Ive gave it a visual but can you recommend a better way? Any certain areas I should look?

Spray brake cleaner around the intake manifold and vacuum hoses to see if the idel speed changes. Also, if you have access to a diagnostic scanner that can access the live data it will show one (tell tale signs of one) as well.

I had forgot about the brake cleaner tirck but will try it this weekend.

Just gotta make sure engine is nice and cool. Worked in Auto pars store on time and Guy came in and Set the under side of his hood a blaze on his old car.. Motor was super hot..

Seems to me if it was a Vacum leak It would miss at all times but maybe not..

On a side note Sorry for all the Small questions but My hobby is racing ATVS.. AS long as the truck starts and drives im good. Know if you ever want to know about a Canam Atv I can answer dang near anything about them.. ( hence the name)

A bad leak on a 5.3 will act up mostly cold and at lower rpm.

We're the proper plugs put in?

Most quality Scan tools will read misfire counters on newer GM products.

Need to pin point what cyl is misfiring if at all.

Another quick check since its at freeway cruise speed is to drag your foot on the brake just enough to unlock the torque converter. If the miss felling goes away it could be the torque conveter locking and unlocking. If that's the case you are gonna be looking a whole different direction

canamchris wrote:On a side note Sorry for all the Small questions but My hobby is racing ATVS.. AS long as the truck starts and drives im good. Know if you ever want to know about a Canam Atv I can answer dang near anything about them.. ( hence the name)

Thanks for the offer, but I think I'll stay away from the atv's. lol.

Running AC irridium plugs

Can you explain what you mean about the TC?

Checked for vacumn leaks today and It had none that I found.

Also checked fuel pressure today and its holding 49 at idle and when you get on it. Is this enough or should it be more?

Thanks again for all the help