My 1992 4Runner just started idling rough, especially at cold start. Plugs, cap and rotor were replaced about 3,000 miles ago; valves were adjusted at the same time. The engine has 265,000 miles on it, but runs well above 2,000 RPM. Where should I start with troubleshooting? Any suggestions will be much appreciated.

 

It could be a number of things...

look for vaccum leaks

short diag port and look for codes (http://www.4crawler.com/4x4/CheapTri...es/index.shtml)

Throttle Positioning Sensor, TPS, In need of adjustment (http://www.4crawler.com/4x4/CheapTri...#TPSAdjustment)

Consult Factory Service Manual (http://personal.utulsa.edu/~nathan-buchanan/93fsm/)

Good luck. Hopefully other more experienced members will chime in.

 

Check your fuel filter, and I would do the Seafoam treatment. Clean out the mess caused by the EGR. Make sure all vacuum lines are clear and flowing, especially off of the Plenum.

 

Thanks for the input, folks. I will take these suggestions up this weekend.