ok, ive been clearing codes for my 5.0 in the runner so i can get it into the smog ref and registered. the only 2 i cant seem to clear are 41 and 91 both show a lean condition for each cylinder bank. ive run a pressure test and the pump is in range on the regulated side, a little low but still in range. checked all fittings for vaccum leaks and the intake tubes are sealed too. all other sensors are showing that there working. all ignition parts have been replaced too. seems like a fuel problem since they all show lean, maybe add a second fuel pump to regane any lost pressure might help. thats how some fords are done anyhow. any suggestions?

I know you haven't had it your runner very long but could your fuel filter be clogged or damaged? The one to get a hold of on that is Suzuki with the heat in the suzuki board hes into all the 5.0 engine conversion stuff and one hell of a driveability guy.

checked its clear

btt get his truck on the road

Have you checked the EGR system, I remember reading in Four Wheeler magazine that a clogged EGR valve will cause a engine to run lean. I think it was refering to a carburetor version, so I don't know if this will apply to a fuel injection system.

How many miles on the o2 sensor?

new o2 sensors, on both sides. but havent checked EGR yet.

TPS? that thing seems to have such an effect on the motor down to .01 of a volt. Check it out....make it .999 if you haven't already.

brand new TPS phil. non adujstable.

Originally posted by bigtoy22
brand new TPS phil. non adujstable.

it's adjustable...they all are...you may have to ream the holes a bit to make rotational room though.

ok i'll have to test it and see. also is your map sensor hooked up to a vacuum source

I don't think my anything is hooked to nothin' :D I haven't even tried to make it legal...I just know it runs perfect and fast :D

lol thanks i'll check it out

Does it run air injection? If so, could the diverter vavle be stuck open? What about an IAC being stuck as well?

yes it does. looks like i got some more to check out now.

One more question.....How is the idle. Does it roll up and down, or is it smooth?

smooth ive been helping him out and no that aint the problem :flipoff2:

Sanity check: Do they care if it runs clean? So I can appreciate it generating a code and you don't want it to run like this all the time, but if the question is only to get it smogged: A) Do they check the codes? (I've never dealt with a conversion like this where you've got the motor that's other than what was stock). B) If they don't, I'ld think that as far as smog is concerned, they'ld love it!

I know on my 84 stang (carbed, no computer) the bastards used to screw with the idle screws on the throttle plate to get it to pass, but wind up making it run like crap because it was so damn lean. I'ld then have to take it home and screw them back in before I burned out any valves.

when you take it in for cert. they check it all. and all codes have to pass. so makes it a big pain

update. i replaced all vacuum lines, new map/bp sensor, new temp sensor for computer, set tp sensor. still gotta check egr, but im too the point where its gonna have all new sensors before long and still no change.



code 41 reads (engine running) HEGO cicuit indicates system lean (right h02s).



code 91 reads (engine running) HEGO circuit indicates system lean (left h02s).

Originally posted by bigtoy22
when you take it in for cert. they check it all. and all codes have to pass. so makes it a big pain
Well not knowing a lot about ford but I know a little about FI. I would still be questioning the O2's. Some fords run 4 O2 sensors. 2 per side. The way it works is if both sets are within a certain range then the computer thinks all is well with the O2's. If they 2 sensors are showing a different reading then the computer starts throwing codes. Typicaly the first injector in line will be the one the computer is using to make the mixture adjustment from and the second is just used to compair the mixture the first is seeing.
Do you know if your's was originaly a 4 O2 set up and you just kept the main sensors that the computer makes the adjustment for? The reason I ask is there is only a couple of ways the computer can figure out the system is lean. The first is the double O2's per side giving different readings and the other is with knock sensors picking up detonation. Typicaly if it was a knock sensor I would expect a code the references the knock sensor or the computer would start screwing with the advance to try to stop the detonation problem and either solve the issue or thow more codes.
Another thing to put some though to is the Exhaust manifolds and O2 sensor location. Are they in the stock locations (distance from engine). Are you running aftermarket headers? Aftermarket headers, due to their extra diameter may be giving a false reading on the O2's . The amount of exhaust passing the sensor would be less since the manifold can handle a larger volume. It will delute it a little.

Originally posted by Grim Reaper

nope , it came factory with 2. the only thing i did to the exhaust was to rotate the manifold outlet to clear the frame rails. and the 02 sensors are the same distance as they were in the mustang.