high egt on decel

[billios996]

I noticed that if I take me foot off the gas from hi speed/rpm and coast under vacuum (~ -20 inHg) my egt's spike and pin the gauge until I goose the throttle a bit. I'm thinking ISC (2g) is either shot, or not set right. Any ideas?

[blcknspo0ln]

ISC only controls idle speed and decelerating speed (based on VSS also, should raise RPM slightly upon decel). I don't think the ISC would cause high EGTs though. What are you tuning with , Bill? If you're on SAFC I'm thinking maybe your LO settings are incorrect, but, then again, I've had fubared SAFC settings and they never did that?

[Nate Crisman]

when your above like 2000rpm and 0tps, the ecu shoud completely shut off the injectors and deliver no fuel. no fuel - no combustion - dropping egt. It's an emmissions/gas mileage thing, almost any efi car does this (even aem ems)

not sure if the auto 2g ecu doesn't do this, or if the "returning to idle" happens faster on an auto since the engine rpm drops.

[billios996]

This just started happening recently. I'm running the keydiver chip ecu, so AFC is zeroed out across the low settings. Perhaps the tps isn't reading 0 throttle position. Time to dust off the pocketlogger :D

Thanks guys!

[lithium]

I've seen EGT gauges do funky stuff when the probe goes bad... I've also had bad experiences with "re-using" EGT probes (probes going bad after removing and reinstalling).

[billios996]

I figured it out. The stoopid throttle plate is a little sticky and doesn't close all the way, hence never reaching zero throttle position. :roll:

[blcknspo0ln]

roll it off a hill :wink:

[billios996]

roll it off a hill :wink:

That's how I get my best traps :lol: