MY CAR SHOOTS FLAMES!!!!!!

95cobra50

New Member
Feb 19, 2004
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ok so about 30 of us are going on a cruise and i'm getting on the high way and i row through the gears and cruise for a bit. A lil while later were sitting in a parking lot and a guy in a svt focus comes up to me and is telling me how my car was shooting big ass flames out the back when i shifted 2-3 and 3-4. So i have a few problems flames, detonation after 4000rpm, running lean, and a back fire. I think the back fite is from not having the tube running from my smog pump to my bung on the h pipe though. Any help before i burn something up?
 
95cobra50 said:
So i have a few problems flames, detonation after 4000rpm, running lean, and a back fire.


Back fires out the exhuast are caused from running to rich. If your running lean then your not getting enough fuel and there would not be any extra fuel pudding up and back fireing.
 
Is the bung on the H pipe sealed off or open? Everyone has the detonation and a cheap fix is pull the spout, set timing at 24 degrees and leave it out and you will get rid of the ping until you can afford to do other things like change all you sensors.
 
Striped5.0 said:
Back fires out the exhuast are caused from running to rich. If your running lean then your not getting enough fuel and there would not be any extra fuel pudding up and back fireing.
well the dyno showed that i have about a 15:1 a/f right now. So I dont know what its doing. Last time i checked the fuel pressure it was 42psi. I just got a new IAT sensor about a week or so ago. How do i checks what the resistance of my 02's is? The bung is open but im going to take off my h pipe and weild it shut either today or tomorrow. Is ther a way to tell if my 02's are bad or not. If i take out the spout and run that much timming will my computer see whats going on after a while and fix it?
 
95cobra50 said:
well the dyno showed that i have about a 15:1 a/f right now. So I dont know what its doing. Last time i checked the fuel pressure it was 42psi. I just got a new IAT sensor about a week or so ago. How do i checks what the resistance of my 02's is? The bung is open but im going to take off my h pipe and weild it shut either today or tomorrow. Is ther a way to tell if my 02's are bad or not. If i take out the spout and run that much timming will my computer see whats going on after a while and fix it?
when you pull the spout, you are taking away the computer's ability to trim timing. so no, the puter wont do anything.

your open bung hole is probably allow a rich condition to oxidize when it reaches the open hole. quite a few cars will shoot flames if the cat and further plumbing are removed.

ill add that you should not see the same stoichiometry across the board - so the number you gave is not really relevant - or was that the leanest it ever got?
my ramblings. good luck.
 
they dyno sheet would only print off 18:1 a/f and mine was above that flat lined so about 20:1 or so is the leanest its been. I got it tuned but they didnt do a very good job but its not that high anymore so thats better than what i started with.
 
i might have someone dial in more injector pulse-width, etc - you dont want to run lean while flogging it. the leanness could be causing more chamber temp spikes, which causes more detonation, which causes higher temps, which causes more detonation (LOL - vicious circle).

good luck with it. a lap top and some software might be a good investment.
 
95cobra50 said:
would haveing my EGR capped be messing up my temp? I heard that it can make it rise a lot
what did you do with it exactly? the EGR cools the chambers when spent gasses are being introduced (light throttle and cruise). the puter knows to expect this and advances timing. if you remove the spent gasses w/o telling the puter (read burn a chip, etc), you will have hotter chambers and way too much timing.
 
all I did was put natural gas caps on over the holes because the guys who installed my LT's broke the in half and didn't even close their holes all the way so i was having a leak.
 
keep what i said in the back of your mind if you start pinging a bunch. you guys seem to ping enough w/o adding other ways for it to happen. :)