Hello,

So hopefully someone has time to read this, I don't know how to explain without a ton of writing. Im about to drive from va to mi tho so need to figure this out.

I have a 2001 5.2L with 101,000 mi. This truck has run great for the past year or so. After it sitting for about 3 weeks I get in and take off out of my driveway, as soon as I take off it feels like it lost power and ran rough/almost stalled then came back to life. When I got to a stop sign it idled a little rough and almost stalled. took off from there and truck drove fine, maybe a little less power than normal but it has been 3 weeks since I drove too so hard to judge. drove for about 20 min fine then on way home take off from a light and same thing weird power loss and almost stalled. Idled rough at another stop and fine at others.

So I get home go replace the IAC and TPS which I have replaced about a yr ago hoping that was it, go for a drive and same just random times. I came home pulled the tb off looked at plenum gasket and inside looks dry and good, cleaned tb. Checked fuel pressure right at about 48-49 shaking a little on the needle, while its sitting there idleing with gauge on after about 5 min starts idleing rough and actually stalls, I watch the fp gauge while this happens, no drop in pressure. take the gauge off and start it up, idles fine for about 5 min go for a drive runs fine. This is where im lost I couldn't make it do anything wrong tonight. Have been troubleshooting this for about a week, but have a big trip coming up so I figure Ill ask for help.

Also about 6 mo ago I did a major tune up replaced dist cap & rotor, plug wires, plugs, air filter, coil, all the normal stuff and have put prob 6k mi on it since then running good.

Anyone have any ideas or even a shot in the dark on this. No CEL, have not read it on a scanner, could there be any codes and no CEL.

Okay well thanks in advance for even putting up with my rambling on.

 

I can think of only two things, myself, front O2 sensor or a battery that's making the truck do weird stuff. Which has happened. lol

 

yeah weird is an understatement. Okay ive seen those two mentioned when doing research. I will def check that battery in the morning and prob just replace the front 02 sensor. thanks.

 

FWIW, replacing the battery in my truck made quite a difference in the way it behaved. It was weird, but it did.

 

Yeah I have a 07 5.9 as well and I had a few problems after replacing only one battery that was bad. Replaced both and all problems gone, its weird how they can do that and still read good on just a meter. This one should still be under warranty so ill take it in and get it tested.