Danxs 0 Posted May 6, 2006 (edited) hope this is the right area for this, since having a magnex exhaust on my 309 gti (including manifold) i seem to be getting rather large flames out the back of my car on over run, its only after 5 mins or so of relatively hard driving, but its a bit worrying, i thought they where little, but a mate was following me last night and filmed it, and they are honestly about 3 foot long, permanantly untill i go back onto the power?!?! is this normal, its just been set up on the RR so it shouldn't be overfuelling? any idea's? Edited May 6, 2006 by Danxs Share this post Link to post Share on other sites
Rally Slag 0 Posted May 6, 2006 yep, where can i get a back box like that Share this post Link to post Share on other sites
M3Evo 0 Posted May 6, 2006 Have a vague idea that running very lean can cause what you're describing as the weak mixture misses the spark, passes straight through the engine into the exhaust where it subsequently catches fire. Was happening a lot when we mapped my car so we richened up the higher speed/no load sites and the flames and banging went away Share this post Link to post Share on other sites
Danxs 0 Posted May 6, 2006 ok, the fuelling shoul dbe spot on though, like i said, it was set on the rolling road 2 weeks ago :s, i have a vid on my phone but i cant host it anywhere, its quite ammusing! Share this post Link to post Share on other sites
jonD6B 0 Posted May 6, 2006 The question is did the rolling road set the car up to the manfactures settings or for higher engine output figures. It's definitely not burning the fuel properly so could be mixture or timing. The boy racer side of me says leave it because it looks cool but realistically I'd have a look at setting it up again. Share this post Link to post Share on other sites
richsmells 2 Posted May 6, 2006 I'd get it sorted. Does running lean not create very high temps and melt stuff? Share this post Link to post Share on other sites
Danxs 0 Posted May 7, 2006 after a long chat to a mate last night, he thinks it might be the ECU not shutting the fuel off on overrun as it should, which would explain why i am getting about 15mpg with steady driving! we are going to try a new ECU today. Share this post Link to post Share on other sites
littlemike 0 Posted May 7, 2006 Check that the throttle position switch clicks when the throttle's closed. If it doesn't the ecu won't cut the injectors on the overrun Share this post Link to post Share on other sites
max0 5 Posted May 7, 2006 ok, the fuelling shoul dbe spot on though, like i said, it was set on the rolling road 2 weeks ago :s, i have a vid on my phone but i cant host it anywhere, its quite ammusing! ill host it for you. andrew.j.hey@gmail.com Share this post Link to post Share on other sites
Danxs 0 Posted May 8, 2006 Check that the throttle position switch clicks when the throttle's closed. If it doesn't the ecu won't cut the injectors on the overrun spot on, thats exactly what it was, i cant get the vid onto a pc at the moment as my pc has gone down and i cant find any software to get it off my phone! Share this post Link to post Share on other sites
jonD6B 0 Posted May 8, 2006 Post the vid. anyway even though you've got the problem sorted, these things are always fun to watch. Bluetooth it to a mate who has the ability to download it to their p.c. and then Email it to you. Share this post Link to post Share on other sites
