weird idle and stalling issue since work done

[rustest86]

ok i have just done a bunch of work on my SR, none of which shouldve affected the idle and its ability to startup.
i resealed the timming cover, upper pan , lower pan, light weight pulleys " not the ballencer", 15lb billet flywheel, a new disk for my ACT SS clutch, i cranked the waste gate arm down more, new rack and pinion and changed the power steering pump. i have sti injectors with a fmic, a greddy 18g turbo and emanage. this setup ran perfect before pulling the motor last monday 10-25-10. i just got everything back togther on the 1st. its had an erradic idle since i started it back up, which i found muliple boost leaks that i fixed. last night i went to do some retunning for more boost. i made it less than a mile down the road and it started idling REALLY weird at a stop light then died and wouldnt start back up. lets just say there was a episode with the local cops were they INSISTED on pushing my car or calling a wreaker, instead of waiting for my friend come tow me. but anyway right after they pushed me my help got there, and this is were it gets interesting.
we checked for fuel, had that, and the exhaust reaked of raw gas
checked the plugs and for spark, had spark, lots of it. and the plugs were dry too. still wouldnt start though
i could understand all of this if the car had never started back up when i put it back togther, it wouldve been a timming chain or cas timming off, but the car ran 5min prior, and had been started and ran 5-6 times prior. so we started towing it home, and half way back i tried to start it again. and it started like nothing was wrong and ran perfect, except for the eradic idle. we tried but couldnt get it to do it again last night, so me and all my friends are stumped.

in advance sorry for such a long post i just wanted to throw everything on the table at once. i know somewhere someone has had a simular issue.

[USMCgetsome]

sounds like a failing maf. Check its output voltage at idle and wot post back up.

[PyR0NiAk]

Failing maf is definitely possible, but usually a failing maf means your plugs are going to be black. I'd bet more along the lines of a loose connection... CAS or MAF most likely.

[rustest86]

ok well after work and family stuff i finally got a chance to check this thing out. now this is all at the new 15psi level, and idling aroung 1300rpm. i had a q45 maf on it and it read 2.01v at idle and 4.8 wot output from the emanage. i all so tried a z32 maf and it read 1.45v idle and 4.5 wot output from the emanage. the idle quility didnt change with changing the mafs. now what did help was playing with the timming. but what fixed the idle issue was a new cas. it also started this weird stuff about cutting out around 5-6.5k to red line if i get over 13psi. which is around 4.5-4.8 volts on the maf. with my old cas the cutting out is a WHOLE lot worse than with the new one. we also checked and changed plug gap and changed #3 plug after we found the electrod starting to melt. we also tried a set of colder plugs, which didnt help.

so i do think i found out why it wouldnt idle right and that was the cas going out. but now i have this other issue which i think is related to my emanage now, the imput maf voltages are alot lower than the output. like 3.1v imput to a 4.8volt output. which tells me i need to lower the boost back down untill i either get the ecu itself tuned for a different maf or a different kind of fuel management system. i think its going into fuel cut because its maxing out the ecu maf voltage. i guess im gonna look into the nistune system so i can really change the maf setting instead of it being itercepted and converted.

anybody want a emanage and plug & play harness for a s13 SR?

[PyR0NiAk]

Glad you figured it out. The CAS was what had my attention, which was I figured it had a loose connection. Odd how it s*** out on you...

[rustest86]

yeah well at least a friend had a spare new cas. but it sucks because i have reached the max threshhold of the emanage on a stock ecu, such a bummer though. it pulled like CRAZY till it cut out, which is why i think it started to melt #3 plug and speckling the others. it would go from 11.5-12.3 afr to beyond 18 when it cut out in boost.

[USMCgetsome]

think of it this way. Had you not had that emanage you would not have been able to see the voltages from the maf or cas so it helps to diagnose. I agree that the nistune is a better route to go.

[rustest86]

yeah the emanage was great, and i think it still is. but its still nothing more than a complex SAFC, and my setup is outgrowing it now. also because of the melted plug i decided to do a compression check yesterday. 145,145,145,147 across the board. kinda on the low side but thats a cold engine and a tomei 256 exhaust cam too. but really, this has been one the best, most resistant motors i have built. over 30k since it was rebuilt 3.5yrs ago and ALWAYS having the guts churned out of it, and its on its 4 transmission now. damn them 200k+ KA trannys. i finally got my hands on a used 30k SR transmission. anyways, i found the nistune boards for $240 and the consult cable was $100........ seems too cheap to be true, but i've heard very good things about it.