Background: 1992 Firebird Formula
305 TBI, little over 150k on Engine
Bone Stock, only aftermarket part is K&N air filter.

Decided today to check my timing. Brought out the timing light, unplugged the ECT connector, and went to town. Timing mark was reading right at 0 Deg...apparently stock setting.

Mileage hasn't been the greatest in city, so figured would advance it a bit to see if an improvement was possible. Advanced the timing mark to 6 Deg. Reconnected the sensor, took her for a spin. Pinging was pretty bad.

Repeated the same procedure but backed it off a bit to 4 deg adv. Still pinging noticeable.

Ok, so that was a no go, so I set it back to the factory 0 deg. Car is still pinging!? Under moderate acceleration. It never pinged before! I don't get it. Everything is connected as it should be, timing is at 0 deg, but the pinging hasn't disappeared.

Prior to today and the timing check, engine never pinged.

Any ideas? Does the computer have to make adjustments for a while after resetting the timing to go back to 'normal'? Or am I crazy?

Thanks

 

this may sound just as simple or crazy. i have unplugged the connector then started engine, set timing, shut off, plugged in and restarted. try it. if not go a couple degrees retarded and try it. by the way did you just fill up. is the fuel older. try and fill it with some fresh 91 octane/

 

I'd check the egr too, it helps w/ pinging, when the engine is idling, press under the valve w/ your finger, it should run rough or die. That tells you the valve & passage is clear.
Then you'll have to hook a vacuum gauge up to the egr hose & rev the engine, you should get vacuum only revved up. On some cars you have to be driving for the egr to work, but I don't think that applies to your car.

 

EGR is off during idle, right?

If initial SA is correct, I would check fuel pressure.

 

right it doesnt do anything when engine is idling. but you read that wrong thomas. he said check egr, it helps with pinging. and then went into how to check it at idle. That is usually the first test you do when testing egr.

it is odd that your car is now pinging anywhere. are you sure you disconnected the right connector to adjust timing?

did you accidently break one of the plastic egr lines while messing with the car?

are you sure you did nothing else?

 

Yes I did, sorry.

As usual ex-x-fire was wery helpful, with his good knowledge.

 

Did you tighter the dist down? Possibility it slipped?