Sounds like it may be just OK. That cam is adjustable, might be worth rotating it clockwise a touch (screw in slotted hole); that should make sure the stop clears the edge when the waxstat's done all the extending it can.
Sweet... refitted it all. Seems spot on now. Not too sure what's done it.....maybe shock therapy for the waxstat, getting it moving in and out a few times? And getting loads of full movement for all the mechanisms, free everything up. Will see how it goes and if need be ill have to take it off and have another look at the cam. Cheers pal.
Still struggles on startup from dead cold but after a few seconds of (not over) revving seems good except idle speed. Idle revs from cold are a bit low then once warm/hot goes to around 1400. This is with the 3-4PU all the way in still. I can bring the revs down by pulling the little screw (that connects with the 3PU plunger) out more (so the lever goes closer to the plunger) but then this affects the startup idle (revs too low). Should I think about rotating the cam so the 3PU can take over sooner?
Right, now that you have a rev counter, I think you can sort this. In Haynes etc. there is a "Fast idle speed" figure of 3000rpm. Now in normal use, this never happens, but it's quite easy to check this figure, which corresponds to "the revs that you should see on a fully warmed-up engine if the 3-point unit plunger is at full extension." How you get the 3PU plunger to full extension on a warmed-up (running) engine is by simply disconnecting the lower of the two vac hoses that go to it. Depending on what your rev counter says with this vac hose off, you can adjust the little screw-through-the-plate until you do see 3000rpm in this condition. I'm pretty certain that the 13mm nut on the back of the 3PU doesn't affect its fully-extended dimension. Top tip for you when experimenting with this: Don't try to switch off the engine with the key while the engine is racing away at 3000-ish revs with the throttle held open by the 3PU. It will run-on like a bee-atch in a very uneven, alarming way. Just re-connect the vac hose that you've pulled off, and the idle will drop down to normal levels again, and will stop normally when the key is turned off. Once you've got this "fast idle speed" correct, that should mean you can adjust the 13mm nut on the back of the 3PU to get the 'normal' idle speed right. You should then find that it will start OK whatever the temperature, and idle at reasonable speed during and after warm-up. (Provided that the waxstat does 'release control' correctly after a few minutes). You're nearly there fella.
Got it up to temp. Long drive so all 'heatsoaked in' IYKWIM. Idles steady and drives well but idles at 1400, 3PU all in. did the fast idle test, 3200. sorted this to 3000. refitted everything, good steady idle of 1k. I'll recheck the part throttle channel heater, coz yesterday it was giving 0.7V. And get the manifold hedgehog and the autochoke heater working coz i dont think they are getting voltage (when cold), which will be affecting the startup. When ALL the electrics are on, hazards, stereo, blower etc... I get mad fan belt squeel, should i just tighten it a bit more?
If you can't remember or don't know when the aux. belt was last changed, I'd be tempted to throw a new one at it. If you overtighten an old, worn belt, there's a real danger of screwing up bearings in alternator/water pump. I can't remember the way to check the tension, but Haynes'll tell you or some other kind reader of this. If it is just looser than it should be, and is reasonably recent, just tighten it a tad. Progress sounds good on the carb, well done. Get those electrics all diagnosed/fixed and you'll be in business, I reckon.
Was me that last changed it around November as it went about 100m from my house, luckily enough. Think the tension test is that you can twist just enough to 90' along it's axis without too much force. or it might be that you can push it down 5mm with moderate force... I'll have another tighten and go from there, It's a new belt. Yeah seems spot on with the carb now (HOT) I'll sort these other warmup items. The fact that they are not getting 12v, is this most likely to be a break in the wire? Can I get the F'Box location from RubJ's Fusebox FAQ easily enough to check for broken wiring?
I'm a bit tired to think about this clearly just now (big night last night). IIRC there is an error ( ) in the Fusebox FAQ with respect to one of these connections, which he can't edit/correct for some strange (forum) reason. I'll have a look at the Haynes wiring diags for you in the morning if you want. Double-check that the thermoswitches on the coolant flange both work as a starting point, should both conduct (zero Ohms) when cold. Part-throttle heater is on all the time ignition's on, no thermoswitch.
Yeah I cant go back ad edit any of my posts which means te faq on this forum is pretty out of date compared to elsewhere! I'm planning to start a fresh thread with the latest version soon. I still have your pm on the error in question:
okay, All this is dead cold engine 4'C. TTV, part throttle channel heater and idle over run valve all get 12.14V on ignition. Autochoke does not have 12V. Connections at the back of the FBox seem clean and good. Part throttle channel heater doesn't have full continuity, when testing for this with a scale of, I think, 2000, both wires from the part throttle channel heater show 400 ish when touched to carb. Inlet manifold heater; has continuity to earth and also through both ends of the RED/WHT feed wire to the FBox. However, there is no live feed to it from the FBox connection 'N' on ignition. Autochoke now has good earth to the cylinder head. The wire that feeds it has continuity back to the thermoswitch. Both thermoswitches do not pass current when cold.
Figures why I aint got 12v then. Both of mine didn't pass current. Are they connected at the box anywhere? Could it be a fuse/relay? Or are they both kaput?
Can you confirm that you're checking the thermoswitches like this: This one works at 0.3Ω (same reading when you short the probes together, so it's really 0.0), so you can have it if you want it, I'm guessing yours are the clip-in type not the screw in type?
Yeap clip in types. Yeah, that's how I'm testing it. When I touch the probes together it buzzes (zero resistance) When I touch them like on the picture it just stays showing 1 (which shows open circuit).
just read post #74! Don't know what I was on about. Think I will bridge these two switches for the mo so they show closed circuits and provide 12v to inlet mani heater and auto choke. The only travelling i'm doing until Friday are 7 miles trips to and from work and it's going to be cold engine starts everytime. Where can I buy these? PS Pete, i'll have that off you. I'll PM ya. ta
Send me your preferred delivery address, and I'll pop it in the post today. VW still sell 'em, not too expensive, but try the red one I've got, and just leave the grey one bridged for now.
Everythings getting 12V now (bridged thermoswitches for now). Starts up very well but idles at 400 (only for a minute or so) unless I give it a few revs from dead cold. Doesn't ice up. Revs well and pulls okay. Warming up and HOT idle is at 1k. Only little problem there might be is the throttle response seems a bit sluggish, no flat spots or anything though. Will have to look at the throttle clip next time I can be a***d, maybe it's a touch loose. Will get the thermoswich in too. Also need to take off the part channel throttle heater coz I didn't get a good earth last time I checked, but the screw aint at it's best and is a bit naffed up.
Next time you start it up from dead cold, open the bonnet first, lift off the whole airbox, and watch both the plunger of the 3PU, and the choke flap. Either the 3PU isn't staying at full extension for long enough - should be around 5 seconds, ballpark, in this sort of weather - or, the choke flap isn't opening as it should with the help of the pulldown unit. Should be at the first stage (2.8mm on an EZ manual) by the time you get round to look, and 5.6mm within a second or two after. Of course, you won't be able to do this check if it won't idle without accelerator pedal help from cold...
