2001 Jeep Wrangler 4.0 liter multiple cylinder misfire

Tiny
RONALDHAS
  • MEMBER
  • 2001 JEEP WRANGLER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 86,563 MILES
My jeep I drive it down the road and when it gets up to about 2800 rpms it loses all power and when the rpms go back down it gains power again. I but a code reader on it and it said multiple cylinder misfire. Cylinders 2, 5and 6. Ive changed the plugs the coil pack the fuel pump fuel filter. Im running out of ideas. It acts like its got a rev limiter on it when u put it in park and idle it around 2800 rpms.
Thursday, March 3rd, 2011 AT 11:40 AM

4 Replies

Tiny
CUP1981
  • MEMBER
  • 133 POSTS
It sounds to me like the camshaft position sensor or the crankshaft position sensor is either losing signal or sending inaccurate signal at 2,800 rpm. If the computer senses this, it will shut down fuel flow until it receives a signal again.

Its surprising though that only the random multi misfire code is present. These two parts are the easiest and cheapest to replace at this moment, without a full diagnostic. Let's start there and see what happens.
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Thursday, March 3rd, 2011 AT 11:57 AM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
This is a different expert
The first thing I would be checking here is the fuel pressure during the failure. You would need to rig a fuel pressure gauge in a way that it can be taped to the windshield and observed during the failure to watch what happens when the malfunction starts.
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Thursday, March 3rd, 2011 AT 12:20 PM
Tiny
RONALDHAS
  • MEMBER
  • 2 POSTS
Im in afghanistan right now I got my brother in-law working on it for me. I will have him try the two sensors first. Then I will post what he says happens.
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Friday, March 4th, 2011 AT 4:06 AM
Tiny
CUP1981
  • MEMBER
  • 133 POSTS
Great, keep us updated. Checking the fuel pressure is a good idea as well, just like wrenchtech said. It can give you a feel if it is fuel or spark related.
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Saturday, March 5th, 2011 AT 12:58 AM

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