[s-cars] Flames, good or bad?

[Kirby Smith]

Conceptually, one could get a very rich mixture if the flow at the MAF
was still high when the throttle was mostly shut.  The larger the volume
of plumbing between the MAF and the throttle, the greater throttle
position becomes disconnected from MAF mass flow estimation.  That could
be the cause of the backfire.

kirby


mlp qwest wrote:
> 
> Apologies for the earlier tongue in cheek post about playing with Hap's
> mind, but on a more serious note, who's been following you and for how long
> have they been observing this phenomenon?
> 
> I don't *think* I've been experiencing tail pipe flames, but then again it's
> not a part of the car I can observe very well, particularly at 7,000 rpm,
> it's not usually where my attention or eyes are directed.  I guess I'd have
> heard a back fire - I haven't.  And I suppose if I had, I might have been
> paying more attention to possible flames out the tail pipe.  Are we talking
> a burst of flame out the back that's visible by you from the pilots seat?
> 
> AFAIK Elijah this is a new one for me.  Any other FMIC users out there seen,
> felt, or experienced the same?  Is this on your, or your wife's car?  I
> would think, if anything, you should have a cooler, denser air charge now at
> your intake manifold.  Unless this is totally X***ing up your intake air
> temp sensor in the manifold, you should have more air, not less so if
> anything, I would guess lean vs. rich.  Are you sure all your intake valves
> are seating etc.?  How about your cam timing?  Are you dead nuts sure
> something isn't off a sprocket or two?
> 
> I think a steady diet of this kind of problem would well warrant having the
> car taken in for a leak down and compression test to try to eliminate either
> a bad valve not sealing off an unburnt gas compression stroke, or the cam
> being off somehow.  Unless of course you get a Greek chorus of "Don't worry,
> we've got flames coming out of our tailpipes" from all the other FMIC users
> on the net.
> 
> This just doesn't sound like a good thing to me, Dahlback not.
> 
> Mike
> 
> ~-----Original Message-----
> ~From: s-car On Behalf Of
> ~Elijahallen92 at aol.com
> 
> ~
> ~Hi,
> ~ Ever since my FMIC install at WOT shifting at 7000rpm I get a
> ~backfire/flame. It used to do it sometimes between 1st and 2nd and
> ~once in a while between
> ~2nd and 3rd but now it is after every shift almost every time. Is
> ~this caused
> ~from running to rich? Why would the FMIC make it do it more? Any idea's?
> ~
> ~Elijah
> 
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