32 replies to this topic

[dsl-productions]

hi guys, im new to the forum, this may sound a stupid question as a mechanic, but i just changed my head gasket after comming back from santa pod mitp, and now my mini wont start, iv diagnosed it as what i think is the firing order has mysteriously changed is as if when it should fire on one cylinder its trying to fire a different one, can anyone help me as too what the firing order on the cap and the engine is please, also if possible how to identify the position of which the rotor arm should be in to fire in the right order, its for a standerd 998cc A-series engine
thanks guys kris

[Andy!]

Pretty sure it's 1-3-4-2 Thats what my dads mini and my mini was. Sorry thats about as much as i know.

[Bec]

http://www.theminifo...howtopic=139119 <<good picture

[minimender]

yes its 1342 one being at the radiator end.

Number One on tdc with both rockers rocking (firing stroke) rotor arm should be about ten past the hour as you look at it.

[Ruckus]

Find TDC on cylinder 1 (nearest the rad), whatever the rotor arm is pointing at, That is 1, firing order is 1 3 4 2.

To find TDC:
Remove the plug cylinder 1.
Put the car in gear with the handbrake off
Move the car forward with your finger over the hole.as it starts the compression stroke you'll feel pressure on your finger
Then get a screwdriver and stick it in the hole...slowly move the car forward when its reaches it highest point that is TDC.

[Guess-Works.com]

or....

Get the engine to TDC, and the rockers on number 1 cylinder's valves should be loose, and likewise the rockers on number 4 should be tight ( on the rock )... This is the fire stroke for number 1

[dklawson]

Moving away from the firing order issue, remember that when you fit a new head gasket you must also re-adjust the valve clearance. If you don't perform a valve adjustment you are likely to not develop good compression and the engine will not start. Also, since the head has been off you will have disconnected the intake and exhaust manifolds. Make sure they are properly seated with a new gasket and that there are no gaps that could allow a vacuum leak.

[dsl-productions]

thanks guys for all your advice i will now crack on with re-adjusting the valve rockers and double check everything for the vacume

thanks very much
kris

[TAR]

Not sure if you touched the distributor, but it is possible to put it in 180 degrees out. You will soon see this if the rotor arm is not pointing at the lead for cylibder 1 when piston 1 is at TDC.

[billzer]

hi all im also doing a head gasket all done tuorqed ect, do i need to find tdc when adjusting the tappets on a mini cooper mpi ?,

[dklawson]

The answer is basically "yes".

There are several methods of how/when to adjust the valves. You will hear people talk about the "rule of 9" and things like that. For me, it is just as easy to mark and remove the spark plugs so I can look for the piston through the plug hole. Turn the engine over by hand until the piston is seen at the top of its stroke AND the rocker arms for that cylinder are "loose", then adjust the valves for that cylinder. Repeat these steps individually for each cylinder until all 4 are done. That isn't necessarily exactly TDC but it is close enough to adjust the valves accurately.

EDIT: And thank you for using the search feature to find this older thread on the topic you were interested in!

Edited by dklawson, 10 October 2012 - 11:54 AM.

[R1minimagic]

And make sure the spark plug leads are on the correct cylinders, easy to get them muddled up and create your own wasted spark system!!

Edited by R1minimagic, 10 October 2012 - 11:58 AM.

[billzer]

thanks guys

[Cooperman]

It's 'Rule of Nine' for me. If you turn the engine until a valve is fully open, subtract the number of that valve from 9 and adjust the one with the resulting number. So, if valve no.3 is fully open, 9 - 3 = 6, so adjust vsalve no.6.

[freshairmini]

I think the Haynes manual has that system in it. When I did my head gasket I just followed the guide in the Haynes and it worked fine.