I had just rebuilt the top end of the engine after having an engine fire which resulted from a screw at the end of the lower fuel rail falling out. The vehicle has idled high at around 1500 before but now it isles at around 2200. We’ve plugged many possible vacuum leak areas with no results and I’m not sure if our throttle cable and idle screw was messed up while reinstalling. We possibly blew a custom gasket for the intake manifold which could cause a major vacuum leak but I’m unsure. Any suggestions?

 

Yes, boost/vacuum leak test. I detailed two common methods in another thread within the last few days if you're unfamiliar.

1. Spray combustible aerosol.
2. Soapy water and pressurize the intake side of the engine.

 

Thanks for the input. I’m going to try and get a smoke machine on it to check for any new leaks and I’ve never heard of using a boost test for it but I guess I’ll check it out. Hopefully it’ll work

 

If you have access to a smoke machine, more power to you! Most people don't, so that should make quick work of any leak bad enough to affect your idle.

 

yeah I’m pretty lucky. I have a friend Who owns a mechanic shop in Sioux Falls, South Dakota. He’s pretty busy but I should be able to get the car in in about a week. I’m just upset because the high idle is preventing me from shifting into reverse

 

While you await time in your friend's shop, disconnect the throttle cable completely.
It is unnecessary for what you're doing and removes misadjustment as a cause.