Ok, the truck doesn't get run too much. It's got around 177k on it. Starts up fine, I can pull out of my sub and accellerate normal driving speed on the local road (about 45). Say someone pulls out or I take my foot off the gas and I coast a little bit to go around a corner, then when I get back on the gas, not hard enough to down shift, it get a studdering miss. It's been doing it for a long time. I just might have to drive it up north with my sled and I want to try to find it now. If I stomp on it enough to downshift, it usually goes away (or becomes less noticeable.) If I slowly accelerate again, it usually doesn't do it either. I've recently replaced the fuel filter. In the past if I had a mis-fire (electrical) it seemed that the computer always threw a code. Does anyone have a suggestion?

 

I had a very similar problem. Took my truck to a local repair shop and had the fuel injection system cleaned out. They hooked something up to the fuel rail and cleaned everything out.

No more stumble after it was flushed/cleaned out.

Cost $50-$60

 

I may have to do that. I've run seafoam through the vacuum system and this last tank had a whole can in the tank. I'll admit this last tank hasn't been much of an issue and I was trying to induce it. I'll do some calling around. Thanks!

 

Try to FORCE your truck to do that for as long as you can. In order for your engine to throw a code, the miss has to happen X number of times over X time interval. So whatever is causing it, apparantly doesn't do it all the time. I would lean toward a bad COP, and the only way to know which one it is, is by doing what I said.... Do whatever it is that makes your truck miss, and keep it missing until your "check engine" light comes on. Then you'll know exactly what's wrong.

If it's a general problem, you'll get the code equilivant to "random missfire" But if you have a problem with a particular COP, injector, spark plug etc, your computer will narrow it down for ya, to a specific cylinder.

 

That's what I've been trying to do, however I don't drive the truck much like I used to. I've replaced a few coil packs and I used to carry a spare. It's much nicer when they go out entirely. It's alot easier to figure out the culprit.

 

Yeah, just go for a drive, and make it do it as much as you can. It will eventually throw a code.

 

dnale, just a thought but I have seen people call torque converter shudder a miss & that would explain why the light isn't on. On the other hand I have seen vehicles with a miss take forever to set a code. Is this a 5.4 with COP or a 4.6 with wires?

 

Yeah, it will do that really bad if you never change the trans fluid.

 

My 02 screw is doing the same thing. I cant get my truck to throw a code either. So your not alone

 

It's 5.4 with the COP's. I drove the crap out of it today and it's back. No code though. It's not the tranny. I've serviced the tranny and it's not causing the shudder. I'm debating about new coils and injectors (and plugs). Of course that's me doing it myself. I could be just replacing alot of parts chasing a problem. Does anyone know of a place to buy the injectors for a good price?

 

Haha when my truck started missing under a load, I put it in 2nd gear from a dead start and accelerated until it finally threw a code.

 

what was the culprit?

 

It threw a cyl. 2 misfire. Changed plugs/wires and it was good to go.

 

I drove it again yesterday and tried like you did, with it just in 2. No code. This thing is more stubborn than I am. I need to take it in for the recall on the cruise control this week and I might have them clean the injectors.

I'm wondering if the "cleaning" of the injectors makes them as good as new? Can an injector wear out?

 

Hook it up to a code reader that will read pending codes. The edge will, and the dealership's reader might too. You're gonna sink some dough in it chasing ghosts. You better wait until you get a code in your hand, or the dealership is gonna start replacing parts. They'll replace your air filter, fuel filter, injectors, spark plugs, change your oil, pump up your tires, change your blinker fluid etc.. And believe me, they'll charge ya for it too!