87 Chev Celebrity: runs very rich

87 Chev Celebrity
2.5L 4cyl, engine code R, 3 speed Auto, Air

Problem:
-Runs very rich
-poor idle, sometimes stalls at idle
-Off idle stumble, hesitation
-Check engine light ON (originally codes 42, 45, 53)
-Code 42: EST signal did not change when ECM applied bypass voltage
-Code 45: O2 sensor voltage was above spec (rich)
-Code 53: Charging voltage greater than 16.9 for more than 50 seconds.

Attempted Solutions applied
-Replaced MAP sensor, O2 sensor, replaced temp sensor, replaced intake manifold temp sensor
-Replaced spark plugs

Tested battery voltage to be 14.1 volts, charging.

Runs better, but not 100%. Any idea's?

Softheads hi and welcome to the forum, I hope you'll find it usefull

It seems a silly question but how's your fuel-tank?

Jeffie, fuel tank appears to be in good shape and not rusty. Fuel cap appears to be also in good shape.
Is there something else I should be inspecting?

Well you could contemplate on having an engine and/or fuel injection cleaning done. Or perhaps your TPS is broken?

maybe your timing is not advanced enough and you need to adjust.

i have a clue i had 1982 buick skylark bough it for a hundred dollars with this problem. i assume this is 4cyclinder throttle body fuel injection.in gm i found that 4cyclinder,6cyclinder that two things that cause rich condiitions is engine temp sensor oxygen sensor broken vacume lines.i threw away all my code readers i found their miss leading not correct unless you pay ten or twenty thousnd dollars for machine you wasting your time common sense will lead to the problem for an example you already know that cold start run is an enriched mix programed by eeprom chip as motor warms up the sensors start sending signals to main computor.to cut back on enrichment the first sensor scanded is engine temp sensor this is were you check engine light is on this also run temp light or guage also bad antifreeze will confuse temp sensor.depending on whats wrong with sensor is what code you get.as you indicated this is why your confused.the next thing throttle bodys comes loose on their mounts sucking air this causes stalling.also your might want to check over by the battery their a fuse holder check for acid inside holder this will cause stalling this is computor stand by voltage when car is park and turned off.then checkk for good old stand by brooken vaccume hoses.i am willing bet it your engine temp sensor bad and thermostate bad not allowing the engine to warm up to right temp especially the 4cyclinder engine.so i think you have several little problems causing many problems that why so many differ codes code reader garbage will not tell you one from the other unless you calear one problem after the other.good luck

i have a clue i had 1982 buick skylark bough it for a hundred dollars with this problem. i assume this is 4cyclinder throttle body fuel injection.in gm i found that 4cyclinder,6cyclinder that two things that cause rich condiitions is engine temp sensor oxygen sensor broken vacume lines.i threw away all my code readers i found their miss leading not correct unless you pay ten or twenty thousnd dollars for machine you wasting your time common sense will lead to the problem for an example you already know that cold start run is an enriched mix programed by eeprom chip as motor warms up the sensors start sending signals to main computor.to cut back on enrichment the first sensor scanded is engine temp sensor this is were you check engine light is on this also run temp light or guage also bad antifreeze will confuse temp sensor.depending on whats wrong with sensor is what code you get.as you indicated this is why your confused.the next thing throttle bodys comes loose on their mounts sucking air this causes stalling.also your might want to check over by the battery their a fuse holder check for acid inside holder this will cause stalling this is computor stand by voltage when car is park and turned off.then checkk for good old stand by brooken vaccume hoses.i am willing bet it your engine temp sensor bad and thermostate bad not allowing the engine to warm up to right temp especially the 4cyclinder engine.so i think you have several little problems causing many problems that why so many differ codes code reader garbage will not tell you one from the other unless you calear one problem after the other.good luck