Davek
New Member
- Messages
- 5
- Location
- Parsonsburg
LEXUS SC400 misfires on 2,4,6 & 8. Seems like I checked everything. Well here are the facts. 1997 Sc400 v8 4.0 1uz-fe engine,
automatic trans. Timing belt failure, bent two valves on left hand bank. Went ahead and pulled the heads and had a valve job
done.The bottom end was really clean (no ridge at top of cyl). Cleaned everything up. put it all back together (by the
book).After it was totally reassembled, the engine started right up first try(cool, all appears good), no smoke, no funny
noises. Feeling pretty good at this time. Well the engine is idling poorly. I plugged in the hand held scanner, all values
are within range of charts in the lexus book, but the scanner shows misfires on just the right hand bank. OK the engine runs
poorly at lower rpms. if you take it for a drive, when you get to 2800 rpms the engine clears right up and will put you back
in your seat. Runs great at higher rpms. Seems to run better before it get to 154 degrees. Here's some things I've check to
be sure (or did because other people said it would take care of the problem). Check vsv's and vacuum hose routing, vacuum
tested appropriate devices and hoses. Good fuel pressure and fuel flow. Replaced fuel filter. Pulled fuel pump out and
tested/visually inspected. Triple checked timing belt alignment. Then had a diesel mechanic tell me to switch injectors over-
left bank to right bank..visa versa--. Also checked plugs and ignition wires.STILL MISSES ON 2,4,6,8..It starts missing on
one of the even cyls, usually #8 and then the other slowly start missing in no particular order. It doesn't matter if I clear
the memory or not. Engine normally stays at 189 degrees. One other thing to mention the temp gauge goes straight up (hot
plus) after a few minutes of running. The scanner show 189 degrees.
automatic trans. Timing belt failure, bent two valves on left hand bank. Went ahead and pulled the heads and had a valve job
done.The bottom end was really clean (no ridge at top of cyl). Cleaned everything up. put it all back together (by the
book).After it was totally reassembled, the engine started right up first try(cool, all appears good), no smoke, no funny
noises. Feeling pretty good at this time. Well the engine is idling poorly. I plugged in the hand held scanner, all values
are within range of charts in the lexus book, but the scanner shows misfires on just the right hand bank. OK the engine runs
poorly at lower rpms. if you take it for a drive, when you get to 2800 rpms the engine clears right up and will put you back
in your seat. Runs great at higher rpms. Seems to run better before it get to 154 degrees. Here's some things I've check to
be sure (or did because other people said it would take care of the problem). Check vsv's and vacuum hose routing, vacuum
tested appropriate devices and hoses. Good fuel pressure and fuel flow. Replaced fuel filter. Pulled fuel pump out and
tested/visually inspected. Triple checked timing belt alignment. Then had a diesel mechanic tell me to switch injectors over-
left bank to right bank..visa versa--. Also checked plugs and ignition wires.STILL MISSES ON 2,4,6,8..It starts missing on
one of the even cyls, usually #8 and then the other slowly start missing in no particular order. It doesn't matter if I clear
the memory or not. Engine normally stays at 189 degrees. One other thing to mention the temp gauge goes straight up (hot
plus) after a few minutes of running. The scanner show 189 degrees.
