2003 4.7 Throwing P0302 Code ADVICE!!

[gearhead]

Hi Guys,

I have a 2003 4.7 2wd. A few months back the truck threw P0302 code. So I thought lets eliminate the obvious first. Checked the plugs and they were nubs! I had no idea this truck had copper plugs and it went 60k on factory plugs. I swapped them out and cleared the code and it was gone...for about 6 months. Well, now it is back, same code. So I though maybe it is a coil and plugs were just by chance bad as well. I swapped the #2 coil with #1 coil, cleared the code and waited to see. Well, it popped back up and its the same code, so not a coil.(Damn!)

Info on the truck: I am second owner, truck has 71,000 on it now. This ruck sat for about 5 years while owner was in jail, or so I am told. Since it sat for so long it does have a noisy lifter on start up but that's about it. I have found if I don't turn the key and let the fuel pump run it has a very hard time starting. It has been this way since I have owned it, so I just always let the pump run first.

The latest: The only thing I can different is every now and then if you are sitting idling you feel a miss. Feels like a quick kick where the truck gives a little jolt. RPMS on dash don't seem to move its just a slight miss that you feel. Other than that, no issues.

I need your help with this, let me know if anyone has any experience or can think of anything. I had thought it could be fuel related from sitting so long or maybe a clogged injector but kind of weird to be only one cylinder throwing a code. Let me know what you guys think, I hope this is enough info to fill you in and get the juices going! Thanks!

 

[RonJon '06]

Have you tried cleaning the fuel injectors? If the injectors are clean and you're still getting the code you could try swapping injectors like you did with the coil packs. Also check the wiring. If that all checks out then I would suspect a bad lifter.

 

[Redtruck-VA]

Letting the truck set for long periods of time, especially with the gas tank not full causes corrosion and usually the gas gauge doesn't work. Your truck sounds like it is losing it's prime. I'd suspect the fuel regulator and start by checking fuel rail pressure seeing how fast the pressure falls off after shutting the engine off. And of course what the rail pressure is while running.

 

[gearhead]

Thanks for the advice. I am going to pull the plug to and that should tell me something. I keep thinking it is something electrical since it is such a slight miss and so random. I would think if it was a lifter or fuel injector it would be constant I am also going to get my hands on my buddy's scan tool this week so I will keep you posted as I find things out. Any other ideas please feel free to chime. No bad ideas here.

 

[gearhead]

Just an update on this issue. Pulled plugs. The one plug from the bad cylinder for sure was lighter in color and was missing the distinct burn mark the others had. I pulled the injectors and sent them in for be gone through and flushed the fuel rail. I will putting in new plugs and checking the rail pressure as soon as the injectors are back. I will keep you updated with what I find and hopefully this thread can help someone else out in the future.

 

[gearhead]

Got the injectors back and the one injector was faulty at idle so it was replaced. Everything installed again and truck runs like a top again! Starts instantly and runs smooth, seems to have a little more juice. Hopefully this thread can help someone else looking to solve this code issue.

 

[xb1230]

I do get the same little jolt every now and then at idle, but never have gotten a code like you did.

I lately ran a half tank with some Royal Purple Injector cleaner and it did soften up the idle as well as helped a little in regards to fuel economy. Since I found some replacement studs for the Coil packs I'll be doing my Spark Plugs in the next few days.

Looking forward to see if this will change anything in regards to the jolt.

 

[gearhead]

For sure. Depending on your mileage it doesn't hurt to get them sent in and done at a local shop. They come back brand looking. Here in AZ I got them done for 18.00 per injector and had them back same day. I hope yours smooths out. I have heard of crank sensor causing some idle issues but who knows with all the sensors these days.

 

[royboy88]

Not tryin to jack your thread but xb1230 where did you find the replacement studs for the coil packs