From what I have found out if the EGR is not working or is disabled the ECU will retard the timing to help eliminate detonation since the EGR system is not working. Can anyone confirm this?

The reason that I am asking is that I am trying to decide whether or not to remove my EGR system. I know that the EGR is supposed to help lower the temps in the combustion chambers while at cruising speeds. But I disconnected the vacuum line to the EGR to see what effect it had on my EGT readings (the EGT's dropped by about 75 degrees). Maybe this is from the timing being retarded?

Currently I am in the process of hooking up my Megasquirt that I will be using to run fuel only at this time, but I may eventually use it to control the timing and if I do that I doubt that the EGR will work anyway with the factory ignition disconnected. But I may leave the EGR hooked up while I am using the factory ECU to control timing if removing the it will retard the timing.

Any input on this would be appreciated.

Thanks.

Joe

The EGR valve opens only at part throttle applications to reduce emissions (NOx specifically, NO2 and NO3, don't we wish it would form NO!). At WOT it is closed, so it should not have an effect on timing when you are at full power.

I'm not sure why you are seeing lower EGT though, but I would just block off the EGR and not worry about it, especially since you'll be running the megasquirt anyway.

Originally posted by BOOSTED ECLIPSE
From what I have found out if the EGR is not working or is disabled the ECU will retard the timing to help eliminate detonation since the EGR system is not working. Can anyone confirm this? The reason that I am asking is that I am trying to decide whether or not to remove my EGR system. I know that the EGR is supposed to help lower the temps in the combustion chambers while at cruising speeds. But I disconnected the vacuum line to the EGR to see what effect it had on my EGT readings (the EGT's dropped by about 75 degrees). Maybe this is from the timing being retarded? Currently I am in the process of hooking up my Megasquirt that I will be using to run fuel only at this time, but I may eventually use it to control the timing and if I do that I doubt that the EGR will work anyway with the factory ignition disconnected. But I may leave the EGR hooked up while I am using the factory ECU to control timing if removing the it will retard the timing. Any input on this would be appreciated. Thanks. Joe

yeah but how can you get away with removing the exhaust gas recirculation (EGR) valve on a 98?? wont you still have to do emissions?

You are totally awesome raptor. A true role model.