Wierd things with idle and lights

[YuNg1's_240sx]

I got a new engine put it. It runs great and everything, but here is the problem: After car has warmed up when you come to a stop about every 20 seconds the idle will drop to about 4-500 rpms then return to normal 800ish rpm(occasionally it quits when it drops). This effects drivability in stop and go traffic its a b****. this is accompanied by the lights dimming and getting bright. It has nothing to do with rpm if i blip the throttle you will hear two fast clicks and lights will dim then bright or bright then dim. If I'm cruising and let my foot off the gas it clicks and lights go dim or bright. In other words it's constantly clicking and messing with the lights.this is really bothering me because i can fell and hear the problem. The lights go dim and rpm drops. I was thinkin loose grounding wire. but the thing is i dont know where to check.

[wackawacka]

What motor you got champ?

[YuNg1's_240sx]

a 97 ka.

[nightsauce]

almost sounds like the alternator...my car dips low but its from a dirty iacv

[AZ89two4Tsx]

I had this same problem when I turned my lights on and off. The idle would briefly drop.

Check your battery terminals. Make sure they are tight and not corroded. If they look bad, replace them. Fixed my problem.

[YuNg1's_240sx]

could an oil leak cause this?im not sure but it seems to be coming from one of the pumps, and getting on the belts and alternator and spreading it around.i know i have to get it fixed asap. cuz this basically the same way my other engine got shot, an oil leak.