1999 Disco II, 147K miles
OK, Wife's daily driver. Drives about 80 miles round trip daily.
Today she is driving home and says at about 50mph it stumbles a little
and then starts to run rough at all speeds while driving.
She makes it home and I put the tester on it.
Reading P0301 and P0300.
Cleared the codes. Pulled plug #1 and checked spark. Got good spark.
Checked oil and it looks good (needs to be changed, but normal looking)
Coolant is about 2 cups low, so I top it off.
Checked gas cap, all good there.
Took it for a drive, still stumbling and stuttering, and throwing same codes.
I'm at a loss as to what to check next.
History is that I've replaced the coil packs, wires and plugs 4 months or so
ago. New MAF about 18 months ago. Replaced CKps about 2 years ago.
Gonna throw the live data numbers from my code reader out there to see if anyone
can make heads or tails of it.
At idle here is what it shows
Fuel Sys 1 CL
Fuel Sys 2 CL
Engine Coolant Temp 208
STFT B1 (%) -5.4 to +3.1 Variable
LTFT B1 3.1 Constant
STFT B2 (%) -2.9 to +6.2 Variable
LTFT B1 1.5 Constant
Engine RPM 750 to 830 (kinda lopey)
Spark Advance (degrees) 9 to 13 variable
Intake Air Temp 100
MAF (LB/Min) 0.734 to 0.960 Variable
O2 Sensor B1 S1 (V) 0.075 to 0.830 Variable
STFT B1 S1 (%) -4.6 to +7.0 Variable
O2 Sensor B1 S2 (V) 0.825 to 0.840 Variable
STFT B1 S2 (%) N/A
O2 Sensor B2 S1 (V) 0.145 to 0.780 Variable
STFT B2 S1 (%) -4.6 to +6.2 Variable
O2 Sensor B2 S2 (V) 0.055 to 0.155 Variable
STFT B2 S2 (%) N/A
So then I rev it up and hold it at 2000 RPM, no stutter, no stumble, no codes.
Here is the live data from that:
Fuel Sys 1 CL
Fuel Sys 2 CL
Engine Coolant Temp 194
STFT B1 (%) -2.3 to +0.0 Variable
LTFT B1 3.1 Constant
STFT B2 (%) -0.7 to +5.4 Variable
LTFT B1 1.5 Constant
Engine RPM 2000 constant (+/- 10 RPM)
Spark Advance (degrees) 33
Intake Air Temp 122
MAF (LB/Min) 1.56 to 1.64 Variable
O2 Sensor B1 S1 (V) 0.145 to 0.775 Variable
STFT B1 S1 (%) -3.9 to +6.2 Variable
O2 Sensor B1 S2 (V) 0.185 to 0.360 Variable
STFT B1 S2 (%) N/A
O2 Sensor B2 S1 (V) 0.105 to 0.785 Variable
STFT B2 S1 (%) -1.5 to +8.5 Variable
O2 Sensor B2 S2 (V) 0.055 to 0.115 Variable
STFT B2 S2 (%) N/A
Then pulled it out of the driveway and took it for a spin, and immediately it
threw the P0301 and P0300 codes again.
Any of you Guru's make anything of this data that might save us a trip
to an indy shop to have them try to figure this out? I'm pretty good at
working on this thing and we have done all our own work to it so far, but
this one has me stumped. And I don't have a compression tester or I would
have checked that and provided the data too, but since my fluids seem good,
I'm thinking I don't have a problem there.
It does leak live a seive on oil from the valve cover gaskets, but the head
gaskets actually don't look like they are leaking anywhere. Lots of oil on
the bottom of the engine, likely from timing cover or something up front,
but it only uses about 1/2 quart every two weeks.
So there it is. Open to any and all shade tree mechanics (or professionals) to
comment. Let me know what you think!
Thanks in advance,
Smittygj
OK, Wife's daily driver. Drives about 80 miles round trip daily.
Today she is driving home and says at about 50mph it stumbles a little
and then starts to run rough at all speeds while driving.
She makes it home and I put the tester on it.
Reading P0301 and P0300.
Cleared the codes. Pulled plug #1 and checked spark. Got good spark.
Checked oil and it looks good (needs to be changed, but normal looking)
Coolant is about 2 cups low, so I top it off.
Checked gas cap, all good there.
Took it for a drive, still stumbling and stuttering, and throwing same codes.
I'm at a loss as to what to check next.
History is that I've replaced the coil packs, wires and plugs 4 months or so
ago. New MAF about 18 months ago. Replaced CKps about 2 years ago.
Gonna throw the live data numbers from my code reader out there to see if anyone
can make heads or tails of it.
At idle here is what it shows
Fuel Sys 1 CL
Fuel Sys 2 CL
Engine Coolant Temp 208
STFT B1 (%) -5.4 to +3.1 Variable
LTFT B1 3.1 Constant
STFT B2 (%) -2.9 to +6.2 Variable
LTFT B1 1.5 Constant
Engine RPM 750 to 830 (kinda lopey)
Spark Advance (degrees) 9 to 13 variable
Intake Air Temp 100
MAF (LB/Min) 0.734 to 0.960 Variable
O2 Sensor B1 S1 (V) 0.075 to 0.830 Variable
STFT B1 S1 (%) -4.6 to +7.0 Variable
O2 Sensor B1 S2 (V) 0.825 to 0.840 Variable
STFT B1 S2 (%) N/A
O2 Sensor B2 S1 (V) 0.145 to 0.780 Variable
STFT B2 S1 (%) -4.6 to +6.2 Variable
O2 Sensor B2 S2 (V) 0.055 to 0.155 Variable
STFT B2 S2 (%) N/A
So then I rev it up and hold it at 2000 RPM, no stutter, no stumble, no codes.
Here is the live data from that:
Fuel Sys 1 CL
Fuel Sys 2 CL
Engine Coolant Temp 194
STFT B1 (%) -2.3 to +0.0 Variable
LTFT B1 3.1 Constant
STFT B2 (%) -0.7 to +5.4 Variable
LTFT B1 1.5 Constant
Engine RPM 2000 constant (+/- 10 RPM)
Spark Advance (degrees) 33
Intake Air Temp 122
MAF (LB/Min) 1.56 to 1.64 Variable
O2 Sensor B1 S1 (V) 0.145 to 0.775 Variable
STFT B1 S1 (%) -3.9 to +6.2 Variable
O2 Sensor B1 S2 (V) 0.185 to 0.360 Variable
STFT B1 S2 (%) N/A
O2 Sensor B2 S1 (V) 0.105 to 0.785 Variable
STFT B2 S1 (%) -1.5 to +8.5 Variable
O2 Sensor B2 S2 (V) 0.055 to 0.115 Variable
STFT B2 S2 (%) N/A
Then pulled it out of the driveway and took it for a spin, and immediately it
threw the P0301 and P0300 codes again.
Any of you Guru's make anything of this data that might save us a trip
to an indy shop to have them try to figure this out? I'm pretty good at
working on this thing and we have done all our own work to it so far, but
this one has me stumped. And I don't have a compression tester or I would
have checked that and provided the data too, but since my fluids seem good,
I'm thinking I don't have a problem there.
It does leak live a seive on oil from the valve cover gaskets, but the head
gaskets actually don't look like they are leaking anywhere. Lots of oil on
the bottom of the engine, likely from timing cover or something up front,
but it only uses about 1/2 quart every two weeks.
So there it is. Open to any and all shade tree mechanics (or professionals) to
comment. Let me know what you think!
Thanks in advance,
Smittygj