BenB
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| posted on 23/1/07 at 03:20 PM |
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Exhaust fizzing / backfiring on switch off / carbs- don't you just love them!!
Any ideas why my car is making funny noises ?
I suspect its running rich.
Certainly my MPG is not that good but then I am hooning round @ 8k!! (blimey it's cold!!!). No screen, no goggles, no nothing @ 70mph!! Popsicle
time...
If I accelerate then back off (or at least stabilise the rpm) I get a funky fizzing noise from the cans. And the other day when I switched the engine
off (I'd been idling for a while) I got a rather funky backfire out of the exhaust. From my Colortune experiments I know the idle mix is pretty
good but I think the CV springs need to be a bit stronger- I'm get a serious amount of enrichment on load....
I'm planning on doing the EFi pretty soon but wanted to check if those symptoms sound like rich running.... might be tempted to do some
rejetting in the meantime..
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NS Dev
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| posted on 23/1/07 at 03:27 PM |
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probably an air leak on the collectors?
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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macnab
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| posted on 23/1/07 at 03:29 PM |
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I’d leave it as I love backfires, especially at gas stations!
Scares the sh%t out of folk he he 
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BenB
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| posted on 23/1/07 at 03:33 PM |
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Would a leak at the interface between the can and the headers do it? I'm pretty sure the headers are well seated onto the engine and I used new
gaskets etc, bolted up tight etc....
but where the two headers join into one big tube which goes into the can I haven't used any sealant (just a big exhaust clamp)- not sure if an
air leak would cause the noises (presumably there shouldn't be that much petrol in there to begin with!!!)...
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graememk
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| posted on 23/1/07 at 04:54 PM |
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your lucky i get flames on over run on mine,
stand well clear lol
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BenB
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| posted on 23/1/07 at 04:58 PM |
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Haven't had any flames yet!! Once saw someone tuning an old Xflow engine with the air filter top off. Leant over to tune it and got slightly
singed (how do you spell that!!) by the resulting flame that shot out of the inlet mid-tune-up... Luckily they were fine (just a little
suprised!!)....
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