Engine Hesitates On Startup

[tinmann840]

I just swapped the engine out in my 2000. The old motor had lost compression and would not start so I opted to buy another motor, gas tank (painted to match) and internal fuel pump. The engine came as a kit with everything including radiator, oil cooler, throttle bodies, ecu, harness and stock headers. I installed the new motor over the holiday and when it starts it hesitates then fires up and idles and revs normally. The idle speed is kinda of low, just at or a tad bit below 1000 rpm. I changed the plugs, oil and filter and coolant plus I'm running Seafoam in it at the moment. I'm wondering if I had some vacuum lines attached wrong. Another annoying issues is I left the stock headers on and I'm using some Tsukigi racing slip ons I've had forever. The thing is I didn't have the Bolt, cushion and spacer that mounts the stock headers underneath the engine and the vibration is making a irritating noise.

[dadofthree]

What year motor ? Adjust the idle up to 1250-1300 RPMs.

[tinmann840]

It's from a 2005. It's smoothed out considerably, fires right up. I ordered he hardware I was missing for mounting the exhaust and I also needed the sleeve that fits inside the gas tank bracket and one of the rear seat grab bar bolts.