Please help! 1990 galant surges at idle and will not stablize!

[DSgalant04]

I hoping somebody out there can help.
When the car first starts its fine but after it warms up the idle will rise to 2500 RPMs and then drops down to 1200 & then starts surging
I cannot spend to much money on fixing it because of low income
so please if somebody know how to fix it contact me at [email protected] or post a reply Thanks I would really apreciate it!

[TheScout]

describe the surging a little bit more in depth. How high is the surge? any modifications to the car? last maintenance and what was done (aside from oil change)

[gsx0oner17]

well if ur rpms go from 2500 down to 1200 and if it goes back up to 2500 again then down to 1200 and repeats itself then its most likely the EGR valve. but please explain the surging symptom