My 2.0 Pinto is 'popping' on over run, or when i lift my foot off the accelerator. Its not backfiring or spitting back under load, is there a remedy for this...i have been told its cos the exhaust is so short it sucks air in on over run (Its a Tiger avon) Thanks
I would check ign timing first!
Cheers
Rich
are leak in exhaust system??
Id leave it though sounds nice!!
might be running weak mine used to do this till i set the carbs up
Its just simply running lean on the overrun nothing more, nothing less.
Basically fuel is cut on the overrun which means it never fully burns in the combustion chamber and a lot gets pushed into the exhaust. Eventually
enough builds up to ignite from the hot exhaust and it pops.
Too much can be annoying, a little is nice though.
If you have mappable injection you can adjust the effect quite easily from no popping, a little burble up to spitting flames and all sorts 
Thanks. I aint got mappable injection, the cars on Twin 40DHLA's with electronic dizzy, it is popping a bit excessive so if i can cut it down a bit would be ggod,i might have a tinker, thinking about megajolt over the winter can it be reduced with a suitable map for this system?
dont bother, i've got a 4age with twin dellorto and megajolt and its also popping and banging all over the place, sounds more like a WRC rallycar
with ALS (anti lag system)
last time i went to the petrol station i switched off the engine and then a loud bang, people jumped
quote:
Originally posted by Werner Van Loock
last time i went to the petrol station i switched off the engine and then a loud bang, people jumped
You might still want to check for air leaks in the exhaust system though 
My crossflow (twin dcoe's, electronic dizzy) pops and bangs like that whenever there's an air leak in the upstream end. Loose manifold nut,
delaminated gasket, loose fit between sections or a cracked weld for example.
Hmm, I love a bit of low banging in the exhaust..
I have slightly better/worse situation whereby coming off the throttle to change up when accelerating, the thing backfires when I push the pedal again
then takes off!.
Worth checking your not running seriously lean though, that's how you hole a piston.
mine pops a little on overrun i know its setup spot on as it was done on a proper rolling road. if your mpg is ok and its pulling fine then i wouldn't fiddle with it. best bet is to take it to a rr and just pay to have it checked. shouldn't cost too much and they may be able to eek a bit more out of it.
i want my car to pop, just a little to put a huge grin on my face. My car has been meticulously set up though so it just sounds nice and goes like stink!