QuestionEngine runs rough, minor misfire at idle, misfires badly during accel, engine light on, codes shows multiple cylinder misfires (Haynes Manual) 250,000 miles, newly tuned last year, (distributer, plugs, rotor, cap) new fuel filter, (located under pass. side), small problems then, this worked. Now very consistently runs bad, hot or cold. Speed sensor bad, goes to 40 mhp and fluctuates between 40-50, drops to zero when stopped. Checked air filter, a small mouse had chewed some of the paper, not able to penetrate, mouse droppings, no mouse. Not kidding. Would like to replace cheap/most effective parts first. Changed PCV, small improvement (who chose that location). Thanks.
AnswerBill,
Yes the PCV is in a hard to reach location. No guess on my part as most Japanese engineering is done much better. Vehicle speed sensor is a must since the computer uses it for fuel map and timing. The misfire needs to be looked into. You can use a timing light and see if the miss is consistant by switching to each plug. I would take the distributor a part to check for the presence of oil on the optics. Yes, it was replaced but it is a rebuilt unit. If thye shaft was worn you might be back at oil on the optics. Check the mass airflow sensor with a volt ohm meter. Use the Haynes Manual for the procedure and the values. A bad mass airflow sensor will screw up idle and performance and never throw a code. Beats me since it is on the network but the computer usually reads nothing...
