ejbrooks

I have a 2007 Ford F150 4.2L with 209,000 miles that I purchased about 2 months ago - when I first got the truck it would misfire a bit under acceleration but I did not think much of it because the check engine light stayed off and after running some Seafoam through the crankcase, gas tank, and vacuum lines it seemed to get quite a bit better and I put about 2,000 miles on the truck without any issues. I recently however have been driving the truck which now has a pretty severe misfire, especially when the engine is cold and started for the first time of the day.

I initially thought that the misfire was a jumping spark due to it being quite rainy and humid for the past few weeks. I did not think much of it because the CEL was still off and I assumed that once the engine warmed up and burned off some moisture the misfire went away and wasn't a big deal. But the misfire seemed to get a bit worse and definitely is not dependent on rain/humidity because the misfire remains the same regardless of it raining or being hot and dry etc. The misfire and hesitation almost always is the worst when I go out in the morning and go to leave the driveway it chugs along and until I get to operating temperature then I must gain the cylinder back because it runs much better and the shaking goes away. Once in a while the misfire will come back at operating temp but is less severe.

The check engine light came on last week and now it takes an excessively long time for the engine to even out and run normally - usually when it reaches operating temperature. I ran the CEL and saw a misfire code on startup as well as cylinders 2 and 4. So then I figured it was about time to finally do the plugs. wires, and coil pack (4.2L has one coil pack not COP coils like the 5.4L).

After doing the ignition service I turned off the CEL and the truck ran great for about 7 miles and I thought I might have lucked out with it just being a normal ignition issue. I then parked it for the night and went out again in the morning and the same misfire/hesitation remains. Within about 20 miles since the ignition service the CEL began to flash and I scanned it once more and the following codes were registered:

P0171 Bank 1 System Too Lean
P0202 Injector Circuit/Open - Cylinder 2
P0302 Cylinder 2 Misfire Detected
P0316 Misfire Detected on Startup (First 1000 Revs)
P2006 Intake Manifold Runner Control Stuck Closed Bank 1

Does anyone have any insight for what I can do to address this misfire issue? Other than checking for broken wiring at the injectors how else can I diagnose the misfire since I am almost certain it is not an ignition issue? Has anyone had these problems before and how did you fix them? I have attempted to do some reading but everyone has slightly different issues but point to other common problems such as MAF, IAC, Fuel Pump Driver Module, EGR ports in the intake being plugged, intake manifold runner control clips being broken etc.

ejbrooks

Looking for some further advice here! Any help or ideas are appreciated - I have to get this inspected in a month!

Based on my above posting I have cleared the codes and tried a number of things to figure out whats happening. I now have codes including:

P0171 Bank 1 Too Lean
P0174 Bank 2 Too Lean
P0302 Cylinder 3 Misfire Detected (moved from cylinder 2??)
P0316 Misfire Detected on Startup (First 1000 Revs)
P2006 Intake Manifold Runner Control Stuck Closed Bank 1
Once in a while I get EGR codes, or just one bank will be lean, sometimes both, and it seems to vary.

I have installed a new EGR valve, cleaned and checked the MAF sensor function (fuel trim readings are within spec +/-5 at idle as well as at 2500 rpm the PID fuel trim reading do not go above +5 indicating that my MAF is NOT faulty), I have done plugs, wires, coil pack, checked fuel volume delivery (fuel trim readings at idle are within spec and the readings do not change with increased rpm or load indicating that low fuel volume is NOT the cause of the lean code), I have sprayed all vacuum connections and intake manifold sections with starter fluid/brake clean on both a cold engine and a warm engine and get NO change in rpm indicating I do NOT have a vacuum leak.

Any idea what to check next? I don't want to throw any more parts at it - I do have an intake gasket set but want to confirm that is the issue before proceeding.

Let me know! Thanks!

TheRealBigWes

snowhite5oh

Have you guys figured out what it was?? I am seeing to have the problem now on my 4.2 with 214000 miles.

ejbrooks

I have figured it out! It has been good now for about 9 months and about 20k miles. I replaced the intake manifold gaskets, and intake manifold runner control clips that hold the rods in place on the back towards the firewall. I could not tell they were not working/broken until I pulled the intake off. To clear my EGR codes I did extensiveeee smoke testing and finally found a leak right at the EGR to intake manifold with the metal gasket, replaced that and the EGR valve again and I was good to go. While I was in there I cleaned up the IMRC flaps very well so that any carbon was not in the way. Let me know if that helps.

snowhite5oh

Thanks for the feedback! I also have had a coolant leak for a while but now its worse. Starts are harder and the power has gotten worse. It used to shake bad when cold and gas pressed then get better when hot but now it doesnt matter. It leaks coolant even if the truck is sitting. I think the coolant leak has sonething to do with the misfire and I was going to add some seafoam and replace the coil pack to see if it helped but after reading more forums it could be the front and intake gaskets. I had the cel finally come on today for a couple seconds then cleared. But my scanner on it and the only code is the cylinder 2 misfire stored. It's my work truck and I don't really have the time to work on it myself as I would love to do. Rear main seal has a good leak as well. Sorry if I'm all over the place.

ejbrooks

My intake gaskets that were leaking were consuming just a little bit of coolant but I do not think that was the heart of my issue or yours (unless it is leaking seriously). Upper gaskets/plenum gaskets were more concerning for my rough idle/misfire when cold that would go away when warm. This has to do with the IMRC clips and the functionality of the IMRC system etc. I also had already thrown seafoam at it as well as a coil pack, wires, plugs, etc and yeah the forums are right that is really not the reason for most cases (just easier to try so most people go that way hoping to get lucky.) The classic "spraying starter fluid on the intake to get idle to increase if there is a leak" theory really has never worked well for me so I invested in a $100 smoke tester I bought on Ebay and it really has helped me out a lot with a bunch of cars as well as this truck. Just a thought.

snowhite5oh

Hmm ok what do you think is the best option? I really dont think a new coil pack will help. Im adding about 2 cups of coolant a week maybe. Do about 60miles roundtrip as well to work. Did a tune up at the beginning of the year but didnt replace the coil pack.

snowhite5oh

Also my temp guage goes up close to high at times but no sign of overheating.

ejbrooks

Yeah like I said the coilpack and tuneup for me did nothing. I think you have a couple issues going on. I don't think a cup or two is too dramatic of a leak, you sure its not the heater core, coolant piping, radiator, leaking?