cardude
New Member
- Joined
- February 26, 2019
- Messages
- 1
- Reaction score
- 0
- City, State
- waldorf, MD
- Year, Model & Trim Level
- 2005, explorer
Hello Forum, seeking diagnosis advice!
Vehicle: 2005 Explorer, 4.0L SOHC non-Flex V6. 155K miles.
Symptoms:
-hard start (sometimes need to depress gas pedal)
-rough idle
-very rough idle when put in gear
Error codes (from a old cheap handheld scanner)
-P0174, which I understand to be “too lean (bank 2)”, and bank 2 = drivers side, where cylinders 4/5/6 are.
1st thing I did: some general maintenance, some of which I have been delinquent on and some of which didn’t think would cause my issue, but was already in there so replaced to rule out. Did the following:
-cleaned throttle body
-replaced spark plugs
-replaced spark plug wires
-replaced ignition coil
-replaced fuel filter
-replaced pvc valve
-replaced mass airflow sensor
-replaced fuel rail pressure sensor
-replaced air filter
-replaced intake manifold gaskets
-replaced left (driver) upper O2 sensor
-replaced right (passenger) upper O2 sensor
**No change in behavior.
2nd thing: built a smoker and checked for vacuum leaks. EGR valve (original) was leaking some.
-replaced replaced EGR valve
**No change in behavior.
3rd thing: Evap purge hose going to top of intake is pretty sketchy looking. Removed from intake and plugged intake port, in case either hose or the purge solenoid is bad.
**No change in behavior.
4th thing: bought a Bluetooth OBDII scanner (amazon, BAFX scanner) and loaded FORScan on a laptop – maybe it doesn’t take much, but I’m really impressed with what one can do with $23 and free software!
-scans show long term and short term fuel trim on Bank 1 to be +/- 5% - and stay that way as a crank RPMs up
-scans show long term and short term fuel trim on Bank 2 to be very high, LTFT2 pegged at 25%, STFT2 near 20%, and increases with higher RPMs
-data looks something like this (importing data into excel and plotting) (attached the jpeg if the insert doesn't work...):
5th thing: with the STFT2 and LTFT2 staying high as a increased RPMs, I concluded that this didn’t look like a vacuum leak, or at least if it was it was a really really bad one, which my smoke test didn’t show. So I thought maybe we’re looking at clogged or dead injectors. Put a mechanic’s stethoscope on the injectors I could get to (easy on bank 1, bank 2 harder) and all seemed to be clicking away. So I cleaned them and swapped them
-removed injectors, noting cylinder position
-cleaned with carb/throttle body cleaner (attaching a tube to the injector, putting cleaner in tube, putting 20 lbs of compressed air on tube, actuating injector by manually pulses the leads with a 12v battery
-all injectors fired
-reinstalled injectors, but put bank1 injectors in bank 2 and vice versa
-new o-ring seals
-before completely installing, test cranked engine with the fuel injectors hanging off the fuel rail. All injectors fired.
-put everything back together
**No change in behavior.
**note, while doing this, went ahead and pulled the valve covers to check out the timing chain. Bank 2 chain is tight, no visible signs of cassette failure. Bank 1 chain had a little slack, no visible signs of cassette failure. new gaskets used when re-installing the covers.
6th thing: scan again. STFT2 and LTFT2 still high. Bank2 is high with what was bank 1’s injectors. So I think I can say the injectors are ok?
So now I’m scratching my head a bit – what to check next….
1-exhaust leak before O2 sensor? take my smoker and put in my exhaust and see what happens
2-injectors? double verify that injectors, fully installed, are injecting? Pull plug wires, crank, and see if plugs are wet?
3-fuel pressure? This explorer don’t have a test port on the fuel rail. Could there be a clog in the pressure rail at/before the bank 2 side? Would weak fuel pump cause this kind of behavior? How best to test fuel pump pressure? Don’t really want to just replace fuel pump.
4-vacuum leak – double verify no vacuum leak? have the laptop plotting LTFT2 and STFT2 and spray propane around intake, brake booster, vacuum lines?
5-timing – double verify bank 2 cassette didn’t explode and timing is whack? Best way to do this? Pull off oil pan and look for chunks of plastic?
