Originally Posted by OVERKILL
Originally Posted by caprice_2nv
Originally Posted by s2krunner
LSPI is only issue with turbocharger vehicles. I think your motor just knocking on hills.
"Pinging" is usually pre ignition, and often occurs at low speed/high load. It happens in my 83 Caprice also and I checked and my EGR valve is completely dead. The reduced it by retarding the timing. It was like 6 degrees over spec and now it's only 1.5 degrees advanced.
How do you not call it lspi whether it is caused by timing over advanced, carbon buildup, high temperature, etc. There are many different causes of it. GDI and turbo engines are more prone to it. How do you say it isn't called lspi if it's not a GDI or Turbo, or it could be reduced by retarding the timing? That makes no sense to me.
His car could be a combination of the timing being slightly advanced, some carbon buildup on the valves, maybe a bit of buildup in the EGR passages also.
They are two separate phenomena.
-Pinging/knock/detonation is generally caused by too low an octane rating or too much ignition timing and the result is that "pockets" of air/fuel ignite when they aren't supposed to making a "ping" or "knock" sound
-Pre-ignition is generally caused by combustion chamber deposits, running too hot a plug or oil droplets causing the commencement of an ignition event prior to when it was meant to occur. Your old vehicles, if they've ever "run on" would be experiencing pre-ignition.
LSPI is a massively more severe version of the 2nd scenario where at low engine speed in a forced induction direct injection engine something causes the air/fuel mixture to be ignited before it is supposed to causing a severe explosive event that can severely damage the engine.
I was unclear on this difference. My 230k mile 305 never "runs on" or "diesels" but I have a friend in South Carolina with a 330k mile 305 in a 77 impala and his diesels if he doesn't shut it off in drive. His also had slightly too high of an idle and I didn't actually hear any pinging when he took us for few hundred mile trip in it while we were visiting. It was like 95 degrees that day too.
Originally Posted by caprice_2nv
Originally Posted by s2krunner
LSPI is only issue with turbocharger vehicles. I think your motor just knocking on hills.
"Pinging" is usually pre ignition, and often occurs at low speed/high load. It happens in my 83 Caprice also and I checked and my EGR valve is completely dead. The reduced it by retarding the timing. It was like 6 degrees over spec and now it's only 1.5 degrees advanced.
How do you not call it lspi whether it is caused by timing over advanced, carbon buildup, high temperature, etc. There are many different causes of it. GDI and turbo engines are more prone to it. How do you say it isn't called lspi if it's not a GDI or Turbo, or it could be reduced by retarding the timing? That makes no sense to me.
His car could be a combination of the timing being slightly advanced, some carbon buildup on the valves, maybe a bit of buildup in the EGR passages also.
They are two separate phenomena.
-Pinging/knock/detonation is generally caused by too low an octane rating or too much ignition timing and the result is that "pockets" of air/fuel ignite when they aren't supposed to making a "ping" or "knock" sound
-Pre-ignition is generally caused by combustion chamber deposits, running too hot a plug or oil droplets causing the commencement of an ignition event prior to when it was meant to occur. Your old vehicles, if they've ever "run on" would be experiencing pre-ignition.
LSPI is a massively more severe version of the 2nd scenario where at low engine speed in a forced induction direct injection engine something causes the air/fuel mixture to be ignited before it is supposed to causing a severe explosive event that can severely damage the engine.
I was unclear on this difference. My 230k mile 305 never "runs on" or "diesels" but I have a friend in South Carolina with a 330k mile 305 in a 77 impala and his diesels if he doesn't shut it off in drive. His also had slightly too high of an idle and I didn't actually hear any pinging when he took us for few hundred mile trip in it while we were visiting. It was like 95 degrees that day too.
