powerranger262

I guess it could also be a TPS issue. Did you ever clean the MAF and Throttle body?

chetwynd

No I didn't, guess I can try that. Must be some threads about that here?

Especial86

iTrader: (1)

Prob another coil or 2.
if it feels like a driving on a washboard and it's bucking it's a misfire.. I'd just change out the rest of the coils..
Couldn't hurt to hose the MAF down too.. You can prob pull this off at auto zones parking lot if your on the road..

chetwynd

Yeah, crap, I mean I guess it could be more coils, but I'm not getting any codes, no check engine light, happens in both overdrive and no overdrive. $220 it's going to be just to have the ripoff dealership diagnose it, which I feel like is going to be a waste of money.

Let me give some more history:

1. Two weeks ago...sputtered as I pulled into the gas station, almost like it was running out of gas, after driving it from my house 10 minutes away. Died once in the gas station lot, got it restarted, didn't think I'd make it home, did. Replaced the fuel pump delay module or whatever it's called (above the spare tire), thought I had fixed it.

2. Last weekend...drove fine for first 15 miles or so, then a few jolts...then one or a few every couple of miles. Code reader said #5 cylinder P0305 I think, I replaced all 8 plugs and the coil for the #5 cylinder. Also replaced the fuel filter. Took it for a 20 minute drive, of which about 8 minutes was on the freeway, ran like a champ, thought I fixed it.

3. Today...truck loaded for a camping trip I've been planning for months, drove fine with no issues for first 25-30 miles...and while going something like 55-60 on the freeway about to cross the San Francisco bay bridge, I felt it jolt again and thought DAMN IT. Decided to keep going thinking maybe I just happened to downshift while going over a bump or something, but no, it started cutting out again. I wish I could describe the feeling...almost like it's running out of gas...jolting, cutting out, repeatedly. Then it would be fine for a mile and then again...jolting, cutting out, RPM drops a little when it happens, and sometimes the MPG display on my ScanGauge resets to 9999. Decided to turn back, and it just sputtered intermittently over and over the whole way home...sometimes to the point where it felt like it was just going to die on the freeway...which would have SUCKED.

Appointment at the dealership on Monday, but I really don't want to go down that path. I also can't deal with cleaning so and so sensor and then thinking it's fixed and find out 30 miles from home that it's not fixed.

I know there's no magic answer here...this is just ridiculous though, 32k miles on a 9 year old truck that I haven't beat to hell and a huge stuttering shudder that doesn't even generate a code.

powerranger262

I would think they would, but i would have them take a look at the cats also while it's at the stealership.

techrep

iTrader: (1)

still think you have some bad gas.. from sitting so much

Especial86

iTrader: (1)

Did you see any other black soot on the other plugs you pulled? It is more than likely additional coils that are the problem..
Accel sells a pack of 8 for $200 ish..

chetwynd

Not that I remember, but do these things really just go out after 32k miles or 9 years? I don't know, but I guess in my mind I would think that if another one or two were bad, it would just always run rough instead of intermittently. Would that not be the case? Like might they work perfectly fine until they get too hot or...? I mean the damn truck was fine for 25 miles, no hiccups or anything, and then just started doing it, and within miles was doing it like crazy. I'll probably drive it today again to see if it does it again, but I have a feeling it'll run fine and might only show the problem if I drive it again for another extended distance.

Bad gas...I ran it down pretty low and put in Chevron 92 last time I gassed it up...also put a bottle of Techron in it. Seafoam arrives tomorrow though.

I appreciate the help guys.

Especial86

iTrader: (1)

A weak coil can be bad under higher loads or more quickly timed firing events. It can work fine at very light cruise/idle, until you put a greater load of fuel/air into the cylinder, at which point the weaker, or intermittent spark won't be great enough to jump the gap of the plug to ignite the mixture completely. The longer you leave an incomplete burn, the more likely you are to melt down a cat (more problems). So "cheaping out" essentially, can sometimes lead to a long drawn out process of repairs that could have possibly been avoided from a full and complete tune up. Since you are quite clearly still misfiring, given the bucking and stumbling feeling, the ignition system is still showing a fault somewhere.

A bad coil boot on the plug could do it as well, you may have even damaged a boot spring while doing your plug change.
This is why I usually advocate changing all cops and boots if they are original.. This leaves 8 extra cops/boots to cycle in should newer cops fail down the road..
And yes, old cops and boots with low miles can still fail.
Age will affect hoses, belts, brakes, tires, air conditioning, paper filters, coolant, oil yada yada yada.. Low miles leaves no exemptions. In fact, low miles can actually be worse in the automotive world.. As the saying goes, if you don't use it, you lose it...

chetwynd

Ok, makes sense, thanks for the info. I'm just curious what makes you think it's an ignition problem as opposed to a fuel delivery problem? I'm not doubting your assessment, just trying to learn. Thank you!