My Jeep intermittently bucks while driving and in some cases idles rough. The dilemma
is the check engine light is not triggered for any faults
making it difficult to locate the problem. Sometimes it misses
at idle either warm or cold but not bad enough to stall. However,
driving down the road it looses power completely for 5-10sec sometimes
popping though the throttle body and could be described as "bucking".
A new
crank sensor and fuel pump have been installed. It also
has new plugs cap and wires. All these problems are
very intermittent and it runs perfect otherwise. I have had days go by where it ran perfectly with
no issues. The shop were I had the fuel pump installed could not experience the problem
long enough to figure out.
I was going to try changing out parts .. and wanted to
get some advise here. I was thinking about starting with the
MAP sensor.. but if that where defective the check engine light
would be on right?.. so maybe try the coil and ignition module? I suppose ignition
problems could be undetectable by the ECM?.. help!