sam2.0 10 Posted March 5, 2013 On my 9A 2.0 16v I'm having issues with my timing and I've read a load into where the fly wheel should be at. I've read/heard the following: The line is TDC, a square mark is BTDC BTDC is a '0' BTDC is 2 teeth clockwise from TDC BTDC is 3 teeth clockwise from TDC Insert more here Now, my flywheel only had the straight line mark, which I believe to mean TDC. The engine runs on it, but its lumpy, so clearly not right. The attached diagram shows BTDC to be 2 teeth clockwise, but other people have mentioned 3 teeth. So, What position do I put the flywheel in for BTDC (6degrees)? [ATTACH=CONFIG]72685[/ATTACH] Quote Share this post Link to post Share on other sites
davidwort 0 Posted March 5, 2013 (edited) O is tdc, the other mark, usually a thin line is 6 degrees before tdc, depends if you have an advance adjustable timing light or not which one to use, I've seen several 4 cyl corrados but never one missing the O tdc mark. Edited March 5, 2013 by davidwort Quote Share this post Link to post Share on other sites
sam2.0 10 Posted March 5, 2013 I don't have a timing light, so best to setup on the line. To find TDC, is it 2 or 3 teeth along? Its currently 3 teeth from the line (as I said, I've read the O is the TDC), as was trying to find BTDC! Quote Share this post Link to post Share on other sites
Yandards 0 Posted March 5, 2013 You won't get it to run well without a timing light frankly. As for the distance from the 0 deg mark, the workshop manual states that 6 deg BTDC is 14.5mm to the left of the 0 deg mark. Quote Share this post Link to post Share on other sites
bmwcompact 10 Posted March 5, 2013 I have only 1 mark on my 2l 16v 9A engine flywheeel. The illustration you show is what I expected -I dont have it-I've looked very, very carefully. I take my single mark to be TDC and set up my valve timing with it last Summer when I changed my belt. I used a strobe to set the ignition timing 3 teeth adrift of this -supposedly 6 degrees BTDC. Now that you have found a mark on your flywheel have you turned your engine in the direction of rotation and confirmed that the cam marks, the cam pulley mark, the rotor arm pointing to dist mark, and the single TDC flywheel mark all line up? Until you've done this you cant be certain your valve timing is correct. You may need to adjust the belt. If you then set your ignition timing the engine should run fine on 2 or 3 teeth advance -being out a little shouldn't make the engine run lumpy. I am sure that by now you must be pretty brassed off after all the time /effort you've expended, so I don't want to appear to be rubbing salt in your wounds, and wish I could solve your problem. My concern here is that you have had several separate posts covering one event. By reading these, it appears you've replaced your head gasket but I don't know what issue you had with the car that caused you to do this. You then had a broken key on your cam pulley. You have then started 2 separate posts about flywheel marks. Throughout all this I have no idea when the engine has been turned by hand and when its been started. I suspect you've lost the relationship between cam and crank and at some point done some damage to your valves. I hope I'm wrong! Forum members who are only aware of this post will simply think you need help with ignition timing. Quote Share this post Link to post Share on other sites
sam2.0 10 Posted March 5, 2013 (edited) Thanks for the reply. I have set it up twice on the line now, and also at -6degrees. It won't start on the line, and does start at -6 but is rough (I done it to 3 teeth excluding the one with a line on) The gasket was changed due to a water leak into Cyl1. The only timings I've done as as above, so I'm hoping nothing is damaged. I've just set it to the line again (from scratch) and still no go. I'm now starting to think something else is up! It cranks and the starter motor is turning the engine, but no ignition in the chamber. I get sparks and fuel seems to be making its way. Edited March 5, 2013 by sam2.0 Quote Share this post Link to post Share on other sites
davidwort 0 Posted March 5, 2013 That sounds ominous, no compression would mean no burn and could be a bent valve :( Quote Share this post Link to post Share on other sites
sam2.0 10 Posted March 5, 2013 Would it not fire but be a rough idle? Suppose several could be bent. I'll buy a compression tester tomorrow :( Quote Share this post Link to post Share on other sites
davidwort 0 Posted March 5, 2013 Just whack the plugs out of 2,3,4 and turn the engine over with a socket on the crank pulley bolt, you'll feel the compression if it is sealing on no. 1 Quote Share this post Link to post Share on other sites
