2001 y250 ox66 - not running on 2 cyl - The Hull Truth

oppitafel · 07-19-2008, 11:08 AM

i have a 250 ox66 - running below 2200rpm the motor's not running on #2 & 5 cyl. above 2200rpm it's running on all 6 cyl.
i have check the output to the coils and there is nothing on those two until you reach 2200 rpms - the others have 195v - above 2200 they all have 195v.
the pulser coils all have 16-18v running at these rpms & charge coils check good too.
i have replaced the o2 sensor (the old one had a 20 ohm reading and the book calls for 100 ohms - kinda funning because the new one has the same reading)
i have test all the other sensor and they check good.
as far as what the service manual says - the cdi (computers) is bad - i have replaced that too and are still having the same problem.
anybody have any ideas.

gw204 · 07-19-2008, 11:13 AM

I've heard that the motor is supposed to drop 2 cylinders at low RPM. Never seen in in print though.

carbo · 07-19-2008, 08:33 PM

Ox66's drop 2 and 5 at idle and pick up one and then the other as rpm's increase.........you can replace everything on the motor and it still wont run on all 6 at idle.

MattH · 07-19-2008, 08:51 PM

Yup, I think it runs on 4 until about 1600 RPMs then not sure if both fire up or they fire up one at a time. They do run rough at low RPMs

DreamWeaver21 · 07-20-2008, 07:24 AM

Quote:

oppitafel - 7/19/2008 10:08 AM

i have a 250 ox66 - running below 2200rpm the motor's not running on #2 & 5 cyl. above 2200rpm it's running on all 6 cyl.
i have check the output to the coils and there is nothing on those two until you reach 2200 rpms - the others have 195v - above 2200 they all have 195v.
the pulser coils all have 16-18v running at these rpms & charge coils check good too.
i have replaced the o2 sensor (the old one had a 20 ohm reading and the book calls for 100 ohms - kinda funning because the new one has the same reading)
i have test all the other sensor and they check good.
as far as what the service manual says - the cdi (computers) is bad - i have replaced that too and are still having the same problem.
anybody have any ideas.

Motor is working fine. That behavior is by design. Good thing you posted here before you went crazy trying to solve this "problem". I am surprised you didn't see this in the manual.