Runs to rich REVIEW: (fuel pressure at spec, is always 1st)
I forgot to tell you test# 1.
PIN A23 must be +5vdc (-+0.25v) must or ecu bad or pin a23 is shorted out to ground, or worse. 12v. this is 5v power out to sensors. this dies all sensors die. that use it.
Seen many ECU with this blown up, inside ECU, due to someone hot wiring this pin to 12v or the bad guy hot wiring 5vdc sensors to 12v , not knowing the damage this does....a $400 error.
COMMON complaints: EFI: early 1990s .
in many cases, the ECU flashes, code 12s, all day, and is misfiring and running rich.. (this is like the oldest story of all, and so common, (due to limphome)
this is par for the course on OBD1.
In that, the ECU can not see weak sensors only dead ones (EGR excepted)
keep in mind some countries run NO EGR or have the tests turned off, seen that. outside USA. (no code 51 countries)
In this case, we then start measuring the sensors, running to find the weak cats. (pussy cats)
For example the 02 sensor has near by exhaust leaks. the 02 oxygen sensor pin is now stuck at 0 volts, will cause problems on all EFI cars, but this year car, worse.
MAP hose clogged, or cracked, in almost all cases MAP never fails, (unless smashed by engine swaps) the hoses, well they clog or leak.
ECT reads wrong, 300 ohm hot, is what it must be, not 100 not 500. 300. (or near) 180F = 300 ohms. hot.
IAT must work too, and match same ohms of ECT on and over night dead cold engine, (super easy test, unplug them, ohm it out) see they are equal....(overnight , am checks )
In most cases if the ECu likes the TPS, the TPS is ok, (except at tip in throttle acceleration hesitations that self cure, that is recover if you go 1 potato 2, pot...., )
there are other inputs to the ecu, some are IDLE up, pins, these do not cause rich ever. just 1000 rpm or near)
that is about it.
In 1996 the USA fed. EPA, OBD2, laws, reduced the FAILSAFE (LIMP) mode richness, to a far lower amount and also reduces the 02 sensors, authority.
this means if the 02 lies , the rich trim results, is not so bad , that it burns the CAT TO A CRISP now. like yours will. oldest story #2.
This same rich condition also loves to pack the EGR path solid in pure carbon... un corrected. and smog tests fail. for NOX. oldest story #3
hope this helps. you. and others....
sure wish I knew why your , pins are missing wires. how ODD that....
I forgot to tell you test# 1.
PIN A23 must be +5vdc (-+0.25v) must or ecu bad or pin a23 is shorted out to ground, or worse. 12v. this is 5v power out to sensors. this dies all sensors die. that use it.
Seen many ECU with this blown up, inside ECU, due to someone hot wiring this pin to 12v or the bad guy hot wiring 5vdc sensors to 12v , not knowing the damage this does....a $400 error.
COMMON complaints: EFI: early 1990s .
in many cases, the ECU flashes, code 12s, all day, and is misfiring and running rich.. (this is like the oldest story of all, and so common, (due to limphome)
this is par for the course on OBD1.
In that, the ECU can not see weak sensors only dead ones (EGR excepted)
keep in mind some countries run NO EGR or have the tests turned off, seen that. outside USA. (no code 51 countries)
In this case, we then start measuring the sensors, running to find the weak cats. (pussy cats)
For example the 02 sensor has near by exhaust leaks. the 02 oxygen sensor pin is now stuck at 0 volts, will cause problems on all EFI cars, but this year car, worse.
MAP hose clogged, or cracked, in almost all cases MAP never fails, (unless smashed by engine swaps) the hoses, well they clog or leak.
ECT reads wrong, 300 ohm hot, is what it must be, not 100 not 500. 300. (or near) 180F = 300 ohms. hot.
IAT must work too, and match same ohms of ECT on and over night dead cold engine, (super easy test, unplug them, ohm it out) see they are equal....(overnight , am checks )
In most cases if the ECu likes the TPS, the TPS is ok, (except at tip in throttle acceleration hesitations that self cure, that is recover if you go 1 potato 2, pot...., )
there are other inputs to the ecu, some are IDLE up, pins, these do not cause rich ever. just 1000 rpm or near)
that is about it.
In 1996 the USA fed. EPA, OBD2, laws, reduced the FAILSAFE (LIMP) mode richness, to a far lower amount and also reduces the 02 sensors, authority.
this means if the 02 lies , the rich trim results, is not so bad , that it burns the CAT TO A CRISP now. like yours will. oldest story #2.
This same rich condition also loves to pack the EGR path solid in pure carbon... un corrected. and smog tests fail. for NOX. oldest story #3
hope this helps. you. and others....
sure wish I knew why your , pins are missing wires. how ODD that....
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