strange emissions removal problem

[dsm5062]

I am having a strange issue that I can not figure out,I am at my wits end
It started after I did the emissions/charcoal canister delete, and sealed a leak at my map sensor. I started it after putting it back together and it was extremely lean and would stumble when reving it. I took it down the road and it stayed in the 17:1-17:8 area and when I tried to hit a lil boost to see if it changed it only dipped to the 15:0-15:5 area. I boost leak tested it and it only seemed to have a signifigant leak at the injector o-rings which I fixed and still no improvement. I thought maybe it was the map sensor so I changed it with new one and nothing different. It doesn't seem to build any pressure,even the bov doesnt seem to vent right it flutters instead of actually venting. I need help as soon as possible this is my daily driver down. It is a 95 gsx with the 1g motor swap, built bottom end 9:01 compression,small 16g,greddy small fmic,rfl bov(non-recirc),stage 3 dsmchip,560 evo injectors.

 

[jrohner]

What did you do with the EGR -- blockoff or leave it on and just not hooked up to any lines?

Did you plug the charcoal canister lines? You don't want to run them together.

 

[dsm5062]

I made an egr block off plate, and I followed taboo's guide for removal of the emissions system. all the canister lines are removed from the solenoids and throttle body nipples,and the solenoids are still electrically plugged in to prevent a cel.

 

[rush2252]

Extremely lean at 17:1? this is rich. Lean is like 11:1 It sounds like the thing is running PIG rich like all 2gs. Make sure you have your vacuum lines ran like this. http://www.dsmtuners.com/forums/art...-speed-shop-vacuum-diagram-removal-1g-2g.html

But please dont T the line for the MBC and BOV the BOV needs its own source as does the MBC.

 

[dsm5062]

Isn't that backwards? I'm running the aem wideband and it's pegged in the red at 17:1 afr 10:1-11:1 is in the green in the rich area... maybe I'm wrong and I do have the tap from the manifold feeding the boost gauge and fpr, I do happen to have the bov tee'd into the same source. should I feed it from the "p" nipple on the throttle body instead? and the mbc is tee'd in the wastegate line from the compressor housing.

 

[rush2252]

Isn't that backwards? I'm running the aem wideband and it's pegged in the red at 17:1 afr 10:1-11:1 is in the green in the rich area... maybe I'm wrong and I do have the tap from the manifold feeding the boost gauge and fpr, I do happen to have the bov tee'd into the same source. should I feed it from the "p" nipple on the throttle body instead? and the mbc is tee'd in the wastegate line from the compressor housing.

Run the MBC inline with the compressor cover nipple or the j pipe depending on which turbo your using. As for the FPR and the boost gauge that is fine. Im running mine like that without any problems as for the AFR 17:1 is really rich

 

[stefanOst]

Run the MBC inline with the compressor cover nipple or the j pipe depending on which turbo your using. As for the FPR and the boost gauge that is fine. Im running mine like that without any problems as for the AFR 17:1 is really rich

No I'm pretty sure the OP is correct, you have it backwards, 17:1 is really lean. 11:1 like you mentioned before is right in the butterzone for tuning, not really lean.

 

[dsm5062]

what does the dsm ecu use to reference boost if the mdp sensor is just for egr function?? I was thinking maybe its the sensor not reading,and would a bad maf reading cause a lean condition and the stumble?

 

[cheap90gsx]

Toss the rfl bov. IMO POS...

 

[dsm5062]

yeah it was a cheap replacement from a friend at the time i plan on upgrading,but i need to figure out my bigger problems before I worry about the bov.

 

[jrohner]

what does the dsm ecu use to reference boost if the mdp sensor is just for egr function?? I was thinking maybe its the sensor not reading,and would a bad maf reading cause a lean condition and the stumble?

The ECU doesn't see boost, it reads airflow from the airflow sensor. Also, the stock MDP on DSM's (as well as USDM Evo 8/9's) is just a 1-bar, so it doesn't even read boost (maybe like 2 pounds or something).

You don't need the MDP as it does nothing to the actual tune of the car, it's only job is to turn on the CEL, basically the same job the rear o2 sensor does. I love useless sensors that do nothing .

 

[dsm5062]

I'm glad somebody could finally answer that for me, I was pretty sure thats how it worked but with the symptoms happening right after i messed with the mdp I began to question myself. Is it possible that the maf could cause the lean condition,when I got the car the previous owner had removed all the honeycombs I just did order a new one today.

 

[turbotemper]

Id bet that is part of the problem. Almost everyone that has taken the honeycombs out soon have rich condition issues which make the car run like shit. You have extremely lean conditions. Which means there's more air than fuel in the mix.
What are you using for tuning? AEM EMS?
It sounds like you have the proper fuel system upgrades to support that turbo etc. You might just need more fuel in the mix.
Do some data logging as well to see whats going on. Have an experienced person/technician dyno tune it for the best results.

 

[dsm5062]

It was running fine before it just kinda happened randomly. I am tuning with a keydiver chip from jeff o. set for the injectors and an safc to fine tune it. As for dyno tuning unfortunately there aren't any awd dyno's in the surrounding area,I think atlantic motorsports is the closest shop to me. And I definately can't afford that yet

 

[dsm5062]

UPDATE!!! Solved my problem,it was the mass air stopped reading correctly.Just put the new one on and it idled where it should,a/f is dead on Thank God I missed my daily driver!! And if anyone needs one go to advance auto parts and ask for one from Rightchoice it's advance's own salvage yard, it only cost me $80. If anyone needs help getting one just PM me I am the commercial sales manager at the advance auto in berlin,md.