Ok I have an LG4 w/ 700r4 tranny. While in open loop it knocks real easy when I hit the gas and when I am in closed loop it still knocks when I hit the gas but not as bad. could it be a bad knock sensor? The timing is at 6* and I'm out of ideas.

 

yeah could be the knock sensor..

 

Shouldnt the base timing on an LG4 be 0* ATDC?

 

I'm not sure I know that it was set at 0* but it still gave a ping in the same conditions just not as bad so maybe it is but I don't have anything that tells me what it should be so any help would be nice.

 

A vacume test and a compression test can tell you alot! Also, how doyour plugs look? Any oil in the water or visa versa?
could it be bad fuel? just a few thoughts.

 

plugs are only a year old and the car hasn't even been driven for a year. I've tried going to a higher grade of fuel but that didn't help.

 

Ghig,

You can test the EST when setting the base timing. If the timing advances after the bypass is connected (or ALDL jumper is removed) the EST is at least functioning. Check the detonation (or knock) sensor (KS) to see if it is still connected. Inspect the connection to see if it is clean and not corroded. You could remove the sensor and test it as well.

Another thing I've seen is that the KS will get "muted" somewhat by the accumulation of rust and debris in the cooling system. The sensor is installed in what was once intended to be a drain plug hole at the lowest part of the case, and rust, mud, and debris tends to accumulate there. You might want to remove the KS and see if there is a lot of contamination there. If the cooling system has not been flushed and maintained regularly, this is a good possibility. The layer of soft, wet rust and junk can mask some of the signal to the sensor, even though it is screwed directly into the casting.

 

Ok I'll give it a try and get back to you later today.

 

Ok I set the timing to 0* and replaced the knock sensor and that helped alot. it still has a little ping just before the transmission shifts under hard acceleration though.