89 LSI ECU Question

[Rotaryfan23]

Well i have heard that the ECU on the 16v's can go into Limp-Mode. I was curious if the older 8v's such as my 89 will do the same?

[fixkick]

all ECU/PCM and TCM have limphome, even top end, custom ECU have it, (programmable too)
all
but obd1 is more drastic, OBD2 improved that,
the obd1 loves to burn up CATs. !!!
The FSM covers this, poorly
here is my page and even quotes from FSM ,
http://www.fixkick.com/ECU/LimpHome/failsafe.html


change the words "certain level of performance" to , runs like crap, (rpm limt, gross rich, and spark timing retarded)


failsafe.
IT HAS VALUE?
what is it, you can drive with a 100% dead sensor, MAP dead, TPS dead. just about any dead sensor and you can drive it. (not all at once, they FORGOT TO SAY)
the ECU has what is called mimic mode, if say the MAP dies it, creates a very poor virtual MAP sensor.
you drive home slowly and pray no burned up CAT.

with OBD2 the CEL flashes, and that means, drive slow or burn up the cat, but it will burn up way less often than any OBD1 ECU. made.
the operators guide on many a car says.
disconnect the 5000 lb trailer (joking about 5000) and says, drive slow. with CEL flashing (or P0300s)


then there is backup mode.
the whole ecu is toast or ?
and the ECU goes to backup mode, on some cars its a chip that uses RPM to inject, that is it. "the last chance garage." as they used to say.

good luck to you !

[fixkick]

the only hard thing with OBD1 , is not having a working scan tool.
that be it.
and can be had.
see the 32 parameter here, and live data.

http://www.fixkick.com/ECU/Tech1/full_scan2.html

[Rotaryfan23]

the only hard thing with OBD1 , is not having a working scan tool.
that be it.
and can be had.
see the 32 parameter here, and live data.

http://www.fixkick.com/ECU/Tech1/full_scan2.html

Well it just so happens we have a Tech-1 in my shop. Its flashing a code 12 and from what I've gathered it means "No active codes" but it needs to be cleared. Just wish other than the Tech-1 I could tell if it was in limphome. I just rebuilt the motor entire motor and its acting really sluggish and throttle response is terrible. Idles fine and runs smooth later in the rpm range but response is terrible and won't rev hardly over 3800