i have a 91 hatchback with a d15 in it and it has a vacum leak. but the problem is that ive changed all the vacum lines and it stillhasnt fixed the problem and the only time my rpm's fluxiuate is when im at about 2000rpm and i think it might be my intake manifold gasket but im not too sure so any help will be much apreciated. thanks.

 

pull your IACV off and clean it....also make sure you have the vacuum lines goin to the right places...you may have them all connected, but if their not on right, than you will still get a fluctuating idle

 

Linky for removing and cleaning IACV?

 

i used this...for OP , the same steps apply for the d series
http://www.g2ic.com/forums/showthread.php?t=35534

 

better yet here is one for the d series
http://www.d-series.org/forums...35543

 

this is my single cam turbo i have a eg with a h22 but thats not the one that im having troubles with

 

so then i wont have to change my intake manifold gasket?

 

To check for vacuum leaks, spray some carb-cleaner over the suspected gasket/line and if the idle jumps up then there is a leak there.