Idle trouble started after Ford replaced front engine gasket on my '95 in the signature trying to solve a coolant loss problem. They are trying to find it, but have not solved it yet.

Basically, now start up of engine RPM is about 2000, drops to 1100, and never goes lower. Previously, start up was about 1600 and dropped to 800. It is also kind of "shakes" the truck- not a lot, but it did not do that before. They said they adjusted the timing a bit to get it down to 900, but when I went over there to check it out, the idle drops about 100 RPM if I step on the brake pedal, and it hesitates if I step on the gas.

I know they need to find the trouble, but I need my truck back. Do you think they put something back together wrong or created a vacuum leak somewhere? I am having little comfidence in them because when I went to pick up the truck, they did not have a hose connected to the air pump, and it was missing a support bracket that connected to the intake and exhaust manifold.

Thanks for your input.

 

It sounds like a vacume leak to me. The brakes use vacume in the power system and that could be making the problem worse when you hit the brakes.
Start with all the vacume hoses first. They may have hit one while working on the engine and caused it to leak. Use needle nose pliers and grab each hose just before it enters the block on the intake side. If you hit the right one, the engine will calm.
Good luck, hope this helps.
FYI if the vacume leak is from an improper seal from the engine work, you may need to pull the intake and re-seal everything.