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----- Original Message ----- From: "Jim Adney" <jadney@vwtype3.org> Thanks Jim for all your good ideas. > > But what about the coil? Is 11V enough? Of course it won't affect the carbs > > themselves! > > 11V is fine. I think the coil will work fine down to around 8V, which is about > the lowest that the starter will still crank, on a 12V car. I charged the battery today. It was 12.5V before which is OK but not fully charged. Its now 14.5V. There seems to be a 1V drop to the coil however which has got to have an effect on spark voltage- less current through the coil during dwell. I was searching for ignition lead material today as I'm not overly happy with what I've got- its blue silicon spiral metal wound fancy stuff for RF suppression and I just don't like it. I found some stuff from Van den Hul who usually do high end Hi-Fi cable. Its called HQ-1 and is pure copper with PTFE insulation and is conveniently 7.2mm dia. Don't know the cost yet but hope it isn't the silly price of their hi-fi leads- probably will be though. > > > > Sticking mech advance? Does the shaft snap back easily? > > > > Well it does most of the way, but there is a little area at the end of > > travel where its a bit stiff- will investigate. I did have it aprt and > > cleaned lubed 6mths ago and it all looked fine. > > The bit at the end may just be the backlash in the gears and the drive gear. > The only way to be completely sure is to remove the dist and then twist the > ends. ANY stickyness at this point is cause for concern. I think my dist is OK > You should also check the little ground strap between the 2 halves of the > breaker plate inside your dist. If this is broken/missing then you can have > spark problems. Thats fine as well > > > Overflow hose cracked letting water into the gas tank? > > > > Don't think so- I keep checking it and it always looks fine > > The easy way to check is to top up the tank and look underneath for fuel > leaking out. I've checked regularly and I really don't think I have a problem with this pipe. > If yours is a square, consider temporarily installing a fuel pressure gauge and > take someone for a ride when it's malfunctioning. Have them watch the gauge AND > your timing light, while connecting it to each SP wire in turn. I don't think its the fuel pump as this is the 3rd I've tried in the short time I've had the car and I've always had these problems by varying degree. Here's my new theory- what do you think? This evening I drove home and the engine behaved impeccably. I think I've got it sussed. The difference is that tonight I let it warm up properly. When I first start, the engine now ( thanks to the new properly set up fast idle cams) runs fast. BUT it also misses somewhat. If I blip the throttle too soon, the idle drops and the missing becomes such an issue that the engine stalls. The engine never seems to recover from this and runs badly no matter what (I'm mostly doing short 1/2hr journeys). I guess the plugs foul up and never recovers, or the rings never make a good seal. However, if I leave it for a while the missing gradually recedes and the fast idle increases to a really fast idle- like one of the cylinders catches the gist and starts to work properly. Then if I blip the throttle the idle settles to an OK slightly missy idle and the engine runs fine from then on. So my theory is that one of my cylinders (3 probably) has a problem. I know that 3 has lower compression than the others and I know that the engine has a history of overheating cos of stuck flaps- the head came loose as a result. I'm guessing that its the rings and that at startup I'm getting a lot of blow by. If I let it start up for long enough the heat causes the rings to make a good seal and everythings hunky dory from then on. If I don't give it enough time, they don't get a chance to make a good seal and the thermostat kicks in and they stay poorly sealing for good. If this is true its bad news as it means I really need to drop the engine and change em but I don't know when I'm going to get the chance as this is my daily driver. If it makes any difference, when I had it out last to fix the loose head, I rearranged the rings as all their gaps lined up- maybe that has caused the poorer compression (still 100-110 psi though) BUT there was very little sign of wear on the cylinder - cross hatch still visible the length of the bore. I don't think it can be that bad as when it runs good its delightful and I can't complain about anything. Its just when it runs bad it really runs bad and I know about it every time I fill up. I'l try to let it warm sufficiently every time and see if that makes a difference- now that I've got the carb linkages sorted I expect things to stay pretty constant. I'm going to buy up a lot of spares from GSF as they say they are fazing out aircooled stuff and they have been amazingly cheap so I will buy a set of P&Cs and if I get a chance this summer I think I'll do a top-end re-build. Just for peace of mind ;-) Mark Seaton '73 Fasty London ------------------------------------------------------------------- List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org