2002 100 Land Cruiser Suddenly Wont "Fire" While Cranking Below 32 Degrees (2 Viewers)

[Recovering Rover]

Some background:
2002 Land Cruiser 100 Series
250K Miles
Check Engine light came on about 500 miles ago; I haven't had any issues so I haven't treated it like an emergency, but I do have a service appointment to get it resolved in early January 2024.

This is the first winter I've owned the vehicle and I haven't had it in below freezing weather yet. I drove it from VA to NY this weekend and the first night the temps got below freezing, I went out the next morning (still 30/31 degrees) and it wouldn't fire - it will turn over fine, but just turns and turns. No other noticeable sounds (puffs/pops/bangs, etc.). I tried it a few more turns and got nothing so I let it rest for 30 min. Went back out (the temp had probably risen a couple of degrees) and it started fine just as if nothing was wrong.

I drove it into town to get some fuel injector treatment and it ran great like it usually does. While there I used the Auto Zone code reader to diagnose the check engine light and got a Code P0420 - "Catalyst System Efficiency Below Threshold Bank 1." I got back to the house and shut it off, then went back out three or four times that afternoon/evening to check it and it cranked fine.

I thought the issue was resolved with the fuel treatment but this morning I had the same issue. Waited until the ambient temperature got to just above freezing and it suddenly cranked, although it took longer today.

Is the temperature just a coincidence? Surely a truck this capable doesn't get finicky just because the temperature gets one or two degrees below freezing?

I appreciate any insight into what may be causing the issue. This is my first Land Cruiser.

 

[open country]

Temperature may be a coincidence, as well as the check engine light which has been happening longer than the no-start issue. Personally I haven't seen a 420 catalytic converter code prevent starting.

If the engine cranking all sounds fine, it just doesn't fire, I'd say fuel is the culprit and electrical given it's sporadic. Check the fuel pump fuse/relay as a starting point and hopefully others can chime in.

 

[Mike NXP]

Taking a random guess here , a lot of folks with a " crank , no start " issue find they have an issue with the EFI relay. I suspect the cold temperatures and check engine light are unrelated.Although, I don't think that issue wouldn't come and go with temperature.



So you can crank all morning in the cold and it will never start?


But then if you try later that day when it's warm, it will start?



Lot of info below. There is a quick check you can do if you have a small jumper cable ( not like the one for starting a car, small wire to run power directly from battery to EFI circuit "
>EFI Relay Bypass Kit (Immobilizer Fix) for UZJ100/LX470 - https://forum.ih8mud.com/threads/efi-relay-bypass-kit-immobilizer-fix-for-uzj100-lx470.952811/

 

[2001LC]

Sound like fuel pump on it's way out. If, security light always goes off as key inserted in IG SW. It is possible, when crank no start condition happens. To test fuel flow. By pinching green securing lock/keep in black plastic fuel line connection, pulling off fuel line from fuel filter. Then see if fuel flows out filter while cranking. Use a hose, catch to can and be supper careful. Gasoline vapor is highly flammable. One spark and your could be killed. Note: Sometimes these failing fuel pumps, are intermittently bad pumps They may flow during flow cranking test, giving a false good pump indication. So may need to repeat a few times.. One clue a false good fuel pump test. It starts as soon as re attach fuel line, after test where fuel did flow out line.

There is a slim chance, prolonged lean fuel condition, affected CAT (PO420). I would only clear PO420 for now. Fix no start issue first. Then take on HWY run. At times shift down and run at ~4,500 RPM, to cook off CATS & O2's. Make sure all spark plug sung (no tick) and oil good, before running at high RPM for 7 to 10 minute intervals, 3 times at minimum.