6-??????
Soooooo…..thoughts? Comments? Suggestions?
Vehicle: 2005 Explorer, 4.0L SOHC non-Flex V6. 155K miles.
Symptoms:
-hard start (sometimes need to depress gas pedal)
-rough idle
-very rough idle when put in gear
Error codes (from a old cheap handheld scanner)
-P0174, which I understand to be “too lean (bank 2)”, and bank 2 = drivers side, where cylinders 4/5/6 are.
1st thing I did: some general maintenance, some of which I have been delinquent on and some of which didn’t think would cause my issue, but was already in there so replaced to rule out. Did the following:
-cleaned throttle body
-replaced spark plugs
-replaced spark plug wires
-replaced ignition coil
-replaced fuel filter
-replaced pvc valve
-replaced mass airflow sensor
-replaced fuel rail pressure sensor
-replaced air filter
-replaced intake manifold gaskets
-replaced left (driver) upper O2 sensor
-replaced right (passenger) upper O2 sensor
**No change in behavior.
2nd thing: built a smoker and checked for vacuum leaks. EGR valve (original) was leaking some.
-replaced replaced EGR valve
**No change in behavior.
3rd thing: Evap purge hose going to top of intake is pretty sketchy looking. Removed from intake and plugged intake port, in case either hose or the purge solenoid is bad.
**No change in behavior.
4th thing: bought a Bluetooth OBDII scanner (amazon, BAFX scanner) and loaded FORScan on a laptop – maybe it doesn’t take much, but I’m really impressed with what one can do with $23 and free software!
-scans show long term and short term fuel trim on Bank 1 to be +/- 5% - and stay that way as a crank RPMs up
-scans show long term and short term fuel trim on Bank 2 to be very high, LTFT2 pegged at 25%, STFT2 near 20%, and increases with higher RPMs
-data looks something like this (importing data into excel and plotting) (attached the jpeg if the insert doesn't work...):
5th thing: with the STFT2 and LTFT2 staying high as a increased RPMs, I concluded that this didn’t look like a vacuum leak, or at least if it was it was a really really bad one, which my smoke test didn’t show. So I thought maybe we’re looking at clogged or dead injectors. Put a mechanic’s stethoscope on the injectors I could get to (easy on bank 1, bank 2 harder) and all seemed to be clicking away. So I cleaned them and swapped them
-removed injectors, noting cylinder position
-cleaned with carb/throttle body cleaner (attaching a tube to the injector, putting cleaner in tube, putting 20 lbs of compressed air on tube, actuating injector by manually pulses the leads with a 12v battery
-all injectors fired
-reinstalled injectors, but put bank1 injectors in bank 2 and vice versa
-new o-ring seals
-before completely installing, test cranked engine with the fuel injectors hanging off the fuel rail. All injectors fired.
-put everything back together
**No change in behavior.
**note, while doing this, went ahead and pulled the valve covers to check out the timing chain. Bank 2 chain is tight, no visible signs of cassette failure. Bank 1 chain had a little slack, no visible signs of cassette failure. new gaskets used when re-installing the covers.
6th thing: scan again. STFT2 and LTFT2 still high. Bank2 is high with what was bank 1’s injectors. So I think I can say the injectors are ok?
So now I’m scratching my head a bit – what to check next….
1-exhaust leak before O2 sensor? take my smoker and put in my exhaust and see what happens
2-injectors? double verify that injectors, fully installed, are injecting? Pull plug wires, crank, and see if plugs are wet?
3-fuel pressure? This explorer don’t have a test port on the fuel rail. Could there be a clog in the pressure rail at/before the bank 2 side? Would weak fuel pump cause this kind of behavior? How best to test fuel pump pressure? Don’t really want to just replace fuel pump.
4-vacuum leak – double verify no vacuum leak? have the laptop plotting LTFT2 and STFT2 and spray propane around intake, brake booster, vacuum lines?
5-timing – double verify bank 2 cassette didn’t explode and timing is whack? Best way to do this? Pull off oil pan and look for chunks of plastic?
6-??????
Soooooo…..thoughts? Comments? Suggestions?
