I have a 89 Iroc, 350. Motor has about 5k miles on it. Lately the car has been pinging pretty bad when it passes 3500 rpms. And only when it is at operating temp and when under load. I have had a few relatives tell me that it is a bad egr or bad injectors. To me, I think I need to re-adjust my valve lash.

Do you guys have any opinions/comments?

I have been experiencing bad gas mileage and a strong gas odor every now and then when starting or coming to a stop after driving on the freeway for a while. I know I have a bad sensor on the egr, and have been meaning to fix it, so I believe that is my problem with gas mileage. But I am not sure on the gas odor. Those are the only other symptoms the car has been experiencing, if they are all related somehow, I am not sure.

I sure could use some of your invaluable feedback.

Thanks
Steve

 

None of the things you mention really have anything to do with the problem.

Pinging is almost always caused by the timing being too advanced. I'd start there. Setting it by the mark may or may not be the right thing to do; th emark may not be accurate (they usually aren't), the engine may be different in critical ways (compression) such that the factory timing curve programmed into the ECM is no longer optimum; or your knock sensor is bad and not hearing it.

A great place to start on a bad gas mieage complaitn is the O2 sensor.

 

But the ECM thinks that the EGR is working, and advances the timing to take advantage of the lower combustion temps. If the valve is stuck shut or not getting any vacuum to open it, that may be why it's pinging.

I'd fix the EGR or at least do some of the tests to see exactly what is wrong.