New engine not running right

[jefinabox]

Hi,

I've just put a new engine in my 172 cup, and fired it up for the firs time. It fires up ok, goes to 2000rpm for about 5 seconds then idles anywhere between 1200-2000rpm. The OBDII jobbie gives me a p0300 error for multiple misfires. I swapped the plugs over and checked all connections and they seem fine but it did the same thing. I haven't got the headlights plugged in and a few other bits because I wanted to check I had it all right before I put it back together so I don't know if this is a problem or not? Everything in the engine bay is present and plugged in. The new engine I put in was bare so everything's been reused from the old engine which ran ok except for a bit of rod knock lol.

The only other problem I can think of is that I snapped the big red cable's connector on the alternator and the nut just spins so that's not hooked up until I get a new alternator.

I made a video of what it's doing:

http://youtu.be/cakhYNzpxas

I'm a little stuck, does anybody have any ideas please?

Thanks

 

[scotty2hotty81]

Manifold on properly? Did you fit the seal at the bottom of it?

 

[jefinabox]

Hmm, seal? I fit the gasket between upper and lower inlet manifold. Or am I missing something lol?

 

[jefinabox]

Both the gasket and the little rubber seal are there. I tightened all the manifold bolts a little more and it stopped the revs pulsing but it stayed at around 1500rpm, so I'm going to order a new gasket and seal and see what that does. Still saying misfiring on the OBDII.

 

[Richard102]

Dont these clio have a throttle learn? When you disconnect the throttle body sometimes they need to... basically learn where normal idle is. Mine done this for about 30 miles after i fitted matched inlets and ported throttle body, and then was fine.