Idle speed not raising on heat or headlights

[fixkick]

hot normal temps, and engine idle controls failed causes all. told in Physics way or , Otto Cycle ways.

1: ECU in limp-home mode (DTC errors set)
2: engine is weak (cam belt slipped tops list) or low engine compression. and lots more... lots of tests, to find bad engine ,
3: engine misfiring grossly. (lots of causes, but spark and fueling bad it is) even suck open EGR valve.(even bigger list of tests)
4: ISC valve jammed up (gunked up) seem to me it is not.
5: the engine can't breath nor pump air, really this is #2, in my book.

or even more simple.
1:bad engine,
2: ECU brain not happy. DTC #112 is happy, all others, not.


the whole purpose of limp home mode is.
NO DEAD ENGINE<! not being stranded can save a life. (ponder that)
you can drive to the repair shop and the man fixes. it. true then true now. 99% do. now.

[TracyDJMan]

Cel is working correctly.

[fixkick]

Cel is working correctly.

does that mean code 12 flashes out?

[fixkick]

btw code 12 does not mean all is hunky dory , bless, it only means sensors not dead.
sensors can be weak are not reported, and just as bad running.
the ECU can get lost too. (means for example O2 sensor lies and can not control) the 02 sensor test are not very good. back then.

the RPM drop can be caused by many things.
Driving with DLC jumpered and code 12 flashing all the time (harmless it is) and then changes to other codes is finding intermittent problems.
when 600rpm happens do you hear the misfire?

ok, a good O2 sensor test, is unplug it, if the 600RPM ends, the 02 is bad.
this car loves to do that, bad 02 and goes rich and engine runs bad rich, even spark plug tips turn black with carbon rich.
removing the 02 plug, causes a trick that causes 02 missing input to go to 0.45vdc this voltage tells ECU fuel mix ok and causes leaner fuel and runs better is possible,.
one more trick 8v.
is remove huge air horn, idle engine now, and have person #1 cut the key as you look down the throttle body air horn, the single injector must stop spraying fuel if not the injector leaks.
a leaking injector can be it or the two 29 year old O-RIngs are cracked on it. super old those are and may be like all full of cracks those rings.
cheers and good luck.

[TracyDJMan]

btw code 12 does not mean all is hunky dory , bless, it only means sensors not dead.
sensors can be  weak are not reported, and just as bad running.
the ECU can get lost too. (means for example O2 sensor lies and can not control) the 02 sensor test are not very good. back then.

the RPM drop can be caused by many things.
Driving with DLC jumpered and code 12 flashing all the time (harmless it is) and then changes to other codes is finding intermittent problems.
when 600rpm happens do you hear the misfire?

ok, a good O2 sensor test, is unplug it, if  the 600RPM ends,  the 02 is bad.
this car  loves to do that, bad 02 and goes rich and engine runs bad rich, even spark plug tips turn black with carbon rich.
removing the  02 plug, causes a trick that causes 02 missing input to go to 0.45vdc this voltage tells ECU fuel mix ok and causes leaner fuel and runs better is possible,.
one more trick 8v.
is remove huge air horn,  idle engine now,  and have person #1 cut the key as you look down the throttle body air horn, the single injector must stop spraying fuel if not the injector leaks.
a leaking injector can be it or the two 29 year old O-RIngs are cracked on it.  super old those are and may be like all full of cracks those rings.
cheers and good luck.

Brand new O2 sensor.

[TracyDJMan]

Cel comes on with key and immediately goes off with ignition. O2 sensor unplugged made no difference. I looked at ecu, capacitors look normal. Replaced PCv valve. I’m leaning towards it being an issue with the map sensor at this point. Can it be cleaned?

[TracyDJMan]

Also, I failed to mention that even when the rpms are low it still seems to run normal. No misfiring or anything weird. I just tried running without map sensor and rpms went super low and it sounded like shit.