Running Rich

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ladenblowfish

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I know this is a stupid question guys but if the fuel pump is going bad would that cause the car to run rich or lean? My 93 is running rich. It smells like gas at idle. Also its turning my tailpipes black. Fuel pressure is 32-35 psi at idle and 35-38 psi at wot. All sensors have been changed including both o2s, cleaned maf, 764s, 9mm wires, coils, etc. At wot, it feels like it kicks back at top end. Thats why I'm suspecting fuel pressure.:confused:
 
If you are getting proper fuel pressure I would doubt that it is the problem.

You also really can't say that your car is running rich based on a smell. If you had a wideband you could say definitively what your a/f ratio is. I would say that if the car still runs good and it has changed smells the cats would be more to blame.
 
I was thinking it was running rich because my pipes are black after a couple days of cleaning them. It really started to do that after I removed the air box. It still runs the same either way.
 
Whats the correct way to check fuel pressure at wot? I read you could unplug vac line from fuel reg and get a reading simulating wot. Correct?
 
My friend has a turbo Grand Prix and at idle he had 42 psi of fuel pressure, and at wot sitting in place it would go to 38 psi... but at wot under load it would drop to 10 psi and the car wouldn't go over 3k...
 
kustomizingkid said:
You also really can't say that your car is running rich based on a smell. If you had a wideband you could say definitively what your a/f ratio is. I would say that if the car still runs good and it has changed smells the cats would be more to blame.
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a wideband is useless unless you have something to actually tune the car with.
 
bryantaylor said:
a wideband is useless unless you have something to actually tune the car with.
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He made the comment that his car was running rich, or has a rich a/f ratio...


My point is that he has no factual evidence to back that claim up, a wide band could give him a real a/f reading, and thus it could be determined whether or not the car truly is running rich.
 
Yes sir! Fuel pressure at wot drops to 28-30 psi.:eek: Thats my problem with it kicking back at wot. But would that also be the reason for my sooty pipes also?
 
I'm thinking of going with the 255lph pump from supercoupe. Is there a better place to get it from?
 
kustomizingkid said:
He made the comment that his car was running rich, or has a rich a/f ratio...


My point is that he has no factual evidence to back that claim up, a wide band could give him a real a/f reading, and thus it could be determined whether or not the car truly is running rich.
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so could pulling a plug, and that doesn't cost $300+
 
bryantaylor said:
so could pulling a plug, and that doesn't cost $300+
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If you want to :q:q:q:qing argue with me go ahead, it was an arbitrary statement about the falseness of using the smell of the exhaust to determine a/f ratio. My only real point was that if he wanted to truly, factually know his a/f ratio a wide band is really the only choice lol....
 
kustomizingkid said:
If you want to :q:q:q:qing argue with me go ahead, it was an arbitrary statement about the falseness of using the smell of the exhaust to determine a/f ratio. My only real point was that if he wanted to truly, factually know his a/f ratio a wide band is really the only choice lol....
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so the smell of unburt fuel out of the exhaust is not a sign of running rich? or pulling a plug? you HAVE to have a wideband to know your rich? interesting
 
pull a plug...easy as that...if you have a wideband why not...fuel smell could be injec o-ring gone...anysign of wetness around injectors?...smell like rotten eggs at high rpm? could be a cat...
 
bryantaylor said:
so the smell of unburt fuel out of the exhaust is not a sign of running rich? or pulling a plug? you HAVE to have a wideband to know your rich? interesting
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In a catted car smell is a very poor indication of richness, or unburnt fuel in the exhaust. A wideband isn't the only way to determine a/f ration, like I siad it was just a statement about being a way to truly know the a/f ratio.

Pulling a plug works too, but it isn't 100% accurate either....
 
reading spark plugs on a computer controlled EFI car is pretty useless...

people will argue, when in fact they are looking at the porcelain's color rather than correctly and accurately "reading the plug" which sometimes includes cutting the plug apart to see the "fire ring"...
 
but if you pull a plug and it's WET...that's a pretty sure sign something "goofy" is afoot.
 
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