mean in green Posted October 1, 2009 Share Posted October 1, 2009 This one is really beginning to cheese me off: intermittent and unpredictable, not to mention inconvenient. Turning the key to final position, all I can hear is a clunk from the starter (but it doesn't start). In trying to get to the bottom of this I have so far: Tried three different starters - problem still exists. Tried two different batteries - problem still exists. Cleaned the battery earth, terminals and connections - problem still exists. Cleaned the main engine to body ground strap connections - problem still exists. Checked the ring gear - no damage. Checked the plugs / connections under the dash. I have found that I can sometimes rock the car in gear and then it will start, but this isn't always the case and I then have to bump it. Any ideas what to try next? Link to comment Share on other sites More sharing options...
Jammo Posted October 1, 2009 Share Posted October 1, 2009 MIG, when you had the starter out did you have a quick ganda at the ring gear????? I would say electrical/starter, but if you have tried so many starters it's hardly that - but the rock in gear and then it starts, like if there is a 'bad' bit of ring gear the starter hits on. I know it sounds crazy but most engines come to rest at only a few positions, not just anywhere and this could be one of them bad bits. Are you sure though the box to body earth strap is ok though???? Gits these. Hope it helps. Regards Jammo. Link to comment Share on other sites More sharing options...
mean in green Posted October 1, 2009 Author Share Posted October 1, 2009 Yeah, I've looked at the ring gear and it seems ok Jammo. Is there an easy way to rotate the ring gear to inspect it? I'm not sure if that could be it - the other thing to note is that I never had this problem before it went into the body shop... I haven't replaced the 'box to body strap, just cleaned the connections up (which were very crusty). Link to comment Share on other sites More sharing options...
Fred Posted October 1, 2009 Share Posted October 1, 2009 it sounds like it is griping. have you tried WD40 on your starter motor? I have heard that it works. Link to comment Share on other sites More sharing options...
Jammo Posted October 1, 2009 Share Posted October 1, 2009 I usually get my Wife bent over the back end, with her head under the engine cover, this usually works. Whip out the starter (yours should be easy enough ) and mark the ring gear (I use tippex) Yell to the Wife to turn the spanner I put on the main crank nut and watch as she slowly turns it - you should get a good view of the ring gear meshing through the starter 'hole'. Once the tippex comes around you know when you have looked at all the ring. Your looking for badly 'ground up' teeth. OOooooerrrr, the ground strap could/can cause nightmares,,,, is the strap itself all crusty, grotty and hot looking? Since the body shop, what could they have disturbed, what did they do? Regards Jammo. Link to comment Share on other sites More sharing options...
mean in green Posted October 1, 2009 Author Share Posted October 1, 2009 I haven't tried that no Fred, but I'm not sure how it would help - the connections all seem good, and two of the starters tried are new. Your looking for badly 'ground up' teeth. OOooooerrrr, the ground strap could/can cause nightmares,,,, is the strap itself all crusty, grotty and hot looking? Since the body shop, what could they have disturbed, what did they do? Ok Jammo, will drop the starter off to properly check the ring gear. The strap itself isn't a picture of health - I could swap that out. The body shop put front wings on it and grafted lower 993 screen section in (i.e. dash out). Link to comment Share on other sites More sharing options...
Fred Posted October 1, 2009 Share Posted October 1, 2009 I haven't tried that no Fred, but I'm not sure how it would help - the connections all seem good, and two of the starters tried are new. I know, but I have heard miracle about it. Link to comment Share on other sites More sharing options...
REX Posted October 1, 2009 Share Posted October 1, 2009 I haven't tried that no Fred, but I'm not sure how it would help - the connections all seem good, and two of the starters tried are new. Double check the solenoid wire and the earths mate, check the resistance on the gearbox earth strap, can post you a new one. Link to comment Share on other sites More sharing options...
burgundyben Posted October 1, 2009 Share Posted October 1, 2009 (edited) The strap itself isn't a picture of health - I could swap that out. For a few quid its and easy thing to eliminate. Always replace the cheap bits first when chasing a fault. Edited October 1, 2009 by burgundyben Link to comment Share on other sites More sharing options...
mean in green Posted October 1, 2009 Author Share Posted October 1, 2009 Any idea what sort of resistance reading would be acceptable Rex - I tried that earlier and got 0.4 Ohms. I dunno if that's good, bad or useless? Link to comment Share on other sites More sharing options...
