hocbj23
+1y
A bad TPS can cause the low idle.Backfiring is usually the reult of timing being off(1) or way lean mixture(2).I assume u have checked timing.If the 02 sensor is bad,the bad signal could be causing the backfiring as could a bad TPS.I assume ur mechanic has checked the TPS signal to be sure it is functioning.A lean mixture also could be caused by not enough gas due to a clogged filter or rust in the tank leading to a clogged filter.There is a drain plug on the tank so if u dont have much gas in it,might drain it and see what comes out.If tank is rusty,a good radiator shop can clean it and coat it and there are rubber bladders u can use in them.Hope this helps.BJ