white80zred89rs

I would just like to know some of the symptoms of a bad knock sensor. My 89 305 TBI is pinging when it's warm, and it doesn't seem to change when I put different fuel in. It idles strange too; when it's warm and you've been romping on it, it can't keep a steady idle speed. This changes though a little depending on the gas you put in. It has even died on me a couple of times at a stop light, but always starts back up again. Performance hasn't changed noticeably, and I'm still getting around 20 mpg average. No trouble codes either. It's not the EGR valve or anything that has to do with the TB.
Any ideas?

paulo57509

There was a time where you could watch the timing marks with a timing light, lightly rap on the exhaust manifold with a hammer and if the knock sensor was working, you can watch the timing marks retard.

white80zred89rs

Where is the knock sensor located anyway? I heard that there may be more than one also; is that the case on an 89 305 TBI?

trans_am_ta_84

it's on the passenger side of the block and i beleive it's under the manifold.

Air_Adam

Passenger side coolant drain hole... its right near the starter.

3rd gen V8

what happens if your knocksenser is not hooked up? becuase my car runs fine but i think it's a little weak than it should be.
and oh it might be the 170000 miles on the car lol

Air_Adam

If its not hooked up, IIRC, it will go into a preset "limp home" mode, which seriously kills everything... no power, poor running, and bad mileage.

trans_am_ta_84

well like air adam said it won't be alittle weak it will be like running on 5 cylinders. it retards the timing and then the car won't even want to move.

3rd gen V8

well my car drives just fine thoe but the sensor is unpluged and i cant find the wire that went to it either.

92rs85berlintta

iTrader: (1)

pull it out put a volt meter on it and tap it with a piece of metal and see if the reading jump between .5-1.5 volt or somere around that. put the black volt meter prong on the threads and the red on the connector.