so a lil over a yr ago i replaced my intake manifold on my 96 with a PI manifold with the aluminum crossover..(my thermostat housing had cracked) now ever since then every now an then when the car is hot an i shut it off and then try to turn it back on it gives me alot of trouble and then once started it idles real high an eventually it gets back to normal after a min..its like its over loaded with fuel.i have come to the conclusion it is either the fuel pump or the fuel pressure regulator..but now im back to square 1 cuz it doesnt make sense that it only started after i replaced the manifold.. so just today i was thinking and im pretty sure im wrong but is it possible that i would have needed a new tune for just the manifold? 2 me the manifold looks identical except for the aluminum crossover but what is so different?

 

The manifolds are different. Might want to get the a/f checked out.

 

If you are not using PI heads, adpator plates, or heads to change your NPI to the PI ports, then there is a decent port mismatch since the NPI heads are more tear drop shaped while the PI are more square.

 

well that is a usefull piece of info that i had never really heard..i realized that the ports are different shape..but never realized the mis-matching part.. now where can i get the adaptor plates an do you kno how much they might cost

 

The mismatching comes from the shape. The PI ports are larger and square while the NPI is more round. So at the corners of the PI port, the NPI port is blocking that since it a different shape. Think of a square w/ the length of sides as that of the radius of a circle. Overlap the two and the corners of the square aren't touched by the circle. However, you could fix this by just reshaping the port at the entrance w/ a Dremel. Also, HPS sells adaptor plates, not sure on cost though.

 

have you considered popping on a set of PI heads? they're worth 40-60hp or more as a straight swap. You'll need a tune and be stuck with 91/93 octane fuel requirements but the power is killer.

HPS plates would be my $.02 if you want to stick with NPI heads.

 

i have considered it.. but im planning to sell this car come spring and pick up a 99-04 gt...and maybe you can give me a link for those plates, the only thing i have seen is complete kits for the manifold an everything...

 

It's on their order page ($85).

 

www.hiperformancesolutions.com

 

thank you..i diddnt even know what hps stood for so i was a tad confused thans r3dnek

 

Oh, sorry about that, I just assumed you did.