Ok, Here comes the world's longest post, so please bear with it, I'm drastically in need help. The truck is a 2001 F250 Crewcab 4x4 with a V10.

Everything started out a month ago, I ran the engine a little too hard, and ended up spinning a bearing. Truck had 150,000 on it, and it was just time for it to go I suppose. Needing it back on the road quick like, and not wanting to put in a used engine that had 100K on it, I went for a new engine from Ford. The old engine still ran like a top, except for when it got up to temp, it lost oil pressure at idle. After driving for a while, it would lose oil pressure when cruising below 1500 RPM. Other than that, it still ran smooth as a top, no hiccups, nothing.

I put the new engine in, everything was going great. No real problems cropped up during the swap, which is amazing for my luck. The new engine included everything valve covers to oil pan, excluding the intake. During the engine swap I installed new plugs because its cheap and I was there. I wanted to replace coils, but couldn't justify 500 bucks when they were running fine previously. Got everything hooked back up, popped the fuel pump fuse, cranked for a minute to get oil primed, and put the fuse back in. Fired it up, and it started like a champ.

It was at this point, while my hopes were the highest, that things started to go wrong. I noticed right off the bat that it had a definite miss in it. I immediately thought bad COP. I've always read it was common on these, so I tried to troubleshoot, even though I thought they should be good, since they ran just fine two days earlier. So I started unplugging them one at a time, to try and see if it changed the idle or stayed the same. After unplugging every single one of them individually, not a one changed anything. This ticked me off, so I unplugged several at the same time. Still no change. Obviously it's somewhere else. I tried the same troubleshooting with the fuel injectors as well, only to get the same results. No matter which I unplugged, it never changed the idle characteristics.

At this point, I started to double check everything. I went over every single electrical and vacuum connection I could find, only to see everything was plugged in the same as before. This cant be. Check it all again. Still finding nothing out of place. What now. How about the MAF. I unplugged it while running, and the engine instantly smoothed out. Previous experience has told me that this indicates a bad MAF usually.

By this time, the MIL light had turned on. After reading the codes, I got a Bad Intake Air Sensor, as well as Bank 1 lean and Bank 2 lean. Since the intake air sensor is in the MAF, I decided a new one was needed. After a trip to the parts dept., there was a new MAF residing under the hood. Fire it up... No change. Damn. Oxygen sensors are also a cause of both bank lean conditions, and having 150,000 on them, I figured it wouldn't hurt the gas mileage to change them out. Swap both out, and still no change. What now.

After giving it a day to think about it, I was still coming up with nothing. Talked to a mechanic friend, and he said it was very common for the elbow on the PCV line going to the intake to corrode and break down. A large vacuum leak would definitely explain the poor running at idle.

On a side note, when driving, or even sitting still, get the RPM's above 1300 or so, and everything seems to smooth out, and it runs fine

I had already changed the pcv valve with the new engine, so I thought maybe moving the tube around might have broken it if it was on the edge of life. Pulled it off, and checked it, and it looked fine. Went ahead and bought a new line, just in case it had a hole in it, but no change. I'm lost at this point. I checked the intake bolts just in case there was a vacuum leak there. There was a couple lose, so I went over the torque pattern again, making sure they were all up to specs. Again, no change. I also went over all of the coils one by one, pulling them out, and inspecting. I pulled each one, looked over the boot, and stretched the spring just a bit so that it got back down to the end of the boot. I also checked the resistance on the coils and fuel injectors, and all were within an ohm or two of each other.

I am at my wits end here, and have to get it running right. It is eating through gas at like 7-8 MPG, because it thinks it is running lean, therefore dumping fuel into it. Today it started a new problem that is a result of this. As I was turning into a parking lot, it decide it wanted to die, leaving me with no power steering. I don't know if anybody has tried to man handle one of these trucks with now power steering, but let me tell you, it ain't fun. Had the little lady been driving it and not me, we would have broadsided a car that was sitting there waiting to turn out. Before it was just an annoyance that I wanted to fix soon. Now it is a safety issue that has to be fixed now.

I will accept and try any suggestions that you give. Please help a brotha out.

 

Dude, hats off to you for doing it yourself.
So what were the actual code numbers?
From what you described the Mil went off after you unhooked the MAF that was maybe what set that?
Were there codes present before this.

After the battery is unhooked Keep alive memory is erased. When you rehook the battery and start up the engine, Trim settings on fuel and spark need to be relearned. This could take up to 15 min at a [rough] idle. Then a couple of drive cycles to fine tune the driving experience.
On a side note how much for the engine?

Come out and play boys

 

Good thinking that the PCM needs to relearn things. I would do a drive cycle as outlined by Ford. (It's in here somewhere...I know because I posted it. )

Rough idle may point to the IAC...although usually when they're bad they won't let the truck idle without your foot on the gas pedal. Worth a look I suppose.

 

It sure sounds like a intake manifold leak to me. I would spray some carb cleaner around all the gasket areas and see if you hear a change in the way the motor runs. Also check and make sure that the new motor has the PI heads and not the 99 and older ones because they changed the intake configuration when the PI heads came out, some one may have sent you the wrong motor.

Denny

 

Yikes, I was trying to be reassuring, all that sounds scarey.

I have reset the PCM by the negative wire off technique and have never really experienced the engine running poorly until it relearned things. but I've never swapped out to a new engine.

Phreaky please tell us what you discover. It sucks being left limp.

I can't remember if my memory used to be better or not.

