924Board.org

[roybert]

Hi all,

After quite a while sitting fairly idle I managed to get around to doing the finishing work on my 924. I kinda made a bit of a mess of it so I got a mechanic mate to help me out. However all is not well, here is what we did.

Replaced timing belt
Replaced alternator belt
Flushed coolant
Replaced air filter
Replaced Water pump

However after doing all this the car wont fire up, we are fairly sure we got the timing correct (at the time) but I am starting to think its not right.

The battery is all good (getting a spark) and fuel is being delivered but its not firing up. In regard to the timing we used the notch on the top pulley and the notch on the bottom pulley. I lined up the zero on the mark thats on the flywheel. I couldn't find the one of the clutch though. I have the Porsche service manual and I was using the diagrams on page 82 if that helps.

Any help or ideas?

[ideola]

Put the crank at TDC using the mark and pointer on the front crank pulley.

On the cam sprocket, you need to use the correct mark. There is a dimple on both sides of the sprocket. To complicate matters, if the sprocket was ever put on backward, you could be looking on the right side but using the wrong mark! The dimple you want is on the side of the sprocket that has the VW/Audi mark and other writing on it. This side of the sprocket should be facing the windshield NOT facing the front of the car. So make sure your sprocket is on the right way 'round, and make sure you are using the correct timing mark.

Once you have that sorted, the other common mistake is to install the distributor incorrectly, or the plug leads in the reverse order. The firing order is 1-3-4-2, and the distributor rotates CLOCKWISE.

To index the dizzy, put the crank at TDC, verify that the cam is also at TDC (if not, see above!). Then, remove the distributor (also remove the dizzy cap). On the lip of the distributor housing, just to the right of the electrical connection is a score mark. This is the indicator for the #1 plug lead. Rotate the rotor about a quarter turn to the right (clockwise) of this scribe mark. Then insert the distributor. The rotor should now be just about point at the scribe mark. Rotate the dizzy housing until you have it perfectly lined up. Note that the vacuum housing may interfere with the valve cover in certain orientations, so you may have to attempt it a couple of times in order to achieve the best orientation. Once you have the dizzy properly in place, lock it down. Reinstall the cap, remembering which lead on the cap the rotor is pointing to. This is the #1 spark plug lead. Connect the leads in 1-3-4-2 order.

The car should fire, assuming you have fuel spark and no massive vacuum leaks.

Good luck!
_________________
erstwhile owner of just about every 924 variant ever made

[roybert]

Thanks for the quick reply! The dizzy was changed and neither were the spark plugs since we did the service. So that rules out that stuff and they plug leads.

The dimple on the bottom pulley was on the side closest to the windscreen but its very small dimple and we found it hard to find. If their is vacuum leaks what can we do?

[ideola]

Honestly, I think you're in the situation where you can't afford to assume anything. MAKE CERTAIN the cam sprocket has the writing facing the windscreen. If it's the other way round, and you're using the dimple on the back, you've got it mis-timed. I would also strongly suggest reindexing the distributor. It's so easy to do, why not do it just to be certain it's right?!

RE: vac leaks, the place to start is to check all of the large intake rubber & plastic boots, make sure there are no obvious holes or cracks. Then check all of the small 4mm vac lines. Make sure everything is connected, no loose ends, and no cracked or fraying lines. Ideally, you should replace all of the 4mm lines with new silicone lines. Don't bother replacing with the OEM cloth braided crap lines. They deteriorate too fast.
_________________
erstwhile owner of just about every 924 variant ever made

[roybert]

[ideola]

Awesome! For the battery drain, you should systematically check ALL of the relays. Sometimes these old relays will stick closed even after the power has been removed which will leave a closed circuit that can drain the battery. This is especially true in areas where there tends to be lots of moisture...

To be systematic about it, remove half of the relays. If the problem goes away, then you know the problem is in one of the relays you removed. If not, then the problem is with the relays that are still in. Keep halving the relays that are in until you isolate the problem relay. Be particularly suspicious of any relay that appears to have water stains or rust on it.

If you have power windows, then the problem is most likely a bad connection or a buildup of corrosion or crud in the switches themselves. These can take some time to chase down, so again, be systematic and thorough. Start by cleaning the two ground crowns up under the dash (stick your head under the foot well, grab a flashlight, sandpaper, emory boards, needle file, dielectric grease, remove leads, clean grease and reconnect). The next thing to address is the harness connection behind the kick panels. Remove the rubber bellows, fish the connection through the hole, disconnect all of the leads, and give them the same treatment as above. Next, clean the connections at the window motor. Finally, remove the switches, disassemble them, and clean them as well. If that doesn't fix the problem, then you either have a blown fuse, a bad relay, a bad switch or a bad motor. Replace in that order to minimize cost

Good luck.
_________________
erstwhile owner of just about every 924 variant ever made

[roybert]