DamirGTI 344 Posted June 23, 2007 Hello ! Please boys i need some help : I have some misfire problems and this happens only when the engine is hot (at operating temp. 80-85C), when i start the engine cold its ok. . It starts to misfire badly and eventually car shuts off completely . So i must wait for a few min. and then i can start again and rush fast back at home until it starts to misfire again . Anyway i lift up the bonnet and i can hear clicking and see spark jumping from main coil HT lead on brake servo pipe which was near that HT lead again this starts to happens when engine reach operating temp. So i try with new leads , dizzy cap , coil but with no luck it's still doing that what can be wrong ? ignition module maybe ? something else ? Here you can see from where the spark is jumping out (this isn't the picture from my car but its the same as mine) : Thanks Damir Share this post Link to post Share on other sites
Richie-Van-GTi 74 2 Cars Posted June 23, 2007 Id double check the lead for starters and then be tempted to open up the sheath over the wiring loom and check nothings exposed inside, although I doubt anything in there will be carrying enough curreent to arc over that far. Ignition amp is the most likely though as its heat related. Ive got 2 known good genuine pug ones if you get stuck. Check my for sale post. Share this post Link to post Share on other sites
DamirGTI 344 Posted June 23, 2007 ok. i will try with another module tomorow I have some spare modules in my garage , but thanks anyway ! cheers Damir Share this post Link to post Share on other sites
t16ryan 1 Posted June 23, 2007 Have you tried another coil ? Share this post Link to post Share on other sites
DamirGTI 344 Posted June 23, 2007 Hi ! Yes i did try with another coil and it's good spare one(first i was thinking that it must be coil because it misfire when hot just like the faulty coil..)but it's the same it's not a coil . cheers Damir Share this post Link to post Share on other sites
DamirGTI 344 Posted June 24, 2007 Hi ! Fixed , and yes the unlucky winner is the ignition module I've found one loosen bolt on module and theres no thermal paste on the module surface at the back , seems like all paste was dried out .. Anyway i fit another spare Bosch module and it's fine now no more misfiring and current leaking .. Some pics : http://i27.photobucket.com/albums/c151/Pie...is/IMG_5350.jpg http://i27.photobucket.com/albums/c151/Pie...is/IMG_5351.jpg http://i27.photobucket.com/albums/c151/Pie...is/IMG_5357.jpg http://i27.photobucket.com/albums/c151/Pie...is/IMG_5361.jpg Cheers Damir Share this post Link to post Share on other sites
C_W 3 1 Cars Posted June 24, 2007 Glad it's sorted, I would have suggested the rotor arm if you're getting arcing like that and HT leads are ok. Share this post Link to post Share on other sites
DamirGTI 344 Posted June 24, 2007 Hi ! Yes i was thinking to change the rotor arm next , if this spare module changing didn't work in the first place .. I will try again with this "Marelli" module but with new thermal paste and tight the bolts , just wish to see maybe it's good just needs new paste behind and must tight these two bolts firmly Anyway it was a bit strange symptoms cheers Damir Share this post Link to post Share on other sites
proaxis2 0 Posted June 25, 2007 Hi ! Yes i was thinking to change the rotor arm next , if this spare module changing didn't work in the first place .. I will try again with this "Marelli" module but with new thermal paste and tight the bolts , just wish to see maybe it's good just needs new paste behind and must tight these two bolts firmly Anyway it was a bit strange symptoms cheers Damir I've just had similar issues, I replaced the Ignition module with a known 2nd hand one and it fixed all the problems until the engine was up to temp and it started hesitating when you feathered the throttle. If you feathered for long enough it would then cut out and have to wait a minute or so before it would start again. I presume this is because I didn't put any thermal paste on and the module is over heating? Have I screwed the module by letting it overheat and does that thermal paste really do that much? Cheers Adam Share this post Link to post Share on other sites
lee-bg 0 Posted June 25, 2007 (edited) You havent 'fried' computer CPU thats why you ask if thermal paste is needed ))) yes it does make difference, because it helps move the heat over to the metal plate which acts like 'radiator cooler'. So best is to get some computer CPU paste and put it on between the module and metal. I doubt module is fried, but you never know. Edited June 25, 2007 by lee-bg Share this post Link to post Share on other sites
Richie-Van-GTi 74 2 Cars Posted June 25, 2007 if you can still start the car when it cools down then the module is fine. Share this post Link to post Share on other sites
DamirGTI 344 Posted June 25, 2007 Hi ! Yes i can start the car after he cools down , must be because that thermal paste was dried out.. or because of the loosen bolt cheers Damir Share this post Link to post Share on other sites
