Well here is some insight. It doesn't have a crankshaft sensor in this year, that didn't start till 95 or 96.
Now that knock sensor is needed in the system because of low octane fuel, incomplete fuel combustion, which is bad for your motor and emissions. What is happening in your motor is it's getting two firing sequences one too far before tdc "the ping" and another with the spark plug. If this isn’t fixed it could burn a hole in the piston or burn the exhaust valve, go easy on this motor until it’s fixed.
What you can do in the mean time is adjust the timing by ear under load until the ping goes away. You need two people and it’s a little dangerous, the experts here wouldn’t tell you to do this. But one person puts the truck in gear and holds the gas peddle down until you hear the ping and turn the distributor ever so little until the ping goes away and runs strong and idles good. This is called timing by ear...
It would be better and safer to hook up the knock sensor so it works like it should...
RE: catalytic converter I don’t think you have a problem there unless it gets real hot and your exhaust flow is low.
The EGR system is still something to look into if you're still having trouble.
Good luck, and don’t hurt your self...
Saturday, February 18th, 2012 AT 12:44 AM