my golf has been playing up yet again first it was jumpy /hard to drive when started from cold, i had it on a gas tester and it read 1% cold and 2% hot....i rang stealth and he mentioned a few bits to check and maybe try the wur so i tried another wur..set the c/o just right , checked the sensors in the head blah blah now it fires as normal but almost instantly stalls..it also stalls quite hard rather than fading away cant think of what it can be...maybe thermotime switch not letting cold start valve work long enough?? any ideas
Does it start ok when warm? If so then it's very similar symptoms to mine and I've been scratching my head over it for ages! Apart from temp senders and wiring, check for vacuum leaks in the ducting from airbox to throttle body, overun cut off valve (underneath that ducting), injector seals, dribbling injectors and cold start valve. To be honest from talking to Vince and people on here, the 16v should start without the cold start valve connected at all (mine doesn't though!). Would be very interested to hear anyone else's ideas on this as it's been a pain with my car for ages! Edited by: Stu
yeah its okay when warm..it even ok sometimes when its a sunny afternoon cold start instead of chilly mornings mines a pig to start with the cold start hooked up im wondering if the cold start isnt giving quite enough to cover the overlap from start to running...its that few seconds where its wrong , it fires up well then dies ...also needs to nursed along carefully for afew mins is yours totally consistant or sometimes better?? mine is alright once in a while
No, mine is consistently rubbish at cold starts I'm afraid. When the weather is a bit warmer it will occasionally start on the second try, chug and misfire for about 30 secs and then level out. Mine is the same as your's in that it starts first time, even in freezing weather but then the revs drop straight down and it cuts out. In very cold weather it'll do that about 6 times before it finally chugs info life! Mine has only started doing this all the time since it was tuned and had the WUR done, before that it very occasionally wouldn't go first time but always second time. Pain in the @rse!
stu lets compare notes heres whats been changed /checked over fairly recently on mine lift pump plugs sensors in head cleaned isv newish inj and o rings and intake seals checked and altered flap height in metering head tried a hot c/o of 2 or 2.5 % throttle micro switch tried 2 wur its also been to stealth and he had the gauges on the inj system, he mutered something about it didnt need or couldnt have the wur mod done?? tbh it never ran that good after he set it up my thoughts are that my isv is lazy, i brought a new vdo one say 18 months ago, it buzzed really loud and vibrated alot..now its just a dull buzz even if i clean or lube it...so somethings happened over the time ive had the new isv
Right, on mine: 1. New plugs 2. New injector seals 3. Vince tested injector for dribbling etc - all ok 4. Checked/fixed wiring to temp senders on side of head 5. Tested temp senders with multimeter - all seem ok in that their resistance changes the same amount as engine warms up. 6. Tested wiring to cold start - ok 7. Tested resistance of WUR bi-metallic heater - ok 8. Checked wiring to thermotime switch, WUR etc - all looks ok 9. Cleaned ECU terminals and connectors 10. Cleaned out air box, ducting, throttle body 11. Air flap looks to be positioned corrected in airbox 12. Set up idle as per GVK site with ISV cicuit disconnected, idles fine with no ISV - no vacuum leaks 13. Adjusted WUR back 1/8 turn (he's modded it) at Vince's instruction, helped cold starts slightly but doesn't fix problem 14. Tried starting with CSV disconnected, doesn't help 15. Checked position/operation of throttle microswitch - ok Er... probably a few other things too! Mine hasn't cold started since it was set up at Stealth and the WUR modded, so I'm sorting out a standard WUR to try next. Hope that fixes it but I doubt it, nothing else has! I did take the car back to Stealth and Vince checked it over and said everything was fine and the starting issue must be due to a problem somewhere rather than his tune-up. Good luck - hope you can sort it and give me some ideas for mine! Edited by: Stu
Mine did the exact same thing when I fitted the twin exhaust cams, but I disconnected the cold start valve and now it starts first time every time. I just thought it was giving it too much air/fuel with the hotter inlet cam.
stu...does disconecting the csv make things worse, i tried mine a while back and its a sl*g to start in cool weather does you isv buzz loud or not, when i had the brand new one it ran great and id describe as loud as a loud leccy shaver...now you need your head against it to decide if it buzzes or not another assosiated thing is when dipping the clutch to change gear it will sometimes drop the revs sharply to well below 1000 and almost/sometimes stall, i feel this could be a lazy isv..meaning its not quite quick enough to stabilise the revs when changing gear etc ...and maybe not good enough to sort the cold idle i got my new isv from ebay for 39, im gona try another one if i ever see em again
Yep - disconnecting the csv made it worse to start so it looks like that is doing it's job anyway! My ISV buzzes so you can hear it but not very loud, you can feel it vibrating if you put your hand on it with the ignition on. Can you get a stable idle with the red lead disconnected by the coil (so ISV is not controlling idle)? I can on mine, set it to around 1k rpm that way then reconnected red lead. Revs dropping quickly and nearly stalling sounds like there is a vacuum leak on or near the over-run cut off valve - have a look there. Not sure why your ISV wouldn't buzz as loud as it used to, is the wiring to it ok, not a dodgy connection somewhere?
yeah mine idles fine without the red black wire, mine seems to prefer a slightly higher idle than the 950 the manuals suggest im going to fit new terminals to the red/blk connector for the hell of it, but the revs change when i disconect it ,so i spose it works funny you say about the over run cit off, stealth broke the vac connector off it and ive glues it on, maybe a used one would suit at the weekend i wire brushed the head sensors , and today it was fine..im going to get some quality spades and make sure theyre 100% tight fit .
Hmmm... so it started alright today then? Sounds like a temp sender connection problem then after all? I'm going to have to have a good look at mine, clean them up (again), check and repair any wiring and take it from there. I believe it's the blue/white wire that goes to the ECU isn't it that would cause the problem we are experiencing? Report back with any updates!
thing is they werent filthy, i keep my engine clean..i just wire brushed em for the hell of it really i also have the later mushroom head sensors..not 100% sure they should have spade connectors on em may ring vw and ask it does seem a little bit connected to weather conditions..like it stalls on chilly morings, but after work it just about runs sometimes....always drives away on the 2nd start up although you need to nurse it along
I would think that after work the car might still be a little bit warm so starts easier. Mine is a pig in the morning requiring several starts and a period of 'chugging' before it's driveable. After work (say 8 hrs of being left standing) it'll go first or second time but still chug for a while, not too bad though. Those senders tell the ECU whether to cold start or not depending on the temp of the coolant as far as I know so do seem connected to the problem. Going to check all my connections and clean them up, even though like yours mine is pretty clean anyway. After that, might look at replacing senders and wiring. Edited by: Stu
stu..i was going to post up tonight that it is much better..BUT i got home and thought id clean up the sensors to mint condition with a dremel, got em minty clean and now its running worse didnt touch anything else...sounds like they could be a prob do you know if it matters which wire goes on what sensor..im thinking it dont matter
the sensors on the side of the head are all same part numbers m8 so dosnt matter which wire goes where,as long as the right wires are there in the first place! im pretty sure if one of em is unplugged the car wont tickover? one to the ecu i think. ps:did you ever run the car with the isv disconnected? may have sucked in a bit of crap? neil. Edited by: riley
