I just finished upgrading my secondary fuel rail, But now when the car is idleing it surges between 500 to 1000 rpm. The car never did this before so im guessing it has to do with when i removed the UIM but im not sure. The injectors were installed yesturday. When i first started the car it idle fine untill it warmed up then it started to surge and it did it this morning. If anyone has any info i would appreciate it.

Thanks,

Also, last time i removed the UIM it did the same thing but the surging went away the next day.

 

Sounds like a leak in the induction mate, check everything is tight from the turbo outlets to the LIM, and if you cant find anything spray the joins with water - when the idle settles, youve found your leak in what you just sprayed.

 

id spray it with brake cleaner to try and find leaks. make sure ur vacuum lines are all hooked up. Tighten the throttle cable.

Did you upgrade the injectors? or just install a fuel rail.

 

Upgraded injectors from 850 to 1600

 

make sure they are seated properly and the orings aren't pinched. Also did you hook up a new Fuel Pressure Regulator? Or are you using the stock one that uses the vacuum line that runs to the UIM?