hello, i have just done the head gasket on my s2 and while i was at it i rebuilt the head which included a new standard ford cam, followers, lifters,valve stem oil seals. I gave a service aswell. I have just finished putting it back together and after the fuel pump not priming i renewed the relay and that sorted that problem. Now when i go to start the car it doesent start unless i get someone to push the metering flap down slightly then it runs ,but runs a little rough and seems like it running on 3 cylinders. once the cars running you can let go of the metering flap and it will run like this for maybe 2 ,3 mins then the revs will drop and it will die. So far the dizzy has been put back in the exact place it was when it was taken of, the leads are new and are in the right order, plugs are new aswell. Ive checked the timing and all of the timing marks line up. Also When it was running there was quite alot of blueish smoke, the valve stem seals are new and the turbo is ok and didnt smoke before i did the head gasket. I put in some new oil which was 5w40 this is ok isnt it. Can anybody help me please the car is driving me mad now.
cheers.

 

You have an air leak mate, check boost hoses, breather hoses etc...

 

checked every boost hose, breather and cant find an air leak. The flap also bobs up and down when you crank it over so not sure if it does has one. Any more ideas.

 

the flap should bob up and down which is a good indication that there is most likely no air leaks. is it the same cam as before i.e standard before and after and have you held the revs around 2000 for atleast 10 mins to fill the tappets up on first start up, it could just need a set up now the things been tampered with especially if it was set up to run on a knacked old cam and now everything is as it should be and did you get the head skimmed etc before re fitting

 

Oright, Yes i did have the head skimmed and the cam i took out wasent that bad. I only had it started by someone pushing down the metering flap slightly then it did run but sounded slightly rough and after about 15 seconds the revs would drop down and i would have to press the flap again slightly and the revs would shoot up and drop back down again and it will keep running but i have to stay by the flap and push it every 20 secons when the revs drop. Because of it not running properly yet i havent had chance of bedding in the cam.

 

There is only one reason that pushing the flap down keeps it runing and that is that you are lean.
If you've had the head off etc... then normally an air leak where a hose has not gone back correctly, but could also be that the idle mixture is wrong, try turning the idle mixture screw 1/4 of a turn at a time clockwise see if that helps (if not return it to the starting position!).

 

right will try that tommorow, cheers pal