Jammo Posted October 1, 2009 Share Posted October 1, 2009 Ah, they have been working in the dash area..... what about the starter/ign switch and harness to that (lets hope they havent fried or climped it). Have you moved the main harness from the switch about when the problem occurs? That's worth an investigation.... If you can try a good earth strap at least you can forget that bit,,,, they cause so much grief, they really do. Regards Jammo. Link to comment Share on other sites More sharing options...
REX Posted October 1, 2009 Share Posted October 1, 2009 At 0.4 ohms there is no probs there, try the solenoid wire, buzz that out if you can. Link to comment Share on other sites More sharing options...
Northy Posted October 1, 2009 Share Posted October 1, 2009 Simon, I had a few intermittent starting problems which seemed to have stopped now. I think changing both the body to gearbox strap and the battery to body strap seemed to have helped. They are cheap, so you might as well do it anyway. I'd already tried cleaning up the connections, so I think maybe they had just started to break up or something? Link to comment Share on other sites More sharing options...
mean in green Posted October 1, 2009 Author Share Posted October 1, 2009 Yeah, maybe I'm just imagining it but it would kind of make sense: when I'm rocking the car to and fro in gear I'm probably also (slightly) moving the earthing strap just enough to let the current flow again? The strap does look very brown and crusty, even if I've cleaned its connections. Cheers for the tip Lewis - it's getting swapped now anyway, it's easier than replacing the solenoid wire... Link to comment Share on other sites More sharing options...
Roy M Posted October 3, 2009 Share Posted October 3, 2009 Are you definitely getting the 'starter clunk' I had a similar issue with mine and it turned out to be the immobiliser starter circuit playing up - ran a direct feed with a push button to check first but that was definitely the issue - rewired and no problems since Roy Link to comment Share on other sites More sharing options...
mean in green Posted October 7, 2009 Author Share Posted October 7, 2009 Yes the noise was definitely the solenoid on the starter. The good news is that I seem to have sorted this now: as with Lewis' the problem was either the engine to body or the battery earth strap (or both). New ones fitted and no problems hot or cold. Infact it seems very keen to start now too - literally as soon as the key begins to rotate, it's noticeably different. I found John at Cambridge Motorsports very helpful with it: when I 'phoned to say I was having problems he happily took the Edge starter back and ran it on a test rig, then also sent me a replacement out without any hassles. On the one hand I've unecessarily replaced my starter, on the other I'm not really bothered - the Edge one is a nice upgrade on the twenty seven year old original. What I'm not clear on is why it became more of an issue when hot, or why I could sometimes start it by rocking the car in gear (what originally made me think the first Edge starter was the problem). The original engine strap was slightly frayed out of sight on the car, and is reasonably exposed to the elements. Maybe my moving the car in gear rocked the engine on its mounts enough to flex the strap into a position where it would function? Does electrical resistance increase with temperature? Link to comment Share on other sites More sharing options...
jevvy Posted October 7, 2009 Share Posted October 7, 2009 I think its more likley that the starter was initially striking a tooth on the ring gear and didnt have the current to push past and engage in a slot, with the new earth strap its got plenty juice to throw the starter gear at the ring gear and get it started. Mines been the same for ages, I just lob it in 4th open the door and put my foot on the floor, push back a few mm and it will fire right up. Link to comment Share on other sites More sharing options...
