91' explorer runs too lean..please help
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91' explorer runs too lean..please help
hello there and thank you all for past help,
I have a 91' explorer 4.0L 4x4 autotrans 165,000miles good compression and runs good. However, the check engine light started coming on intermittily so I coded it out and got 57 85 41. From what i gathered it is 57 octane adjust service pin installed 85 electronic control assembly status "lean" limit reached in fuel control program 41 exhaust gas oxygen voltage signal always lean.
any ideas???? maybe a vac leak or oxygen sensor???? Is there a way to clean a Oxygen sensor???
What about fuel pressure???? I'll check that now.
thanks again this web site rocks.....Justin
I have a 91' explorer 4.0L 4x4 autotrans 165,000miles good compression and runs good. However, the check engine light started coming on intermittily so I coded it out and got 57 85 41. From what i gathered it is 57 octane adjust service pin installed 85 electronic control assembly status "lean" limit reached in fuel control program 41 exhaust gas oxygen voltage signal always lean.
any ideas???? maybe a vac leak or oxygen sensor???? Is there a way to clean a Oxygen sensor???
What about fuel pressure???? I'll check that now.
thanks again this web site rocks.....Justin
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ok, you guys are going to think I'm a real wako but check this out.
I just tested the fuel pressure and it is @ 40psi runs just great and then a minute or two later it spikes the neddle @ 90psi and starts butterflying between 85-95 and the truck starts idealing very rough. oh yea, I can hear the fuel pump charge up when it spikes the pressure.
I just tested the fuel pressure and it is @ 40psi runs just great and then a minute or two later it spikes the neddle @ 90psi and starts butterflying between 85-95 and the truck starts idealing very rough. oh yea, I can hear the fuel pump charge up when it spikes the pressure.
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Joined: Aug 2001
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From: South Texas
Fuel pressure regulator is bad. Should read 30-35 PSI at idle with vacuum hose on it and 40-45 PSI without.
Fix the pressure problem till stable, clear the PCM and drive it to see if lean/O2 sensor codes return. Lean codes are most likely related to the fuel pressure stability problems. Octane shorting code will come up if the shorting plug has been removed from its socket, but I do not think this code will turn on the MIL light.
Dialtone
Fix the pressure problem till stable, clear the PCM and drive it to see if lean/O2 sensor codes return. Lean codes are most likely related to the fuel pressure stability problems. Octane shorting code will come up if the shorting plug has been removed from its socket, but I do not think this code will turn on the MIL light.
Dialtone
Last edited by Dialtone; May 10, 2006 at 10:35 PM.
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Joined: May 2002
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From: Phoenix
Originally Posted by Dialtone
Fuel pressure regulator is bad. Should read 30-35 PSI at idle with vacuum hose on it and 40-45 PSI without.
Fix the pressure problem till stable, clear the PCM and drive it to see if lean/O2 sensor codes return. Lean codes are most likely related to the fuel pressure stability problems. Octane shorting code will come up if the shorting plug has been removed from its socket, but I do not think this code will turn on the MIL light.
Dialtone
Fix the pressure problem till stable, clear the PCM and drive it to see if lean/O2 sensor codes return. Lean codes are most likely related to the fuel pressure stability problems. Octane shorting code will come up if the shorting plug has been removed from its socket, but I do not think this code will turn on the MIL light.
Dialtone
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