Running Rough

[90runner]

1990 cherokee laredo. 4.0

runs rough between 800-1800 and backfires. Over 1800 runs perfect. Could this be the throttle position sensor, or what? HELP ME OUT GUYS thanks.

 

[AberdeenLiberty]

Check, plugs, wire, air filter, and pcv valve 1st.

 

[briejer]

Just start tossing money on everything it might be, or use a scan tool to make a better guess

 

[64FJ40]

If it idles at 800 or so, the tranny shifts correctly, and the throttle response seems linear above 1800, it's *probably* not the TPS.