1993 Toyota Land Cruiser.
Ever since our first "cold" morning here in Missouri in October 2015, my Land Cruiser does the following on cold startup: cranks just fine without hesitation, revs up like all is well for about 1-second but then the RPMs take a dip to almost a stall before regaining composure and leveling out at around 600-650 RPMS which is the warm idle speed for this engine. A cold engine should not be doing this. For the previous 6 years of ownership on a cold start, it will crank and rev to 1200-1400 RPMS and slowly back itself down to a warm idle speed of 650 RPM over the course of 5-10 minutes if left to idle. This would be the normal sequence. I have no power loss and it runs smooth. I am very well-versed in 80 Series Land Cruisers and have done countless troubleshooting tasks per my Toyota FSM. Close to 100 Cruiser guys (also well-versed) on another forum have chimed in and we still have not figured this issue out. I've replaced several parts with loaner parts from Cruiser friends and nothing has changed. I will leave out everything I have tried at this point as I don't want to rule anything out. One other thing I've noticed is that when I disconnect the battery or pull the EFI fuse to reset the ECU, I get no relearning period whatsoever over the course of the next several drives. It starts up and behaves just like I've posted above. Normal behavior would be a low, rumbly idle as the ECU relearns things. It's almost as if my ECU is stuck in a constant relearn mode. Hard to say!
Thanks!
Ever since our first "cold" morning here in Missouri in October 2015, my Land Cruiser does the following on cold startup: cranks just fine without hesitation, revs up like all is well for about 1-second but then the RPMs take a dip to almost a stall before regaining composure and leveling out at around 600-650 RPMS which is the warm idle speed for this engine. A cold engine should not be doing this. For the previous 6 years of ownership on a cold start, it will crank and rev to 1200-1400 RPMS and slowly back itself down to a warm idle speed of 650 RPM over the course of 5-10 minutes if left to idle. This would be the normal sequence. I have no power loss and it runs smooth. I am very well-versed in 80 Series Land Cruisers and have done countless troubleshooting tasks per my Toyota FSM. Close to 100 Cruiser guys (also well-versed) on another forum have chimed in and we still have not figured this issue out. I've replaced several parts with loaner parts from Cruiser friends and nothing has changed. I will leave out everything I have tried at this point as I don't want to rule anything out. One other thing I've noticed is that when I disconnect the battery or pull the EFI fuse to reset the ECU, I get no relearning period whatsoever over the course of the next several drives. It starts up and behaves just like I've posted above. Normal behavior would be a low, rumbly idle as the ECU relearns things. It's almost as if my ECU is stuck in a constant relearn mode. Hard to say!
Thanks!
Apr 7, 2016 at 7:17 PM
