1998 Jeep Cherokee misses about half way up to normal temp

1998 JEEP CHEROKEE
117,000 MILES • 6 CYL • 4WD • AUTOMATIC
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TGFH
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My Cherokee misses and back fires during warm up. It starts great and runs fine when cold. Then at about 140 degrees to maybe 180 it runs rough. and under power it back fires. Then once it's up to the normal 200 it runs great. I just finished replacing all the front parts (deer) - pass. fender, nose piece and grills, bumper, both radiators, their mounts and had to straighten the inner headlight surround. I replaced the vacuum canister and the line to the cruise control servo. The heater works and so does the cruise. Am I missing some vacuum lines in that front passenger side?
Thanks
Feb 5, 2010 at 8:17 PM
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JACOBANDNICKOLAS
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Does the check engine light come on when this happens? As far as vacuum hoses, it doesn't sound like you missed any. I assume it didn't do this until after hitting the deer. To me, it sounds like a bad temp sensor. Let me know about the light.

Joe
Feb 8, 2010 at 9:52 PM
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TGFH
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no engine lights and the last time I drove it - it didn't happen - frustrating!
Feb 9, 2010 at 9:54 AM
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JACOBANDNICKOLAS
  • CAR REPAIR CONTRIBUTOR
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That is frustrating. My first guess is the temp sensor. If it isn't working correctly, it won't send the correct signal to the computer. As a result, it can cause the engine to run too rich or lean at certain temps.

If it happens again, let me know.

Joe
Feb 9, 2010 at 7:49 PM
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