1997 vortec 350 - high idle

[GEARJAMMER1986]

Hello, hows everyone? lol. I just took my upper intake off to replace my fuel pressure regulator, put everything back together, and now, I have an extremely high idle. While in park or neutral, my idle is now between 1200 and 1500 rpms and i dont know why. I cleand the throttle body with crc throttle body and intake cleaner. In drive, the rpms go to about 900. Somethings not right. The old fuel pressure regulator was leaking pretty bad, So thats why i replaced. It fires right uyp everytime now, but dont know why my idle is high. Any help would be appreciated on how to adjust. Thanks so much

 

[deerejohn]

check the cruise cable to see if its not bound up. keeping the throttle open.

 

[livingez_123]

Vacuum leak?

 

[99Yukon4x4]

I'm going with vacuum leak as well. My 99 Yukon is doing now as well. I seem to have misplaced one of the bolts for the plenum, and is idling higher than normal, but settles down after a few minutes. The seal for the plenum cover may have come dislodged, or mangled, and/or the seal where the electronic plug (next to fuel lines) may have been damaged.

 

[SunlitComet]

You should spray some starting fluid with a straw on the can around where the seals are to narrow it down quickly but always make sure you replace those seals and oil the up before going in. I know the spider oval o-ring can make it difficult to get the plenum to go down and fully seat.

 

[surgical-grade]

Hello, hows everyone? lol. I just took my upper intake off to replace my fuel pressure regulator, put everything back together, and now, I have an extremely high idle. While in park or neutral, my idle is now between 1200 and 1500 rpms and i dont know why. I cleand the throttle body with crc throttle body and intake cleaner. In drive, the rpms go to about 900. Somethings not right. The old fuel pressure regulator was leaking pretty bad, So thats why i replaced. It fires right uyp everytime now, but dont know why my idle is high. Any help would be appreciated on how to adjust. Thanks so much

My '96 tahoe did the same thing. I replaced the lower manifold gaskets, and she idles perfectly now.

I've read that those gaskets/high idle are a very common problem in the 96-99 vortecs.