924Board.org

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

Just put a new head on my 924, old one was somewhat abused. Hogged out ports, recently spat out a spark plug while driving, damaged threads when it happened, stripped them trying to reinstall. Horray!

So I put a new head on, not sure which year it is but the cam pulley doesn't have the familiar dot as a timing mark, but instead a little groove machined into the edge of one of the pulley tooth grooves.

Here's where things get fun. I put on the new head, hook everything up as I've done a couple of times before, go to start it up and get.... nothing. It cranks and cranks and cranks and kinda sounds like there's some combustion almost happening but not quite.

I've got spark, I've got fuel, and it doesn't even sound like it's starting to catch. I'm thinking this must be a major timing issue somewhere. Had to change out the distributor with the new head of course, so the ignition timing is suspect. I have the dizzy aligned as per the haynes manual as I have done several times before. Rotor points almost straight at the firewall, canted slightly to the drivers side. Housing aligned with teh scribe mark next to the hall sender plug lined up with teh rotor.

Checked for spark, got it. Hall sender must be working then, correct? For some reason, I have two grooves on my crank pulley. One of them is a very slight machined looking groove which is somewhat V shaped. The other has been chiseled in it seems. Tried both, neither works.

Anyone else have or have seen the pulley with teh groove instead of the dot? I'm at a #### loss. I need my car to drive to Seattle next week.

Anything else I'm forgetting or missing here?
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'81 931 in various states of assembly

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

Just make sure here. At TDC for the #1 cylinder, the rotor should be pointing roughly at the #1 post in the distributor correct? Then it's #2-3-4 in a clockwise pattern. Right?
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'81 931 in various states of assembly

Ozzie · Posted: Sat Jun 24, 2006 3:58 pm Post subject:

1 3 4 2 else misfiring all round except 1
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Lizard · Posted: Sat Jun 24, 2006 4:00 pm Post subject:

no you have the firing order wrong, it should be at TDC with the valves closed for the #1 cyl you will then have the rotor pointed at the notch on the dizzy housing,
the iirc the rotation is CCW, but turn the engine over with a breaker bar to confirm rotation, then you will put the wires on in firing order 1-3-4-2
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3 928s,

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

The camshaft pulley is keyed, and they are interchangable between years, so if you have a hard time figuring out if the mark is correct, or you don't trust it, use the camshaft pulley from your old head.

The distributor position is keyed off the camshaft, so if the camshaft timing is wrong, so will be the ignition timing.

augidog · Joined: 03 Mar 2003 Posts: 1360 Location: New Jersey

I just went through this. The guy who did my head also put the cam on and cam pulley.
After not starting and frustrated I noticed he put the cam pulley on backwards!!!!!
I was using the outside timing mark that is not in line with the correct inside mark.
Take a look and see if there is a timing mark on the outside of that pulley and that it may be on backwards.
Good luck
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1978 924 95 mile daily driver.
Audi TB/POR174M/High Flow Cat/2.25" exhaust
I knew that positive thinking thing wouldn't work.

leadfoot · Posted: Sun Jun 25, 2006 12:37 am Post subject:

pull the no 1 spark plug, put a dowel into the chamber and turn the crank pulley until the dowl is at the top of the bore. replace spark plug. crank is now at tdc. It should also line up at the flywheel inspection hole with the correct timing mark.
remove oil filler on the cam cover , or remove the cam cover if you have new gaskets and check cylinder 1 tappets intake / exhaust are up in their bores indicating that the valves are closed. This will be pretty close to tdc of the cam, check your mark lines up close with the pointer on the cam cover. If it's not then the timing belt needs to be reset with the cam dialed in properly.
Leadfoot
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1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

Benji0301 · Joined: 18 Sep 2005 Posts: 66 Location: UK

Just to check what you said the timing order is 1-3-4-2 but the rotor arm moves in a counter clockwise direction? Is that correct? I havce mine set up 1-3-4-2 but the leads are set up clockwise on the distributer cap. Have I got it wrong?

Ozzie · Posted: Sun Jun 25, 2006 12:26 pm Post subject:

Looking down on the dist it goes clockwise.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

Lizard · Posted: Sun Jun 25, 2006 1:34 pm Post subject:

I got the 924 running, he had a loose wire on the coil and didnt have the dissy setup properly.
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3 928s,

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

Nah I checked the coil connections before, it must have come loose when we were #### around with it.

That is a totally different position for the dizzy than I had it in before, must be a tooth or so out from the position I had it in before.

Thanks to all who helped, especially Lizard.

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'81 931 in various states of assembly