i got a 97 f-150 and its been pinging for a few months now and has gradually gotten louder...just the other day it got so loud that you can hear it outside the truck and it threw 2 codes, "lean on bank 1" and "lean on bank 2" iv installed new pcv valve and hose, mass air sensor, new paper air filter, fuel filter, all the gaskets on the intake, egr, and every vaccum hose i can find. just today i bought a fuel pressure gauge, and at idle i have 30psi but i don't know the spec.... truck is still pinging......now what?

 

Can you remember the actual diagnostic code? P####? Ex. P1000?

 

Codes are probably P0171 and P0174. Have you checked the headgaskets? How long ago did you replace the intake gaskets?

 

The very first thing you check out is the MAF when both banks test positive for lean. I just fixed a broken MAF on a 4.0L that had those codes - never seen anything like it . The MAF plastic shell had a 3/16 hole threw it lol and it was dirty as hell. Plugged the hole cleaned the MAF sealed the MAF box up with RTV . Fixed.

ALLData /Ford scorpio - Both banks lean - MAF related. BUT this could and has been PCV leak related in the past on this site and others.

 

the exact codes are p0171 and p0174. i just cleaned the old maf sensor and no change, so i got a brand new one and still no change... i got a brand new pcv valve,hose, and gromet and still nuthin. i did every intake gasket on the truck and replaced all vaccuum hoses on the truck that i could find and i changed the fuel filter and the truck is still pinging! i did all of these things yesterday. i did find out that it doesn't ping or anything when u first start driving it. it seems like it starts immediatly when the computer goes into closed loop

 

RU Rebooting and erasing the KAM after each Air Metering Service?

Are you sure you replaced ALL of the PCV system? The elbow back by the firewall and IAC, where it plugs into the manifold. That elbow is a common problem.

"Pinging" - Try switching gas stations.

 

Are you running a K&N filter by any chance (drop in)

 

Have you checked/tested the air temperature sensor downstream of the MAF sensor?

 

That's right!! Check the IAT gromet as well - that will cause a lean condition if it's leaking.

 

just replaced Iac motor, still no luck....i'll check the IAT out 2morrow. that could cause a lean condition? how do i test it? and also, is 30psi of fuel pressure at the rail enough?

and to answer other questions, i'm running a paper "fram" air filter and yes i have been reseting the computer after i do change sumthin out


thanks for all of yalls help so far

 

Your best bet is to purchase a Haynes or Chilton's service manual to properly test components. Any third party auto supplier will carry one . I think their about $19. That would have been cheaper then an IAC which has nothing to do with lean codes.

 

hey guys, i finaly figured out why i was throwing lean codes in case some of you are having the same problem. since i was tired of guessing and throwing parts on it, i took it up to my auto skool and hooked it up to this badass labscope and it turns out that all my sensors were working properly and the computer was responding like it should.then went back to my house and pulled off the whole intake, sure enough, that thing was clogged up so good with carbon, i could hardly see down it, i manualy cleaned it out put it back on and still had a lean code...i figured that it would probably come back on because i knew the whole combustion chamber and valves would look similar to the intake so i brought it to a lube place and had the fuel system cleaned. after that. it didn't ping near as bad, so the next day i nuked it again with the fuel system treatment, and after that, it doesn't ping at all and the light turned off by itself. so far, i put 2000 miles on it and shes back to normal. took it back to my school and and hooked it back up to the labscope and my short term and long term fuel supply is back to normal. before the fuel treatment, the engine was using 35% more fuel than it should just to keep the engine running and now it doesnt go above 10.9%. i have proved that the fuel system treatment works

 

Which stuff did you use?

 

i don't know exactly what it was, i just took it to the local lube place and they hook a machine up to it and run the vehicle off of the fuel system cleaner that they use. it was just called "cylinder head fuel system treatment"

 

You need to post some pics or something - I have know idea what you cleaned to make lean codes disappear - Something was carboned up? Well, the only thing that gets that way that I know of is the EGR port in the plenum - that wouldn't cause a lean condition. Unless your talking about the MAF ? Your not clear on anything. Kinduh makes this thread useless.

I'll try to help you -

1. You have an Air filter attached to your air intake. The air intake includes the MAF sensor and IAT sensor.
2. The Air Intake connects to the throttle body. The throttle body connects to a curved elbow which is called the plenum.
3. The plenum connects to the upper intake which then connects to the lower intake.

The Plenum is the part that has all the ports in it. Your vacuum lines (EVAP,Brake Booster), IAC and EGR valve connect to that.

This should give you a basic understanding - So , what did you clean ?