P0171 code

[Razor]

Hey guys,
I have been working on the truck chasing this code for 2 weeks without any luck. The truck has not been driven much in the last year, but has its 2nd fresh tank of 93 Shell in it. I am unable to find a vac leak. I have reset the computer twice with the same results. Only thing I have changed is the old fuel filter. I have been talked out of changing the passenger side upstream 02 sensor. I have not tried to pull the 90 EGR boot at 12oclock behind the supercharger - heck I cannot even see it! The truck idles smooth at -18 on the autometer until I turn on the fan blower which raises it to -15 with a little surge. Not sure if this is normal. Any suggestions gladly appreciated.

Chris

[L8 APEX]

Clean the MAF with MAF cleaner check and or restrict the passenger PCV checks.

[Razor]

I have been running a breather on the passenger side valve cover for years, any effect?
What are the odds of getting the 90 boot off without pulling the supercharger?

[L8 APEX]

With a cold engine and numble hand you can get it. I usually zip tie a 3/8 vacuum cap onto it. I think a dime covers that inlet hole on the upper intake behind the IAC motor. You can try that for a few days and see if the code goes away. If you have a single blade TB you can try closing it a little. lean codes are usually from unmetered air which is usually from the PCV system.

[Razor]

I will attempt to yank it off. From this pick - it looks like fun! I am hoping the elbow is bad! So I can drive with it blocked off?3934

[L8 APEX]

Yes, the purpose of PCV is to pull a negative on the valve covers and crank case. This promotes ring sealing, compression and makes some HP. With a breather you are open to the atmosphere anyway. So what is the tube sucking from, just the lower intake.

[Razor]

Yes, the purpose of PCV is to pull a negative on the valve covers and crank case. This promotes ring sealing, compression and makes some HP. With a breather you are open to the atmosphere anyway. So what is the tube sucking from, just the lower intake.

Since the truck has always had the breather, why would the 90 boot leaking cause a problem? I plan on reaching for it tonight!
BTW: Are you back in Texas?

Thanks,
Chris

[L8 APEX]

If the elbow fails then the intake sucks in a ton of unmetered air essentially simulating a hole in the intake. Boost bleeds out and outside air sucks in but they usually rot shut. I guess the air trough the PCV port is an engineered acceptable amount.

[Razor]

If the elbow fails then the intake sucks in a ton of unmetered air essentially simulating a hole in the intake. Boost bleeds out and outside air sucks in but they usually rot shut. I guess the air trough the PCV port is an engineered acceptable amount.

I was unable to get the boot off. I replaced the breather with the stock oil cap. I notice a massive humming noise from the passenger cylinder head by using a hose to my ear. All the injectors are ticking there life away. I hooked up a fuel gauge as well. It idles at 32psi. When I rev it it bumps up 2-3psi and goes back to 32 holding the idle up. Not sure if this is normal. I have a friend with a longer - skinnier arm that may be able to yank that 90 off while my wounds heal.

Oh! I have gone 8 miles on a fuel tank and just watched the fuel gauge drop to 3/4..and it stays there.

[L8 APEX]

The injectors are noisy, Ford has gone to a different injector now and they also cover them in foam to quiet them. 30-35 at idle and cruise and 50-55 at WOT under load is normal. If the gauge stops working it is normally the sender in the tank. If you go in there I would do pumps, stainless Y connector and fuel lines at the same time.

[Beaudee]

Not sure if your problem,but my EGR valve stuck open and the solenoid swicth that controls it went bad(truck barely ran) giving same code.Replaced it all truck went a few months O.K. and i just got the same code again.Im gettin rid of the EGR completely with a LFP delete kit.I was able to check that boot on the back of intake barely but seemed good.I need Keven Durant Oklahoma b-ball player to change it LOL.So far found loose pvc valve in boot http://www.ebay.com/itm/GENUINE-BRAND-NEW-Motorcraft-EV-238-PCV-Valve-F75Z-6A666-BA-/170922860240?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AFord%7CSubmodel%3ALightning&hash=item27cbcbded0&vxp=mtr comes with boot and valve 7 bucks.If Terry chimes in ,any advice with the EGR delete kit i just ordered it?

[jmlay]

I had similar problems this fall. I am not sure if it was a coincidence of not but this seemed to appear after I cleaned the throttle body. the solvent from TB cleaner was the last straw for the lower intake 90deg boot at the bottom of the intake.

My recommendation would be to remove the breather, cap off the lower intake, check ALL of the vacuum lines & run a PCV line from the passenger valve cover to upper intake. Last but not least follow the steps in the link below to check the EGR system.

http://easyautodiagnostics.com/ford_egr_test/ford_egr_valve_1.php

Thanks,
Mike