03 Yuk XL slight idle misfire

[sidewayz0]

So to set the scene: My truck died a few months back from having a loose Power connection on the battery. Slowly dying until it didn't start. Silly me overlooked such an obvious issue. tsk tsk.

Anyways, I threw a nice new battery in there an was able to limp the big guy home but noticed that I was having some awful issues. I was throwing a TPS code, random misfire, and an O2 code that's been thrown since 2003 (when we bought the truck). Now at 265k miles, I assumed that the janky connection may have tipped the boat on some old original parts.

So I started with the TB unit. I know, a little over kill but I had the extra scratch and really love the truck so replacing the new TB was chosen over unriveting the drive-by-sensor area, replacing, and cleaning TB. It ran better....but was still not able to drive. The TPS code left and now kicked up a MAF code. So I decided "Hell, may as well get a new MAF too for ol' Big Blue". The truck was slowly getting better but just not quite there. I replaced the spark plugs and wires and fuel filter (that damn 8th cylinder..). Still, didn't trust it past my driveway. I finally caved and a shop told me my fuel pump was dead. I think he said 15psi of the 50 or 55 I need???!! Again, ashamed I overlooked but here we are.

tldr; The truck runs and drives great after about 10mph. The fuel pump, filter, MAF, air filter, TB unit, spark plugs and wires are all BRAND NEW. The idle feels like a slight jump or misfire but isn't kicking a code. It's more of an annoyance than anything. RPMs barely move. I've exhausted my mechanic skills and would like to avoid a trip to a shop if it's something silly. The only thing I can think now is coil pack? Maybe something shorted when the battery was fritzy?

Thanks in advance. Enjoy my novel.

 

[01ssreda4]

You need to take it to a mechanic instead of continuing to waste your money.

 

[95escahoe]

You need to take it to a mechanic instead of continuing to waste your money.

X2 on that, had a similar issue on my truck ended up being intake gaskets


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[sidewayz0]

The truck was taken to a mechanic which is how I ended up replacing the fuel pump. Seeking experience in the issue that may spark ideas on the source of the problem not another trip to the mechanic.

 

[mitchn06]

Knock sensors corroded?


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[Tahoebigdog03]

Had some what of the same issue with the reduced engine power message. I changed intake gasket cleaned TB, K&N filter now good to go.

 

[cmc76]

i had some symptoms very similar. But i had an injector code. Ended up being a bad #6 injector. which after some research seems to be pretty rare.

 

[retiredsparky]

It is impossible to troubleshoot even something as simple as these gas engines over the internet. The above recommendations to take the car to a mechanic really meant "take it to a qualified mechanic".

Probably most of the repairs done so far are advisable at whatever your mileage is, since these vehicles tend to wear out the little things long before the big things.

So you can continue to do more of the same like intake gaskets, knock sensors, fuel regulator, various sensors, coil packs etc. But if you would like to repair what is wrong with it right now, rather than prevent future failures, go find a shop that knows how to troubleshoot (even the problems that don't cause a code).

 

[01ssreda4]

Even if you do the repair yourself, sometimes for hard diagnosis its worth it to get the proper one so you make just the needed repairs and nothing extra chasing a problem.