used my obd tester came up with codes dtc12 dtc26 dtc41 and dtc77 koer test any ideas where to start
Mar 23, 2014 at 2:16 AM
1990 Ford Bronco Engine runs rough
BADBOB1368
- MEMBER
- 11 POSTS
12 - Idle control fault
26 - Transmission fluid temperature out of self-test range
41 - Oxygen sensor circuit indicates system always lean
77 - Brief wide open throttle not sensed during test
As you may have noticed, fault codes never say to replace parts, and these aren't even real specific. The first three could be caused by wiring problems. That's more likely than sensor problems. I'd look at the connectors first for those sensors to see if there's corrosion on the terminals or if the terminals are making poor contact.
If you have a spark-related misfire, that is going to send unburned fuel and air into the exhaust system where the oxygen will be detected as a lean condition. How long since the spark plugs and wires were replaced?
26 - Transmission fluid temperature out of self-test range
41 - Oxygen sensor circuit indicates system always lean
77 - Brief wide open throttle not sensed during test
As you may have noticed, fault codes never say to replace parts, and these aren't even real specific. The first three could be caused by wiring problems. That's more likely than sensor problems. I'd look at the connectors first for those sensors to see if there's corrosion on the terminals or if the terminals are making poor contact.
If you have a spark-related misfire, that is going to send unburned fuel and air into the exhaust system where the oxygen will be detected as a lean condition. How long since the spark plugs and wires were replaced?
Mar 23, 2014 at 7:50 AM
not sure picked this rig up cheap plugs look sparkly clean like new but im not sure ill pull them and take a peak thank you ill get back to you on that.
Mar 23, 2014 at 1:12 PM
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