First, thanks to everyone on this site for countless solutions to problems I've seen over the years. Despite using it as a resource frequently, this is my first post. I've been working on Toyota 4x4's for over a decade, but at the moment, I'm stumped.
1999 LC 410K miles, Crank, No Start. NO CODES. I've owned it for 6 years, and it's always been reliable, or the problems have been pretty straightforward. Initially, a couple months ago, I started it and it died within about 30 seconds. It hasn't run since. Twice on cranking, it has stumbled a little, but that's all. I'll try to list everything I've tried/tested/replaced:
I have fuel, air, and spark. Compression is acceptable for 410K and doesn't indicate a jumped tooth or other timing belt issue. Belt is current with about 40K on it.
Swapped in new battery/cranked while jumped to another truck, verifying 13+ volts
EFI fuse bypass. Has been running like this for many years with no problems.
New EFI relay
All new parts on TB assembly (Control Motor, TPS, and then replaced the whole thing with a low mile '00 Tundra TB...all the same part numbers as original)
Tried another Fuel Pump
Tested Crank and Cam Position Sensors, both squarely within range
Checked wiring to all sensors and entire engine, finding nothing wrong
Replaced ECU with pre-programmed unit, then swapped back after no change
Checked entire ECU wire harness from Computer to engine, finding nothing wrong (despite a chipmunk nest in my heater blower motor).
Security light goes off when key is inserted and during cranking (tried two keys)
Suspecting bad gasoline, I put a large bottle of stabilizer in the tank, which is full.
Pulled, cleaned and reinstalled spark plugs (which do have fuel on them after cranking)
Cleaned and inspected MAF
Tested all fuses in fuse box (engine bay), and all have voltage on both sides, except if I remove the EFI bypass and replace with a fuse...which we all are familiar with
Clamped fuel return line to make sure pressure wasn't just a little too low
Cranks but won't start in Neutral also, will not crank in any gear but P and N
I have not opened up the timing covers, but decent compression seems to indicate that is ok.
I do not have the full EFI relay bypass...just a jump wire from a hot terminal to the EFI fuse slot. However, this has worked for years, and all systems controlled by that appear to be working.
The only thing that happened since the last time it ran perfectly is that it sat for a couple weeks, and clearly the chipmunks moved in. Thus, I have looked at all wires that I can possibly see without tearing the dash completely apart. The nest was in the blower motor behind the ECU, and still there were no chewed wires anywhere around it or anywhere under the driver side dash.
I'll edit if I forgot something, but basically, I've read thread after thread and tested as much as I can think of. Any thoughts or pointers are much appreciated, thank you in advance.
1999 LC 410K miles, Crank, No Start. NO CODES. I've owned it for 6 years, and it's always been reliable, or the problems have been pretty straightforward. Initially, a couple months ago, I started it and it died within about 30 seconds. It hasn't run since. Twice on cranking, it has stumbled a little, but that's all. I'll try to list everything I've tried/tested/replaced:
I have fuel, air, and spark. Compression is acceptable for 410K and doesn't indicate a jumped tooth or other timing belt issue. Belt is current with about 40K on it.
Swapped in new battery/cranked while jumped to another truck, verifying 13+ volts
EFI fuse bypass. Has been running like this for many years with no problems.
New EFI relay
All new parts on TB assembly (Control Motor, TPS, and then replaced the whole thing with a low mile '00 Tundra TB...all the same part numbers as original)
Tried another Fuel Pump
Tested Crank and Cam Position Sensors, both squarely within range
Checked wiring to all sensors and entire engine, finding nothing wrong
Replaced ECU with pre-programmed unit, then swapped back after no change
Checked entire ECU wire harness from Computer to engine, finding nothing wrong (despite a chipmunk nest in my heater blower motor).
Security light goes off when key is inserted and during cranking (tried two keys)
Suspecting bad gasoline, I put a large bottle of stabilizer in the tank, which is full.
Pulled, cleaned and reinstalled spark plugs (which do have fuel on them after cranking)
Cleaned and inspected MAF
Tested all fuses in fuse box (engine bay), and all have voltage on both sides, except if I remove the EFI bypass and replace with a fuse...which we all are familiar with
Clamped fuel return line to make sure pressure wasn't just a little too low
Cranks but won't start in Neutral also, will not crank in any gear but P and N
I have not opened up the timing covers, but decent compression seems to indicate that is ok.
I do not have the full EFI relay bypass...just a jump wire from a hot terminal to the EFI fuse slot. However, this has worked for years, and all systems controlled by that appear to be working.
The only thing that happened since the last time it ran perfectly is that it sat for a couple weeks, and clearly the chipmunks moved in. Thus, I have looked at all wires that I can possibly see without tearing the dash completely apart. The nest was in the blower motor behind the ECU, and still there were no chewed wires anywhere around it or anywhere under the driver side dash.
I'll edit if I forgot something, but basically, I've read thread after thread and tested as much as I can think of. Any thoughts or pointers are much appreciated, thank you in advance.
