I just got done replacing the right side head on my 2000 Excursion.
The job went fairly smooth. New (used rebuilt PI) head bolted on with new bolts, new gaskets, new COPS, new plugs. Put it all back together and it started right up. Nice and quiet. Took for test drive and it has no power. After about 20 minutes it threw the check engine light. I pulled the codes and got the following:

PO174 Too Lean Left Bank
PO301 Cylinder 1 Misfire
PO302 Cylinder 2 Misfire
PO306 Cylinder 6 Misfire
PO307 Cylinder 7 Misfire
PO309 Cylinder 9 Misfire
PO310 Cylinder 10 Misfire

On the above cylinders I can pull the cop plugs on each (individually) and it doesn't change the tone or idle of the engine. If I pull them all together it does eventually drag down the engine. More-so if I pull the injector plug-ins for those cylinders. The plugs are firing. I have switched back and forth between known to be good plugs and COPS - makes no difference.

I have good compression in all cylinders. I have no vacuum leaks. (yes I checked all connections, the pvc elbow at the TB, etc.)

I have not checked fuel pressure, but I will tonight when I get home with a new gauge. It's possible I guess, but fuel pressure was not an issue before I swapped the head.
I keep comming back to the cam timing as the culprit.
Here is what I know for sure on the cam timing. (I think I did it right)
(1) I used the original timing chains - Probably should have replaced but with 78k on the motor I didn't. I regret it now.
(2) I used instructions from a Chiltons manual that were a little vague.
The manual states that if the shiny links on the chains are not visible, to split the chain equally and mark the links at opposite ends. One problem is the chain does not have equal lengths. I used someones advice on here and marked 1 link (the odd one out) then marked the two equal links at the opposite end.
With #1 at TDC I put the single link on the crank gear mark (aprox 6 oclock) and split the double links over the mark on the cam gear (aprox 12 oclock)
The chains guides and tensioners are routed per the manual.
Before I buttoned everything up, I checked, double checked, then checked again to make sure all marks and links were lined up correctly. Unless I just missed something that was not mentioned in the manual, I'm confident I did this right.
(3) I can unplug the cam sensor and it seems to have no effect on the motor, but it does immediately throw a cam sensor code.
(4) Unplugging the crank sensor kills the engine.

Other notables:
The vacuum line to the fuel regulator is hooked up. When I disconnect it I get plenty of vacuum through the line. I really can't rule out fuel pressure until I put a guage on it, but I never even unhooked the fuel lines from the intake. I just moved it to the side when swapping the head. I don't see anything pinched but it's hard to see anything behind the TB.

I guess my reason for writing all of this is I am hoping someone has a better idea of where to look next. Short of pulling the front of the motor back off, which I'm not opposed to doing, but I would like to be a little more confident that that is where the problem lies, I'm open for suggestions.

I'm really kind of impressed with how the pcm handles things. It must really be working hard to correct something thats wrong. To anyone who didn't know better, this thing doesn't sound like anything is wrong with it. It sounds like it has a very slight "miss" at idle. Until you drive it and get into the gas it doesn't drive bad, but under load the shift points are screwy and it struggles to make it up a steep grade.

Anyways, Any advice is much appreciated!

Thanks

Rob

 

Well, pull both valve covers and see if both cams are in sync. For instance, turn the engine over to TDC on compression stroke on #1, check where the cam lobes are. Turn engine over exactly one turn, and check #6. Should be the same.

But somehow, that might not be the problem you're thinking about, you think you did BOTH cams wrong? Or did you just take off the passenger side and didn't play with the driver's side? If so, do the above check and see what you come up with.

It should be possible to figure out, with the valve covers off, if something is amiss. I haven't timed a modular (yet), so I'm not sure what to be looking for and don't have the time to read the service manual (yet)

 

Ok, my curiosity got the better of me - without pics, here's the service manual's statement from 2001:


µ 30. If the copper links are not visible, mark two links on one end and one link on the other end to use as timing marks.

µ 31. Loosen the special tool on both camshafts.

µ 32. Install the timing chain guides.

µ 33. Rotate the LH camshaft sprocket until the timing mark is approximately at 12 o'clock.

Rotate the RH camshaft until the timing mark is approximately at 11 o'clock. Tighten the Camshaft Holding Tools to maintain camshaft pre-positioning.

µ 34. CAUTION:
Unless otherwise instructed, at no time when the timing chain/belts are removed and the cylinder heads are installed is the crankshaft or camshaft to be rotated. Severe piston and valve damage will occur.

CAUTION:
Rotate the crankshaft counterclockwise only. Do not rotate past the position shown or severe piston or valve damage can occur.

Position the crankshaft with the special tool.

35. Remove the special tool.

µ 36. Install the crankshaft sprocket and lower end of the LH (inner) timing chain, aligning the timing marks.

µ 37. Note:
Make sure the upper half of the timing chain is below the tensioner guide dowel. If necessary, use the Camshaft Holding Tool to adjust.

Note:
If necessary, adjust the camshaft sprocket slightly to obtain timing mark alignment.

Position the timing chain on the camshaft sprocket with the two copper chain links and the camshaft sprocket timing mark aligned.

µ 38. CAUTION:
The camshaft sprocket can jump time if the Camshaft Holding Tool is not secured.

Note:
Be sure the copper chain link and crankshaft sprocket timing mark are aligned.

Note:
The lower half of the timing chain must be positioned above the dowel.

Position the RH (outer) timing chain on the camshaft sprocket.

39. Note:
If necessary, adjust the camshaft sprocket slightly to obtain timing mark alignment.

Position the RH timing chain on the camshaft sprocket. Make sure the two copper-colored links align with the camshaft sprocket timing mark.

µ 40. As a post-check, verify timing mark alignment.

µ 41. Note:
The LH timing chain tensioner arm has a bump near the dowel hole, for identification.

Position the LH and RH timing chain tensioner arm on the dowel pins. Position the timing chain tensioners, and install the bolts.

 

Thanks Krewat. Thats what I did. My only thought is that maybe the chain slipped when I was installing the tensioners. I am going to pull the front end off tonight. It's one of those piece of mind things. I did check fuel pressure last night. 35 idiling and 42 when the vacuum line to the regulator was unplugged. So I can rule that out.

 

I'd pull the valve covers and see if you can figure if it's timed right BEFORE going and pulling off that front cover

Especially since it sounds like you didn't remove the driver's side chain, just the passenger's side? Check if both cams are in-time with the "set #1 to TDC on compression, check lobe/timing-mark position, rotate exactly one turn, and check #6".