My idle would drop for about 10 seconds at a time so about 400rpm (confirmed on scanner) and would be very rough, and then go back up to the programmed 700rpm and stay there for up to 20 seconds, and then back down again. I got an EGR code. I swapped cams and removed the EGR, and the car is doing the exact same thing, it will run at about 900rpm for say 15 seconds and then dip to 500, and sometimes stall, I have a t56 now so this is in neutral.

I also need to give the car throttle to start it now. Valve lash has been set with the car running, I havent checked for arcing, though i dont think its the problem here. Does the EGR need to be programmed out even after removing it to avoid this erratic idle, or is this more likely IAC or something?

 

Since you have a scanner to see the true idle then take a look at the IAC and see what its doing.

 

EGR doesn't operate at idle or WOT. I'd check the IAC.

 

i will have to get my cable back. The scan i did last year shows the IAC counts at between 80 and up to 120 at idle, and it tends to stay in the 100s even while im driving, and even at WOT. I dont know much about these numbers, but is that like... way too high?? The idle was steady for the most part when that scan was done.