How many knock sensors on a 1991 5.0L engine and can a knock sensor go bad without throwing a code? My engine will continue to ping if I hold the throttle in the same position. I have no codes, the SES light doesn't come on when it pings nor does the ECM seem to retard the timing to compensate for the pinging. I thought that if anything went wrong with the knock sensor, I would get a code. Thanks Guys.

 

only one knock sensor, should be on passenger side above starter. if there is too much initial timing or it goes into a super lean condition, there is only so much the ecu can do to pull timing.

 

Ok, so it's possible that the knock sensor is bad and still not get any codes.

 

Sorry, I forgot to add. Also, what are some common reasons for my car to run lean if that's the case? That would mean it's running lean all the time.

 

Not what he said.
If there is too much knock only so much the computer can do , even if the KS circuit is working correctly

When you you getting the pinging ;WOT , up a hill under load , where.......?

 

Ok, thanks vetteoz, I get it now. The pinging is on load, worse up hill and very annoying. I never actually tried it at WOT. BTW, when mw66nova mentioned the lean condition, I looked into that and found a source that said pinging is a common symptom of the o2 sensor failing so I unplugged it.

http://www.buzzle.com/articles/signs-of-a-bad-oxygen-sensor.html

The pinging was nearly gone and not noticeable in some cases as before. When the car warmed up, naturally the SES light is now on, it still worked much better and there was more pedal response and better acceleration (because of less timing being pulled?).

When it did ping, it would stop. I guess that would be the knock sensor kicking in (?). Had it out today where it was hot out. I noticed the SES light went out and the pinging was a little more noticeable. It seems, once the SES light came back on, the pinging was not as bad and stopping when heard.

What would be my next step, new o2 sensor? I still need to check the fuel pressure correctly and a possible fuel pump where every once and a while, I hear a load noise coming from the fuel tank area even when it’s sitting, not running, in the garage. Sorry for the long posts, I’m just trying to make sure I mention everything for a possible solution and to help others. Thanks guys for your continued support.

 

have you done a fuel filter yet?

 

Yes, I replaced the fuel filter recently.