10-27-2016, 09:19 AM
ok, it may not be in backup mode.
most times the CEL is 100% dead (out ) in backup mode.
backup mode, means, the ECU is blown up, and now in lawnmower mode, a very very very crude, "read TPS angle and now inject off angle" mode. like that.
limphome means a major inputs is bad.
there are other things that can cause rich.
1: high fuel pressure. FPR bad mostly.
2: leaking injector
3: o2 stuck at 0v. (usually caused by cracks in the exhaust near here, the exhaust will suck in air on all cars made with cracks. (at the negative pressure event)
4: ECU bad, in many ways, usually not this. unless the caps are bad and most do go bad caps. a $5 fix.
5: no spark advance. (easy test, in neutral, timing light.?? bingo... dissy dead, fly weights jammed, seen many.
6: CAM BELT SLIPPED, all do that, ever one shortly after 60k miles, is the service point, and the cam goes retarded and huge power loss.
here is the 60A ecu , 89/90 G16a TBI, all are.
http://www.fixkick.com/INJECTORS/89/89-90schem1.jpg
see those 2 pins there,?
a15 , and a9 (DLC ) (aka. monitor port connector on early years, or a DIAG fuse on 1989s.)
a15 blue-yell is diag mode, all one does is ground this one pin, even just key on, not running (or running) and code 12s flash, endless.
this pin must work or you will never know when the ECU sees problems.
here is the 89 diag pin , hidden in the fuse box.
http://www.fixkick.com/CEL/DLC/Fuse-with-diag.jpg
the first, 89s were made in Iwata Japan, then in march , at CAMI, canada.
at the factory move i think the DIAG pins moved too.
key on, with a jumper wire ground the ECU diagnostic pin
most times the CEL is 100% dead (out ) in backup mode.
backup mode, means, the ECU is blown up, and now in lawnmower mode, a very very very crude, "read TPS angle and now inject off angle" mode. like that.
limphome means a major inputs is bad.
there are other things that can cause rich.
1: high fuel pressure. FPR bad mostly.
2: leaking injector
3: o2 stuck at 0v. (usually caused by cracks in the exhaust near here, the exhaust will suck in air on all cars made with cracks. (at the negative pressure event)
4: ECU bad, in many ways, usually not this. unless the caps are bad and most do go bad caps. a $5 fix.
5: no spark advance. (easy test, in neutral, timing light.?? bingo... dissy dead, fly weights jammed, seen many.
6: CAM BELT SLIPPED, all do that, ever one shortly after 60k miles, is the service point, and the cam goes retarded and huge power loss.
here is the 60A ecu , 89/90 G16a TBI, all are.
http://www.fixkick.com/INJECTORS/89/89-90schem1.jpg
see those 2 pins there,?
a15 , and a9 (DLC ) (aka. monitor port connector on early years, or a DIAG fuse on 1989s.)
a15 blue-yell is diag mode, all one does is ground this one pin, even just key on, not running (or running) and code 12s flash, endless.
this pin must work or you will never know when the ECU sees problems.
here is the 89 diag pin , hidden in the fuse box.
http://www.fixkick.com/CEL/DLC/Fuse-with-diag.jpg
the first, 89s were made in Iwata Japan, then in march , at CAMI, canada.
at the factory move i think the DIAG pins moved too.
key on, with a jumper wire ground the ECU diagnostic pin
http://www.fixkick.com