1994 LT-1, 6 speed

Have 115k miles on the car, New plugs, optispark, wires, coil, etc.

The check engine light comes on once every couple of months.

The problem I have, car pings and hesitates when thtottle it tromped down in
higher gears/ low rev/ lugging.

any ideas how to fix it?

 

Wow this board get some traffic.

I could still use some help.

The car pings pretty good when I give it throttle under load.

 

Any mods on the car?

Does the car ping if you downshift into a lower gear and then get on it?

 

Octane booster doesn't raise your octane level as much as it leads you to beleive.

 

only does it under load in higher gears when it's being lugged. It used to never do it.

with knock sensor, type of gas shouldnt matter.

so fars as mods, K&N and big tube, 3 in muffler, air foil. All but the air foil on for years.

 

Have you tried removing the air foil?

 

I never gave that a thought, why would you think it would matter ?

 

Have you ever had it scanned over the many months that it has been setting the SES light? That would be the logical first step.

I would be VERY concerned if you can actually hear "ping".... that means either the knock/detonation is so severe that the knock sensor/PCM/knock retard system can not eliminate it by pulling as much as 15deg of timing, or that the knock retard system is not working at all. Maybe the knock sensor fault is turning on the SES light.

But why guess???.... get it scanned for trouble codes, and also do a data log so you can determine if the knock retard system is working, and if not, what the possible causes might be.

 

I was afraid of that

 

anything else ?

 

prolly bad o2's causing to read rich, with stock timing you shouldn't be pinging, maybe thats something else your hearing?

Matt.

 

Matt, it pings as well as stumbles when you are lugging and tromp the gas. If I down shift I'm OK

 

Hmm... Might be your MAP aswell, if it saying you are at 40kpa & you are at 100 & your getting 45* of timing because of it, that would do it.