Greetings, everyone:
Went over the 86GT today as it was nice out. Ran and drove great. Smooth and lots of power. Pulled codes. KOEO-11
KOER- 41 and 91. Did the cylinder balance test- all good code 90. No other codes. Checked fuel pressure with KOEO, solid 39 lbs. KOER fuel pressure is about 32 to 34 lbs. Should be a little higher, no? Turned the engine off and checked residual pressure. Pressure slowly rose from 34 lbs to 38 lbs over two minutes. No smell of fuel. Checked secondary air system. Switches to downstream when given throttle. I'll check for vacuum leaks tomorrow.
Last March the entire fuel system except the fuel pump was replaced. New regulator, fuel injectors, fuel lines, and filter. All correct parts. Many vacuum lines are new as is the PCV valve. Here is one repair that shouldn't be related but is.
The fog lights stopped working last summer and I tracked down the culprit to a fusible link that also protects the O2 sensors. Thought that might be the explanation as the lean codes showed up last summer about the same time. Found a correct Ford fusible link and connected it as best I could. Fog lights work great but still running lean. I'll check that repair tomorrow also.
O2 sensors are four years old with less than 40,000 miles on them. Might they really be bad? Shop manual at this point says to check their electrical circuits and grounds.
I suppose a leak in the exhaust system could also cause a lean problem. Will check tomorrow. Any ideas?
Thanks much.
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