Engine running rich, suggestions?

[ArticDragon192]

I have a 91 KA with dual exhaust cam set-up, NGK Iridiums, A guttet cat, and a RSR Exmag with 3in piping. After installing the catback, my car started running richer. I reset the ECU so it would remap itself to the new mods, but I'm still running rich. I shoot flames at times, and fuel can be smelled from the exhuast, so I know I'm running rich. I'm getting a cat right now to help increase backpressure a bit, but anyone else have any other suggestions to stop from running so rich? I already know I'm fouling up my plugs and I don't want 50 bucks wasted from running too rich. Thanks.

[UK-SRi]

Cam gears to dial out some overlap?? change the O2 sensor?, it is AFTER the cat I hope??Apart from that not sure really.

Mike

[ArticDragon192]

O2 sensor is new.

[onosqv]

It seems like the majority of the richness is coming from the exhaust cams...

Were you running rich before you installed the new exhaust? If yes, then adding a cat in will only foul up that cat... if not, I have a 2.5" hi flow .

SAFC + wideband is all I can suggest my friend, haha.

[sleepyRPS13]

you can always check for high fuel pressure.

[InsanityInc]

Uh, you may not be running rich.

If you shoot flames and smell gas that means you have unburned fuel in your exhaust, HOWEVER, that can be caused by a lot of things that are not rich running, in fact, unless your injectors are stuck open (which you'd notice in the drivability), you won't run rich enough to create noticable amounts of hydrocarbons.

My suggestion is to go get an emissions test (if you can). If the CO% is high, that means you are running rich. If CO% isn't very high, but your HC is way high, that means you're just getting unburned gas.

The thing that worries me about your original post is you say you have the "dual exhaust cam setup". Chances are you ****ed up the install and have too much overlap, which is causing your car to suck part of your intake charge out of the cylinder into the exhaust before the exhaust valve closes. You may not have noticed the problem with the stock system, due to exhaust backpressure stopping it from occuring, but when you switched to the larger exhaust, you just exacerbated the problem.

In other words, I doubt you're running rich.

[ArticDragon192]

By ****ing up the install, you mean I didn't install it right or that the set up isnt right ot begin with? Becasue I'm pretty sure I installed it right. I rotated the cam 4 teech counterclockwise so that it would be identaical to the position the intake cam was at at TDC.

[InsanityInc]

By ****ing up the install, you mean I didn't install it right or that the set up isnt right ot begin with? Becasue I'm pretty sure I installed it right. I rotated the cam 4 teech counterclockwise so that it would be identaical to the position the intake cam was at at TDC.

Problem is, doing that will give you a fair amount more overlap. I'm pretty sure the S14 cams are designed to work with a narrower LCA than the S13 cams.

[ArticDragon192]

But if there was a significant amount of overlap, wouldnt fuel be burnt throughout the exhaust when im accelerating. Because I only hear the backfire and shoot flames when im decelerating in gear.

[InsanityInc]

Most cars run rich momentarily when you lift off the throttle, and thus if you have a lot of overlap you're going to suck even more fuel into the exhaust than you usually would in that situation. It's why most cars with an aftermarket exhaust make popping noises when decelerating and shifting.

[ArticDragon192]

Oh, I see. That explains the popping when I shift every now and then. The thing is, it backfires randomly, when I'm already decelerating in gear. However, I'm glad to note that the ECU finally got the settings down right. When I first installed the catback, I got an mpg of 19mpg, something I've never gotten before. Now I've gotten an mpg of 24. I've only ever hit this amount like 2-3 times previous to the install, so looks like it's not running rich anymore, if it ever did to begin with