Hey guys, After a prolonged absence from VW's i've recently picked up a red 8v as a rolling project (initially until it goes for paint next year). So far i've fixed a load of wiring issues. Mainly indicators not working that sort of thing. I've also changed the ignition and door keys so they all match now. Heres a couple of progress pics, including swapping the little tumblers round in the boot lock to get the key to work in it. Getting the steering lock off was hard work until I bought a bearing puller. Amazing what the right tool can do for your sanity. Any midlands based members about? I'm 2 minutes away from Long Marston Airfield where GTI international used to be held. The old steering lock had already been drilled at some point in the past Changing boot lock tumblers over I've also noticed the accelerator is incredibly stiff, and then tonight when I was looking under the bonnet found this little item all squashed up where the accelerator cable is connected. Can anybody tell me where it came from? Today when i've been driving in the hot weather it was idling at like 2k not the normal 9-1000 it usually does (although when cold it does hunt up and down for a while when stationary). I've ordered new vac pipes and a new blue temp sender as well to eliminate all the other possibilities. Anyway once that's all sorted it's then on to sort the sloppy gear shift out, sort the brakes, new suspension, wheels and tires (ATS classics i'm thinking).
So new vac pipe arrived from GSF fitted that today Old vac pipe, seemed in good nick other than a couple of frayed/split ends but replaced it anyway Also replaced blue temp sender Also my new key blank arrived so I can get a spare cut. All of these are fairly minor at the moment but i'm gradually just chipping away the niggly little jobs before I start tackling the major stuff. The Golf has had an erratic idle from day 1 and I had hoped that changing the blue temp sender and the vac pipes would resolve it, but no. So to the experts - any advice? I know that RJ has a tuning guide for the digi but I don't want to start playing with the timing etc yet as I want to do a cambelt/waterpump change before and that's a few weeks away yet. Is the ISV prone to failure/ problems? I'm not a mechanic by any stretch of the imagination so trying to think of potential causes is not my strong point. The idle tends to hunt between 6-1300rpm at idle, when warm. From cold its pretty solid, starts on the button and will idle well. When the needle on the rev counter is going up and down you can add a tiny bit pressure to the accelerator and then slowly release it and the idle will stabilise at about 900 rpm. So i'm really not sure where to go next.
Here's how she looks at the moment, decided to change the thermostat and coolant to see if that helps with the idle issue. Seems to be running really rich at the moment so I wonder if the thermostat has gone or even if there is one there at all. I guess i'll just have to work my way through all the possible things it could be. Also I keep seeing another red mk2 going up and down the Camden road in Stratford Upon Avon, Anyone on here?
I had exactly the same problem with idle as you. I also changed the vac lines, even though the others looked good, to no avail. I did, however, find a 'cap' or 'bung' missing from this area..... And once re-plugged, the idle evened right out Putting my finger over the hole and the pressure would suck on my finger. Kind of a hissing noise that then quietens. I hope that helps, Rich.
Thanks Rich, i'll have a look into that as well (i'll add it to the ever-expanding list of jobs) Don't suppose you have a close up of the area do you? I've no idea what i'm supposed to be looking for?
Hi, sorry for the prolonged reply! I don't have a close up as the engine has now gone but I managed to Google search for similar which should help. I'm 99.9% sure it was on the brake booster pipe....or looking at the below photo....the top circled 'cap' I do hope this is of some help. Rich.
my guide isnt just for tuning, there is a lengthy section before you even get to that side of things covering a load of different checks you can perform on the system. fiddling with idle, co and ignition timing is the last thing you do once you are 100% sure everything else is tip top if the idle is uneven most common cause is either the idle switch isnt making contact, or the wiring to the switch behind the throttle body is broken. the isv can fail but its usually pretty reliable, if its very dirty a clean can help. make sure its buzzing/vibrating with the ignition on. but yeah, read my guide all of this is covered and more
Thank you, so far i've removed and cleaned the ISV, changed the vac pipes (is there a vac pipe that runs to the MFA as well?) and I am in the process of changing the thermostat (although so far i've been sent 2 coolant pumps which have both had cracks in them which is slowing me down) because it was running really rich as well as idling erratically. Oh and changed the blue temp sensor as well. Hopefully when I finally get the new pump fitted I can run it up and see if that erratic idle is still there. Hopefully i'm slowly eliminating all the potential causes one by one...
It's coming up to 20 years since I tinkered with a digi mk2, I'm sure there was a brass idle bypass screw in the throttle body usually full of breather crud and gunk? Take it out, clean it, clean the oriface, clean the throttle plate / body itself, make sure the little rubber seal is intact on the brass screw. Refit all the way in then back off two turns?
Thank you, i'll give it go. Just waiting to refit my coolant pump with new thermostat after being sent two, brand new units, both with cracks in...
Also replaced blue temp sender [/QUOTE] I had lots of issue with these sensors, I ended up buying a few to keep them in the glove box. Car looks nice and good luck with the rest of the project.
I had lots of issue with these sensors, I ended up buying a few to keep them in the glove box. Car looks nice and good luck with the rest of the project.[/QUOTE] Funny you should say that, got the car back together today flushed the coolant system through, new header tank, new power steering pump, runs like a dream... except rev it too hard and we hit the erratic idle again. The rest of the time the engine is smooth as anything. I reckon it might be the new temp sender I fitted a while back. Either way i've ordered another new one, this time direct from VW which will get here Wednesday. That's a long winded way of saying I agree with you.
on the vacuum line side there is one on the front of the throttle closest to the rubber boot, plus another round the back which should be blocked. the one on the front closest to the inlet manifold is for the FPR and warm air feed in the airbox, you can bin off the line to the airbox if you want it doesn't do anything really in uk climates. then for the mfa this one is found on one of the brake servo hose nipples, theres a picture of it further up in the thread its the one with the 2 green nipple blanks circled. one of these should be blocked, the other feeds the MFA. theres also a big yellow cap too, this can crack or get worn thru so make sure thats ok too.
So new coolant pump in and everything up and running properly. Also new power steering pump fitted, along with new expansion tank and cap. Looks much better. Coolant pump did not want to give up its pulley without a fight Obligatory 'giving it the finger' pose. And the thermostat was in two pieces... Yet another brand new temp sender on order, this time direct from VW so maybe that will sort the erratic idle out
thats the ones aye, looks like the yellow cap has previously failed and been replaced with the good old 'hose with a bolt in it'
Okay, so tried a new blue temp sender today this time direct from VW as it was the last thing I changed before the erratic idle kicked in. Could you explain how I can check the throttle switch wiring (I think you said that was a common issue?) with my multimeter, I mean what sort of indicators will I get that it isn't working or is faulty? Stealth are only down the road from me but i'm determined to figure this bloody fault out if it kills me. I've done the checks on your tuning guide and replaced the vac pipes (not the MFA one but would that factor in?) and cleaned out the ISV. I'm not convinced the tuning guide would affect things much as it runs absolutely perfect at idle and during daily use. Then of course when you come to a stop the erratic idle comes back but can be made to idle smoothly by gently accelerating up to just over 1k revs and slowly letting of the accelerator again. Or maybe I just don't understand these engines very well....
By the way just to add insult to injury the piece of hose that was used to plug one of the holes has the bloody Ford logo on it.
