Vn - Rough start & Rough Running Below 2k

[ghog1726]

Hi, iv recently changed the motor in my vn now since iv put it in the engine light is on (which never bothered me coz it WAS runnin alright), however now when i start it it idles reallllly low. as in 500 maybe less for anywhere up to 5 seconds. then jumps up to about 1500 then slowly goes down to a more reasonable idle, the problem is when i come to a stop at a set of lights or something similiar it also does this and when i accelerate unless i boot it splutters and coughs till about 2grand, then runs perfectly fine, any ideas?

[Not_An_Abba_Fan]

Do you have a vacuum leak?

Have you done an error code check?

[ghog1726]

hey, all fixed, silly me didn't have the vacuum for the map sensor plugged on, fixed everything, then i had a bloody coolant leak but its fine now too lol

[HARVZ-6]

baha gona say exactly that..

my bro left it unplugged but vac line to motor blocked off..