Sulphur smelling exhaust!!!

[Steve]

I got my new combo together over my semester break. WoooHooo! It actually runs, but I have some issues.

1) I can't get my BBK regulator below 41psi w/ vacuum disconnected, plus it bleeds off all pressure as soon as the car is shut off. Not a big deal, I can get a Holley from Jegs for $60.

2) I hated the Magnaflow tails Now I just have turndowns, wasn't sure at first, but the look is growing on me.

3) The most concerning, the sulphur smell. The exhaust smells normall at idle, not rich like raw gas or sulphur or anything. The only time I get the nasty smell is when I rev the car up, It smells disgusting!!!

I have a thought that with my 24lb injectors, 41 psi of fuel pressure is way rich for my combo. Please tell me what you guys think.

Timing is set @ 14* BTDC...........Thanks in advance :rotate:

[Macs Stang]

does the exhaust smell burn your eyes as well? if so, i would check your o2 sensors maybe, some thing have screwed up with them.

[mnstang]

good idea ditching the the magnaflow tips, but do you mean turndowns at the mufflers.... or are you running turndowns at the tailpipes? cuz that would just look really weird on an lx. and i have the holley regulator, had it almost 2 years, not one complaint. but can't you rebuild those bbk regulators? if it's bleeding pressure, your diaphram in you regulator is probably ruptered, either that or you pump is letting it back through, could be a problem in hot summer weather (dreaded vapor lock). And are you running cats still? because if you're running too rich, and running cats, it'll start smelling like rotten eggs. And it is trashing your converters (if you are indeed running them).
Well all combos are different, it's hard to say what an optimum fuel pressure is to run without getting on a dyno with an a/f meter. alot of things come into play with that, so it's hard to say, but usually it would be less than 41 psi.

[Sweet35th]

What did you do now? (what was added to your car)

If the regulator was ruptured there would be fuel in the vacuum line to the regulator. THe main question on the bleed back, is weather fuel is training back on the supply side, the return side, or via an injector into a cylinder. I have a few tools to block off the return line and supply line to test this.

New exaust, has a pretty horrible smell as it burns in. The chemicals used to coat the pipes is pretty bad, and all brands off exaust are different.

Also if your car has sat for a while with old fuel. Old fuel will burn off poorly, and give off a noxious smell.

As for your fuel pressure, I can hook up a DVOM to your O2 and get it pretty close. On the dyno is the best option.

[GarrettGTX]

yeah but tims right man i dont have my o2s hooked up adn damn it burns the hell out of your eyes whooo doggy

[Steve]

Ok, here's what I did to her. Put in my ported E7's, an E-cam 4* advanced, TrickFlow Street Heat Intake, New dampener, new roller lifters, 24# injectors, w/ matchind cal. tube for my C&L meter, new magnaflow cat x-pipe, and magnaflow catback. I put the turndowns after the mufflers... I'm not retarded Greg




The exhaust smells totally normal at idle with the vacuum line connected, I believe the pressure is somewhere around 30-32 at idle. The smell happens when I rev it up to about 3 grand and the regulator goes to full pressure, which I can't get below 41 psi. (BBK POS). When I had someone charge my lines for me I could hear the fuel flowing out of the regulator as soon as the pump stopped. Sounded like a trickling stream. I checked this out with the upper intake off so I could find any leaks easily, and just happened to hear the noise, so I checked it out and saw my guage on the schrader valve go right back down to 0.


No check engine lights or running problems, I'm thinkin' it's just running rich when the fuel pressure gets up to 41psi.

Thanks guys......

[Steve]

Do You guys think I should put my 19 pound injectors back in??? My combo should be good for about 280 horse are my 24's way too fat? I'm planning on getting a ZEX kit sometime so I wanted the bigger injectors. Let me know.

[Macs Stang]

i am guessing that the 24#'s should be alright. especially with the new cam and intake. maybe you need a custom chip as well since you have heads, intake and cam. i would also get a new regulator since yours went to shit.

[Sweet35th]

Well on your combo, its going to come down to how well your heads where ported. My buddy is running a very similar combo to yours and it is as fallows.

TrickFlow Cam .499/.510 221/225 so just slightly bigger than Ecam

Street heat intake

Ported E7TZ

1.7 roller rockers

C&L intake kit (was actualy worth 16rwhp on the dyno!!!!)

MAC shorty headers

Off Road X-pipe with flowmaster cat-back

The car made 267rwhp and 312rwtq.

[Novi2KGT]

Just wanted to add that I have seen a couple other BBK regulators do the same thing as yours, but one of them you couldn't change the FP at all.

[Steve]

35- was your buddy runnin' 24's???? I don't wanna go back to 19's but I don't wanna run way rich either.

[Sweet35th]

Hes running 19s right now. We tried a set of 30s that I had laying around and the car lost 5rwhp, running rich. If we would have had 24s they would be in the car, the car is on the spray as well.

[Steve]

Where do you guys go for dyno tuning, and how expensive is it??
I'd like to get this thing tuned properly, and get all I can out of her.

[Steve]

Here's another question- How low can I go with the fuel pressure before I lose good fuel atomization??

I'm just really concerned that If I am running rich enough to get that egg smell when I rev it up, I must be running really rich, Right?? Will lowering the pressure 4-5 psi make that much of a difference??

[Sweet35th]

I did all the tuning on his car, on the dyno.

An EFI car will suprizingly run on as low as 10psi fuel pressure, but not real well.

You would be able to lower your pressure down to around 35-36psi without noticing much differance performance wise. Once you get down to low 30s, high 20s you can feel it.

I recomend you setting pressure at 35psi (35psi with vacuum aplied) and try that out. Your going to need lessure pressure than you think, specialy running the 24# injectors.