Too rich? SAFC? Shot Fire from tailpipe

[jmargelo]

I have a 95 gsx at 16psi with 3" turbo-back exhaust, no cat. I think that the fuel system is all stock, but I could be wrong. A/F gauge says that I am running very rich under full boost and WOT.

Is this possible at 16psi with stock fuel system?

Should I get a SAFC and lean it out a little?

Also, I hit 140mph last night and shot fire from my tailpipe. Any thoughts on this? Is it just because im running very rich with straight pipe? Is this going to harm my turbo(T25)? I also shoot black watery shit from the tailpipe.

 

[kpt4321]

A/F gauges just show the O2 sensor signal, which is always going to be rich at WOT.

You shouldnt be rich enough to shoot flames on a stock fuel system, not if it's working correctly. I'm betting money right now that you have boost leaks.

Don't get a SAFC just for this, the solution lies elsewhere.

Do you own a datalogger, or have access to one?

If the black watery soot comes out at idle after a cold start, that is normal. It's condensation. If it comes out when the motor is fully warmed up....

Hold your hand behind the exhaust tip and smell it. It shouldn't smell like fuel at idle.

Pressure test!!

 

[jmargelo]

I dont have access to a datalogger.

The black watery soot mostly just comes out right after I start the car, but some still comes out when the engine is warm.

How do I pressure test? I know part of the reason the car runs rich is because the BOV is vented. I have the injen intake kit w/o a place to connect to the BOV. I bought the car this way. The car also only has one o2 sensor since it doesnt have a cat.

 

[kpt4321]

I wouldn't worry about the soot for now.

If you plan on modifying your car more, I would suggest you buy a logger.

To test for boost leaks, you need to build a pressure tester.

http://www.vfaq.com/mods/ICtester.html

The BOV won't make you run richer, except when shifting.

 

[RipperXX]

On the 2nd gens if you disconnect the 2nd O2 sensor I THINK it only throws a CEL, which could cause the engine to run a little more rich to be on the "safe" side.

You can buy a O2 simulator for this. The way I understand it is they just send a consitant stoich reading to the ECU so the ECU thinks the CAT is working correctly, when in your case you dont even have one.

 

[Trctnless]

w/o a place to connect to the BOV"

which means your venting to atmosphere w/o being in a blow thru set up. And since some air may be exiting the BOV under boost it will effect WOT tuning. This will make your car run ASS rich. find a way to recirculate your BOV back into the inlet stream. YOu can try everything else but untill thats corrected your rich, slow and stinky

 

[kpt4321]

Originally posted by Trctnless
w/o a place to connect to the BOV"

which means your venting to atmosphere w/o being in a blow thru set up. And since some air may be exiting the BOV under boost it will effect WOT tuning. This will make your car run ASS rich. find a way to recirculate your BOV back into the inlet stream. YOu can try everything else but untill thats corrected your rich, slow and stinky

He shouldn't be leaking air under boost, unless his BOV is totally useless and junk. He will leak air on the shifts, but that's not as big a deal really.

A pressure test, which I keep suggesting, will tell him if the BOV is leaking.