Running Rich

[Boostin_S13]

I am running really rich, Is there anything I should check or do? When its sitting at idle and you give it gas( like 35% or more) it just stumbles alot then after a couple seconds it revs up and smokes some, Also once it starts boosting it runs alot better but still smokes. I dont know whats goin on, Last week it was fine and now it runs like crap. I took all the charge pipes apart today ( Thought it may have been a boost leak) and still way rich. Is it possible my maf is dying or maybe I need a new O2 sensor? I can make a video if it would help.

My Setup HKS GT2510 ARC SMIC Exhaust and test pipe HKS SSQV Atmospheric vent ARC Intake box Walbro 255 fuel pump Everything else is stock on the engine.

I searched but didnt find any info that helped.

[c-rad]

If you are running a Walbro 255 High Pressure pump and running the stock fuel pressure regulator, then the regulator is probably being overrun so your base pressure is higher than normal. It will cause the exact symptoms you are experiencing.

[Boostin_S13]

Wouldnt it do that from the start though? It used to be fine last week and before, Ive been running it like this for a couple months now, and a couple before that on the stock turbo.

[originalsin]

does running rich have any negative effects other than wasting gas

[c-rad]

does running rich have any negative effects other than wasting gas

Shortens the life of your O2 sensor and severe richness can wash down the cylinders.

[Boostin_S13]

Not getting a good a/f ratio will kill your performance and If to rich you can get cylinder wash.

[c-rad]

Wouldnt it do that from the start though? It used to be fine last week and before, Ive been running it like this for a couple months now, and a couple before that on the stock turbo.

I dont know. Maybe your O2 sensor just died.

[Boostin_S13]

I will try and change it out see if that helps, Do you know of any sites/places that have a good price on them?

[c-rad]

I will try and change it out see if that helps, Do you know of any sites/places that have a good price on them?

http://www.oxygensensors.com

[Boostin_S13]

Edit Found what o2.

[c-rad]

Edit Found what o2.

zerothread?id=114952

[Boostin_S13]

zerothread?id=114952

Yeah found that thanks though, I ordered one for 85 200sx 1.8 It didnt say what engine code was so I hope this one works.

[JDMSIL80]

I suggest you get a FPR, SAFC & wideband and tune the map out.

I'm also running pig rich with 255 Walboro w/o the FPR. My A/F's is in the 10s range and the motor would cut out completely above 13psi.

[Boostin_S13]

I suggest you get a FPR, SAFC & wideband and tune the map out.

I'm also running pig rich with 255 Walboro w/o the FPR. My A/F's is in the 10s range and the motor would cut out completely above 13psi.

What turbo are you running?

[JDMSIL80]

GT28R

What turbo are you running?

[Boostin_S13]

I put in a new o2 and it runs alot better above 1300 rpm, no more smoke, but when its idleing or below it still runs like crap somtimes, Could this be because of the walbro fuel pump?

[Boostin_S13]

I also have 40 cm hg vacuum at idle I see that I should be seeing like 15-20 inches? Could I have a leak or am I about right since its in cm hg and not inches? I tried searching for a conversion table for it but I dont really know how to read the ones I found and I couldnt find any cm hg, just mm hg.
Modified by Boostin_S13 at 8:28 PM 4/30/2006