Engine is "hunting"

JIMCAT · Post by **JIMCAT** » Wed Nov 15, 2006 7:35 am

I have two 86 Tercel SR5 Wagons. The engine on one has just begun seeking or hunting. Surges between 800 and 1200 rpm at idle. Cant find any obvious vacuum leaks. Clogged ERG? Thanks

keith · Post by **keith** » Wed Nov 15, 2006 7:22 pm

Start with the O2 sensor. There is a covered plug under the hood, green, two pins, doesn't go to anything. Put a volt meter between the contacts and if it sweeps, the O2 sensor is good, if not, get a new one.

JIMCAT · Post by **JIMCAT** » Thu Nov 16, 2006 6:43 am

Will check it out. Thank you for the tip.

coltarms · Post by **coltarms** » Thu Nov 16, 2006 9:55 am

Put a volt meter between the contacts and if it sweeps, the O2 sensor is good, if not, get a new one

Sweeps?

JIMCAT · Post by **JIMCAT** » Tue Dec 05, 2006 7:55 am

I followed the instructions in my Chilton's Manual and got no voltage, so I replaced the O2 sensor. No help. The engine is still hunting (seeking). Any suggestions? Thanks

takza · Post by **takza** » Tue Dec 05, 2006 10:55 am

You could try pulling the vac line off of the EGR and plugging it? Might be the vac modulator leaking vac? Check all vac hoses?

JIMCAT · Post by **JIMCAT** » Thu Dec 07, 2006 5:53 am

Will do. No obvious vac leaks but this began right after a valve job, so I am suspecting a leak. Thank you for the advice. jc