mean in green Posted May 20, 2010 Author Share Posted May 20, 2010 Well, my car's intermittent "no start" condition has come back to haunt me. Marvellous eh? The only things I now haven't replaced on the starting circuit are the solenoid wire "50" itself and the switch. Chris at GCR suggested the pins or wires into and out of the main engine loom plug or the solenoid wire run from that plug down to the starter as being likely places to continue the search. Anyway as I've little time to investigate myself at the moment I left the car with him. Guess what? It seems as though the new starter motor is the problem - an alignment issue. It can't be much out - it has been working fine for the last eight months after all. Why has it stopped working now though. I mean, it's not like it could just drop "out of alignment" is it? Proof of the pudding - recon Bosch unit hasn't failed to start the car in the fifty plus cranks Chris and I have tried it over the last few days. In addition he had a meter on the solenoid wire when the Cambridge starter was on it - plenty of current there, every reason to start. Just repeated clunks - the bendix hitting the ring gear but not engaging it seems. My ring gear isn't chewed either. To recap, I had this problem with the first starter Cambridge sent me. They happily took that one back to bench test it and pronounced it healthy, then offered me a replacement too. This is the one that's come off the car this week. I'll speak with Cambridge in the morning about. I don't hold out much hope of a refund as it's nine months since I bought the original one, and this replacement is eight months old. The car has probably only done a thousand miles in that time. See what they say about it in the morning but I have a feeling I may be about to acquire a very expensive door stop. Link to comment Share on other sites More sharing options...
mean in green Posted May 21, 2010 Author Share Posted May 21, 2010 All credit to Cambridge Motorsports, they're happy to have it back for further investigations even though it's several months old. Will update again once more is known. Link to comment Share on other sites More sharing options...
Nige Posted May 21, 2010 Share Posted May 21, 2010 Good result in the end, really its in their own best interest to sort it if its an alignment issue as this could affect others who have fitted them to a 915 box. I wonder if they have had this happen before? Link to comment Share on other sites More sharing options...
mean in green Posted May 21, 2010 Author Share Posted May 21, 2010 They say that they sell plenty, both to trade and through their web site and have only had few returns, those being race cars with variations from standard parts. Seems odd to me on a car like a 911, with pretty few changes in the starter / gearbox. If this is an alignment issue it has to either be the throw on the solenoid or the positioning of the ring gear and starter cog, can't be anything else can it? It seems to work on the bench, but then it isn't under load. I might try to temporarily space it back on the studs, but then another part of me thinks I really can't be bothered messing around trying to make it work. Link to comment Share on other sites More sharing options...
heckschleuderer Posted May 21, 2010 Share Posted May 21, 2010 Simon - I feel your pain. I'm on battery number 3, alternator number 3, several earth leads and Northways are fitting starter motor number 2 as we speak. They've had the car for a week now, so I'll wait and see what the final verdict is when I pick it up later. I hope yours will be finally sorted now. Link to comment Share on other sites More sharing options...
mean in green Posted May 21, 2010 Author Share Posted May 21, 2010 Been trying the Bosch recon unit - fires it up every single time. I really like the lightness and sound of the Edge one but what use is it if you can't rely on it? Link to comment Share on other sites More sharing options...
Dr Rock Posted May 21, 2010 Share Posted May 21, 2010 Is there a bush in the gearbox or engine that the starter shaft engages into that could be worn and causing the shaft to bind? Link to comment Share on other sites More sharing options...
mean in green Posted June 10, 2010 Author Share Posted June 10, 2010 Well they say they sell plenty with few returns and they don't get involved with shims either. With the non-start problem reappearing I decided it was time to get professional hands on the job and Chris Sargent's diagnosis was the starter itself. He said "...it bench tests fine but that's not under load as it is on the car. I think it's an alignment issue, your wiring's fine." What I can say is that over the last several weeks the car has seen regular use and the non-start problem hasn't happened once since temporary fitment by Chris of a reconditioned Bosch starter. This seems to me to be conclusive proof that the issue is either the Edge starter itself or some alignment issue with it and my car. Jon at Cambridge has certainly been keen to try and resolve the issue, even though it's nine months since original purchase. My Edge starter arrived back from him this week along with a note: "...The unit has been fully checked and tested. The alignment was correct as per original Porsche starter. We have fully stripped the unit and checked all the internals and replaced the solenoid connections. We have given the unit a small amount of offset to see whether this helps with your meshing issues. The unit has been rebuilt and tested under both cold and warm conditions and all checked out ok." I haven't had the chance to refit it yet, will update again once I have and let you all know the outcome. It's a puzzle, I just don't get it - there's nothing unusual about my car in any sense that would affect the starter. Perhaps I originally had more than one contributing issue, resolved by my other actions? I'm really hoping the Edge unit will work reliably but ONE more "clunk" and non-start moment and it will be coming off the car for good. Link to comment Share on other sites More sharing options...
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