SO I recently acquired a 90'prelude SI 4ws - Car is a lot of fun

it has a newer engine in it(stock b20a) but not all the hosses are hooked up-drove it today and it ran fine-got exactly 30mpg and i wasn't trying to get really good milage -the problem is the Car when cruising around stays at like 2800-3000rpm and won't drop down even if you let off the gas-

when i'm coming to a stop and shift from 3rd-2nd-1st then the revs stay at 3000 or so then they will drop back down?

i ordered at manual for it-but what should i look for-engine runs great- somethings just cuasing the motor to keep the revs up sometimes-i tried to adjust the idle which it idles fine now when in neutral but not when you put it in gear or when your driving

any ideas-i hope that made scense-its been a long day today-lol

 

Get all your vaccum hosed connected.

 

Yes, you have a vacuum leak. Fix the hoses