hello everybody, im doing this for a friend of mine who owns a 93 eg with b18c1 rebuilt block swapped obd1. i was trying to figure out what was wrong with the fluttering rpm at idle. he had bought it like that from craigslist.org

when he starts the engine. then rpm will go to 4k to 1k back n forth for 3 secs then it will reduce 3500 to 1k for few more secs, then lastly it will stay fluttering from 1k to apprx 2500 as it goes constantly at idling.

as he told me he had replaced cracked idle sensor. but other than that i have looked everywhere to see if there is anything wrong, but seems to find none.

i need help with all the possible solutions listing. that would help us a lot. thanks!

 

You probably have a vacumm leak somewhere in the intake manifold, check hoses, injectors o-rings, throtle body gasket loose plugs and even the fast idle valve under the throtle body, check and adjust the idle screw also.