machinehead
Newbie
- Joined
- Feb 12, 2015
- Messages
- 13
- Reaction score
- 9
I have a 1996 k1500 5.7 with 234,000 mi. I have had it 21 years, so i know her pretty good. I have been driving 80 miles a day for work in San Antonio. in the mornings its about 70 and humid outside. The truck runs great. on the way home its more 95 and i have been getting some spark knock. Its mainly going up a grade when the engine is kinda chugging along and speed is slowing down. i have been scanning while driving and have noticed when its pinging my spark advance is down to -1. here are some data points. when it was doing it up a gentle long hill and the gear stayed in overdrive.
RPM 1783
Speed 62
ignition timing for #1 cylinder -.5
Air intake temp 124
throttle position 53%
i don't have many hills going to work but here is a snippet of morning. just strait away easy driving.
RPM 2022
speed 71
ignition timing for #1 cylinder -33
intake air temp 78
throttle position 26.27
I did get a p 1406 the other day for EGR pintle. i have a new delco EGR on the way. i also have some of the seafood top end cleaner that has the long hose to spray into the throttle body. i replaced the knock sensor and the connector end last weekend, that didn't change anything. i have heard the EGR can cause problems with spark knock without setting codes off. I'm going to do a top end clean before changing the EGR. the plugs, wires, cap, rotor were all changed 34,000 miles ago. the coil is original.
Thoughts???
RPM 1783
Speed 62
ignition timing for #1 cylinder -.5
Air intake temp 124
throttle position 53%
i don't have many hills going to work but here is a snippet of morning. just strait away easy driving.
RPM 2022
speed 71
ignition timing for #1 cylinder -33
intake air temp 78
throttle position 26.27
I did get a p 1406 the other day for EGR pintle. i have a new delco EGR on the way. i also have some of the seafood top end cleaner that has the long hose to spray into the throttle body. i replaced the knock sensor and the connector end last weekend, that didn't change anything. i have heard the EGR can cause problems with spark knock without setting codes off. I'm going to do a top end clean before changing the EGR. the plugs, wires, cap, rotor were all changed 34,000 miles ago. the coil is original.
Thoughts???