 

hi, you said you put in new plugs ,what kind ? v10s don't like bosch or the spilt ones. motocraft and autolite bseg barry /ge k

 

Thanks to all with suggestions. To start at the top...

I do believe there were codes before I unplugged the MAF. I'm trying to go off of memory, as I swapped the engine back on memorial day weekend. I think the IAT code was caused by unplugging the MAF, but after replacing it, and resetting the computer, only the Bank Lean codes came back. I think they were 171 and 174 for those. Replacing the MAF did not fix those, so I continued with troubleshooting. I replaced the oxygen sensors, and reset the computer, codes came back later that day. In all, I think I have reset the codes 5 or 6 times in the past weeks.

I too thought IAC, but after talking with several people, according to what I hear, when they fail, it just doesn't run without your foot on it. There isn't really a halfway failed with them.

My next thought along the process was also intake manifold leak. Looks like I left that part out of the story. I took the entire manifold off a couple weekends ago to check. All of the Intake to Head gaskets were fine, they came new on the engine. I also checked the throttle body gasket, and it also looked good. I then decided since I was there, I might as well check the lower intake gasket. Took it off, and it also looked fine. They were all rubber o-ring type gaskets, so its real tough to make them not seal I would think. Put it all back together, reset the PCM, and codes came back later in the day. I did make a point to check and look for PI heads when the engine was sitting on the crate.

As for the plugs, I always go with Motorcraft on plugs and filters. The engine ended up running 3075.00 or so straight from Ford. Then there was the $1000.00 core charge. They really want them back. What's really killing me is that this isn't my first rodeo. I've swapped many engines, and never had as much trouble as this. I didn't even have this much trouble when I swapped a fuel injected 351 into my V-6 Mustang.

 

I personally think you still have a COP problem. At idle, alot of times unplugging them does not change the idle too much or at least not enough for you to recognize a difference, especially if the COP hasn't entirely failed. Every time one of mine died I had to put the engine under load to make it miss, at idle it ran fine. IMO you may want to try purchasing a new cop, start it on whatever plug you like and drive it, if it doesn't go away, move the cop you removed as you know its still good, to the next plug and so on until your miss goes away.

Your lean codes could be a fuel filter or pump, I had to replace a pump in my buddy's v10 truck for the same issue you're having with the lean codes. Auto Parts Fast at RockAuto had the best pump for the money.

 

I still have COP in the back of my mind, but the codes would mean there is one bad on both sides. Whats the chances of that being the case. I also thought fuel pump. I put a new filter on with the swap. Threw a gauge on it, and got 30-32 psi at idle.

 

Get the misfire counters read, that'll tell you if there's one cylinder or multiples that are missing.

Sounds like a vacuum leak with BOTH banks showing lean.

Double check the PCV vent side tubing (from the other valve cover to the air intake tubing), IAC hose, everything between the MAF and the throttle body.

After that, definitely start checking for an intake leak.

 

Exactly what I was going to post as a reply. Had a code come up on my 98 E350 club wagon van with the 6.4L V-10 at Autozone (they do free code scanning) which at first told us it was the MAP sensor. Van was running extremely rough. Changed it out, no change. Then the code was telling us lean in bank 1 and 2 which usually indicates bad oxygen sensor or in this case, sensors since there are two. Changed both of those out, no difference. At that point figured it had to be a vacuum leak, and so with a can of carb cleaner and some detective work, I was able to track it down to the intake hose right blow the intake that had a HUGE tear in it. Replaced it and engine ran fine.

 

On first read through, my initial thought was two COPs are switched. I would closely recheck that wiring configuration.

 

Lean in both banks 1 and 2 indicates a vacuum leak. Like The CandyMan said, get yourself a can of carb cleaner and start spraying all vacuum lines and intake gaskets. Just make sure you do it when the engine is fairly cool because carb cleaner is flammable. The carb cleaner worked for me when I installed my supercharger. After I got it installed and all checked out I started it up and minutes later I got the lean bank 1 and 2 codes. I found my leak right away with the carb cleaner. There are vacuum lines all over that motor so check them all.

 

Holy old thread Batman. I've got her fixed. Here's an update for those who were playing along at home.

Finally got time to work on it again a few weekends ago. I tried the carb cleaner trick again, with the same results as before. Spray it around the intake, and the engine revs, no matter where you really point it. This has got to be one big damn leak. I had anticipated taking the intake to the machine shop, and having it decked, in case it was warped. About the only solution I could come up with. So I parked it, and started taking it apart. Low and behold as I take it off, what do I find...



Along with...



I don't know how I missed it before, but now that it's been run for a while, you can clearly see problems with the gaskets. If you notice the dirty spot, you can see the gasket plain cut off the corner of the ports. Three cylinders on each side had one heck of a vacuum leak. That would definitely make a difference in the running. Took the gaskets back to the dealer, and had a chat with them. The new gaskets came on the engine, so they decided they would replace them under warranty.

If anyone has wanted to see the difference between PI and Non-PI...



Not sure how I missed it when putting it all together, but she runs tons better now. There is still a slight miss at cruise that I am trying to track down. Fairly certain this one is a COP. And as luck would have it, I came across a heck of a deal last night. A local freight store that I go to just happened to have 10 Accel COPs on the shelf. They get damaged freight in from semi-truck wrecks, etc. I found out from an employee that they had 200 of them in stock, and I got the last 10. Walked out the door with them for 12 bucks a piece. hopefully this will relieve the final issues, and she'll be back to perfect once again.

 

Nice story - at least it has a happy ending

And rep points for reporting back!