Hello, I have a 1989 GTI 16v Match I rebuilt the car, and I restarted recently* It runs well, starts well, but idle is not clean, it looks it has mis fire, and make vibration I timed ignition to 6° BTDC Some observation: -no effect when unplug the red/black wire near coil -no effect when unplug vacum hose to ignition module I tried to search where this red/black wire goes, but I have problem with documentation Mine is as this one : https://clubgti.com/forums/index.ph...-scans-corrado-golf-2-19-1g-passat-31.277245/ on the CE1 "wiring diagram for ignition system 1.8 16v", the wire stops to n°37, but can't find continuation of n°37 thank you for help *https://golfgti16smatch.wordpress.com/
the red/black wire at the coil goes to the isv module pin 17/1 '37' on the diagram refers to the circuit track number, these are written along the bottom of the diagrams left to right. so in this case 2 pictures down from the one you're looking at, up to the ISV module which is hidden behind the centre console check the black wire to the module has ignition live, and the brown/white should be earthed to the cylinder head
All right, I was looking for another '37' label ok, I will remove the center console, and check that for information, when unplug ISV with engine cold, engine stalls, when engine hot: engine barely runs
Hi John, thank you for your answer I worked on the car ISV module brown wire wired to cylinder head=> OK black wire live with ignition =>OK then, I tested all wires from this module (I rebuilt the loom, you can see on the link I posted ) Everything OK, expect the red/black wire: wrong connection at the 6 pins connector behind fuse box=> should be the main problem, now corrected while I was at it, I tested wiring of other components the trottle => switching OK pressure change=> wiring OK and vaccum with mouth OK ISV wiring OK cold start injection wiring OK I tuned again the timing, and when unplug the ref/black wire, there is a rpm change Now, there are still some misfire, but less Also, I tested the cold start injection dynamicaly: engine running: injector not connected, engine hot, pressure change shorted => no voltage at injector connection. After some readings, it seems this would happen only when engine cold, can you confirm? Also noticed vacum circuit is a bit leacky on the pressure drop, and pressure change sensor side, When engine running and unplug the vacuum from ignition control unit, no effect (everything else connected) to have nearly no mis fire, I have to set reachness to 1.8, and idle screw is at the lowest position at 1000rpm+. I think it is not normal
the 5th injector thermoswitch will cut the path to ground once the engine is warm and/or the engine has been cranking for a long time so if you were probing for voltage across the 5th injector 2 pin plug this would be correct yes with your high idle, if everything else is confirmed good possibly you have a leak at the air shrouded injector system, if you fitted new injectors without top hats for example. you can test this by pinching the vacuum tube from the breather pipe to the inlet/5th injector housing
RJ all indicators are an air leak/s and I agree but a really good afternoon spent can be rewarding in restoring air control, have had this so many times and recently with my ABF conversion ,transplanted kr CIS on to it and found my problems with the old KR came with that ...makes sense. Replaced a lot of bad vacuum/air hoses in this process and leaking air mixture screw seal and bingo with a quick start smooth cold start a great warm idle,the old kr wasn't great but the engine was about to die and terminated on the roadway just before I got up the driveway to my new place.
yes, I have shrouded injectors I pinched this hose, engine, stalled I sprayed many aeas in the engine bay with brake cleaner and I couldn't hear rpm increase the fifh injector works dynamically (either shorting the valve + increae throttle) or throlleling only, even engine hot after some minutes idling, when is the thermo-calo contact supposed to switch ? measuring my rpm with strobo lamp, I have 970rpm (still with idle screw at minimum and 1.8% CO) I sprayed all air circuit with brake cleaner, and I couldn't hear rpm change, also at inlet, and no more, probably idle stabilisation working (I am more used to diesel these years) sorry, I can't make picture works, they display when I edit the post, but needs click on final version
the hose I mention to pinch is the thinner one which is connected to the block breather hose on the front of the engine block, this is what feeds the air shrouding system. but so long as you have the right injectors and renewed the plastic injector inserts along with the square profile seal thaty goes between the inert and the inlet that side of things should all be ok with the images the problem is some image sites dont like the way we have to re-host the images so they work on here properly, or just wont allow hot linking. Once you have a few posts you can upload images directly
I think it is the good one, but you can click the "wrong" icon of my picture, it actually works In case of a leak, the engine should rev faster with spraying it with flammable, right?
yep, its just the hot linking direct which falls over for some hosts if theres an air leak spraying wd40 or whatever will make the idle change yes. if theres a leak past the air shrouding system thats harder to track down as its just pulling too much air in via the breather so spraying WD over the injectors wont show you that but yeah, if you've redone the inserts and injector seals etc no need to worry about the air shrouding
the air shrouding system allows a small amount of air to flow past the tips of the injectors to improve atomisation and so ecomomy etc. what people did a while back was buy new mercedes brass injectors because they were dirt cheap. these work fine but dont have the 'top hats' and so gives you a large air leak past the injectors through the air shrouding system, the simple fix here was to just block it off, no problem. in your case, this isn't a worry as you've rebuilt everything and used the right injectors. heres the page from the SSP handy if you can read German or can be bothered to type it all into google translate
