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89 cherokee 4.0 runs rough

N

nynatv

NAXJA Forum User
Location
Vermont
I am trying to troubleshoot an 89 cherokee 4.0 that idles fine and runs very rough when throttle is applied. New cap, rotor, coil.
It starts right up, idles good. I'm thinking it's a spark issue. I connected the bulb between the coil and dist cap and when idling I get a solid light but when throttle is applied the bulb blinks as if not a continuous spark. Any suggestions? Am I looking in the right direction?
 
Most likely a fuel flow rate problem, or a loose vacuum line between the throttle body and the MAP sensor. May be a bad coil or primary wire.

OH, the TPS could be bad too. ECU needs good data from the MAP and TPS during throttle application.
 
Brand new coil. I put the bulb between the coil and the center port on the dist cap. I ohm'd out the wires and they all had approximately +/- 6.0 ohms of resistance. Is that normal? I also put a fuel gauge on it and the gauge read dead on according to specs...
 
nynatv said:
Brand new coil. I put the bulb between the coil and the center port on the dist cap. I ohm'd out the wires and they all had approximately +/- 6.0 ohms of resistance. Is that normal? I also put a fuel gauge on it and the gauge read dead on according to specs...
Click to expand...

What wires? Regular HV wires should be about 1000 ohms per foot IIRC.
 
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