Good post. Thanks.

 

171 and 174 bank 1 and bank 2 lean, I thought I put that in the first post. My apologies.

 

It was ford mechanics that were unable to fix or solve any problems in the past, so I signed up to this site to learn and work on my own truck to save money and get anything fixed correctly. I only take her in to get tires mounted or exhaust done and even then it's done wrong half the time, just can't find reliable places I guess. I have done research on the procharger and have the kit in the garage and lined up a place to do the tuning or getting a troyer tune.

 

Ok, cool. I am with you. Vacuum leaks are frustrating. Those elbows in the pcv system can hide huge holes on the inside of the elbows. I know you have replaced them, so they should be good. Bend them to see if there are cracks or holes that you may not otherwise see. Is your idle a little faster than normal? Mine would idle around 800, then I found the bad elbow, and it dropped back down to 600/625 or so. Good luck.

 

Does it have trouble starting? Maybe low fuel pressure, not enough fuel getting there, causing it to be lean? Dirty MAF?
http://www.aa1car.com/library/ford_lean_codes.htm

 

My last reply.
He came here with a hard nose and kept being at a distance so no one could really offer any help.
His last reply shows where he is coming from.
Good luck.

 

The first start up in the am it idles upto 1000 and sits for a little bit and then drops down to 600ish, sometimes longer then usual. MAF has been cleaned as well.

 

What you describe for a cold start is normal.
Here is the cold start routine.
Key to run before cranking, the PCM looks at the resistance value of the CHT and the IAT sensors to determine if it is to be a cold start. It has no other way to know this.
The IAC is opened to provide the high idle and extra air.
Fuel injection is richened up.
And ignition timing is advanced.
Ox sensor heaters begin to heat up.
And fuel pump comes on for a second to two to the begin pressure build in the fuel rails.
At cranking the only thing that changes is the fuel pump come on full time..
After the motor starts, the Ox sensors must attain close to 600 degrees to begin outputting their signals.
When this happens they take over fuel injection control from that point on.
The idle speed is set in program.
The idle is attained by looking at the crank sensor output as a Tach signal.
The RPM is compared to the idle table.
If the match is outside +/- 50 rpm a correction is made by modulating the IAC to keep it within limits at all times.
Normal idle is 650 +/- a small amount when fully hot.
.
BTW just got done supercharging a 94 F150 lightening 5.7L with a Vortech centrifugal at 8 psi. Trans has shift kit mods and 4;11 gears.
MSD ignition and boost timing controllers.
Good luck.

 

Thanx! I expect it in the winter but even on hot days occasionally it seems to take much longer then usual to return to normal idle even longer then when its extremely cold, but never has a different affect on the 171 and 174 lean codes. I may just have to deal with the cel until I'm finished rebuilding my new motor, which is getting the procharger. Ive had 3 coils go on this motor in less then a year (2x motorcraft 1x msd), exhaust manifold leak, and the typical head gasket issue on the passenger side and these damn lean codes. Sounds like a few more ponies for ya!