Did B20B swap with pr8 head in my last civic and i have had no end of problems getting it to run right, at a stop it will rev up to about 3000rpm and back down constantly. also sometimes it wont start up after driving unless you leave it for about 10 min. list of mods were wire tuck, skunk2 intake aem fuel rail and fpr, dc header, 3'' exhaust dc integra ecu obdo to obd1 ecu conversion and obd2 engine harness converted to run on obd1 ecu.engine was a fresh rebuild as well. any imput would be greatly appreciated.

 

Problem one sounds vacuum related. problem two could be linked to a plethora of things...who did the wire tuck? Which OBD1 ecu? etc...the problem(s) start with what was removed and converted.

 

Might sound stupid but put your foot behind the gas pedal and pull it up. See if it helps.