So I have a 2002 6speed with a custom turbo kit. I haven't really posted anything up about it since i like keeping to myself lol.

quick description of car/build:
Borg Warner s362
e3 usa 38mm wastegate
godspeed intercooler (no more bumper support for me)
3in ic piping to my stock maf (03 beefier maf)
SSIM manifold + bop + spacers
OEM r35 gtr injectors
TurboXS Utec + map sensor
dumped wastegate to stockcatback (i know i know but i have a lot of exhaust leaks so its not as bad)

Here's the story, my battery wasn't getting charged so i redid the ground in back, terminals, and also did my accessory belt. at the same time i did the crank sensor because i was throwing a crank sensor code. before all this the car would cut out around 5-5500 rpm. im running the twin turbo 550cc aps twin turbo tune. the car runs fine and pulls great and is very rich. the gtr injectors are 570cc.

Ever since i did the crank sensor and the battery things the car now pulls to redline perfect. it doesn't chug, miss, or anything. utec isn't detecting a knock or anything, after i drove it for a bit and saw i can go to redline (only did a 2nd and 3rd gear pull) i continued to drive the car normally for another 20 miles. stopped often, shut the car off at a grocery store and it started fine and when i went to go to the mall about 3 miles away, i park the car and it shuts off on its own. idle didn't chug or miss it just completely died. now it does it every once in a while and it just randomly dies. once in a while i start it back up and it misses and wont run right, it dies, then i start it and its perfect again. I checked my ground but thats still tight, battery voltage in back was like 12.8-12.9 (i guess a little low at idle) and maf voltage is 1.3-1.5 at idle when it was running fine. i haven't had a chance to hook up my laptop to it when it acted up. i drove the car last night and it was perfect. any ideas???

I'm in between a bad maf, ground, low voltage, or faulty crank sensor.

the only codes im throwing are o2 codes, po132, po031 and i think po037

 

12.9 is not normal idle voltage. Recheck all of your grounds. Check if the battery is well grounded.

 

pics of the engine bay??

Maybe it has something to do with the crank sensor you replaced. I was running low voltage 12.9 at idle until I upgraded to the big 3 with 0 gauge wire all around. now its 14.1V at idle. Does the car take a long time to crank?

 

Before the bigger ground, belts, and terminals it idled at 12.1 lol.. it never died before though. How can I test the crank sensor? It's really close to the downpipe so I'm kinda worried I may be like heating the crank sensor? Could that possibly cause it to randomly die and run like *** for like 30 seconds and die, then fire fine?

It sometimes takes a few cranks and sometimes has a slow crank.

Where do you guys have your batteries grounded if its in the trunk?

 

well, i went to start the car today and it has a dead battery. on to figure out my charging problem before i figure out boost problems. could low voltage cause a car to shut off randomly like that?

it's not as clean as your setup (huge props btw, it looks awesome) i went over your thread and saw your battery wiring, i may do something similar.



idk how long that sticker will stay on, im getting sick of people asking if im with my gf still or not lmao. single TURBO, my CAR is single, not me lol.



i dont have hood struts on my cf hood so i use whatever i find for hood props.

 

Did the temperature change since its been idling then issues? Summer is just around the corner. Sounds like you may need to re tune the idle.

I had a similar problem with my Autronic SMC with turning on Air Conditioning on my Celica with the air condition clutch engaged. If it starts then stalls, chances are you need to add more fuel where your idling at to keep the engine running.

I had to add fuel fuel from 0 - 950 rpm (same fuel across the board) or whatever your setting your idle mines at 950 due to cams then right after 950 rpms I lowered fuel to stabilize the idle. You ramp it essentially.

For example (Fuel Map):

0 rpms - 65, 500 rpms - 65, 950 rpms - 65, then 1000 rpms - 35.

This knocks the idle back down to stay between 950 and 1000 rpms. Might be slightly different with the Turbo XS UTEC. But once I get my hands on the the patch harness and a wideband I should be a tuning pro on that next LOL. I would do the ignition similar as well to mirror the fuel. This is tuning concept please do not change your settings to match these examples. All engines and tuning software is different. You need a wideband and ability to view this real time.

For example (Ignition Map):

0 rpms - 18, 500 rpms - 18, 950 rpms - 18, then 1000 rpms - 15.

People don't realize you can run super lean at idle (if it idles right!). What makes a good idle is how well it is idling and if it is staying where it needs to be. It took me awhile to figure this out.

I can do it by looking at fluctuations in idle, coolant temp and ear. If you add more fuel and coolant temp goes down you are doing the right thing. You will notice at a certain point you add fuel and coolant temp/engine temp does nothing your just wasting gas. You need to find that middle of the road number where your coolant temp stays consistent , you can start your car, and the idle is stable. The best is when you have all 3 of these things with different weather conditions.

I could be wrong however since it sounds like you just did a few things. This is why in the future I highly recommend doing one change at a time then driving the car for a week to validate everything's normal. Anytime I do anything different on my Celica now it usually involves doing a re tune. I found the best thing is to tune on cold days. That way when its a 100 degree plus day you will be running more rich but you know you won't pop your motor due to temperature variations and run lean at high boost. Unless it is a fuel race car then id run separate maps for different outside temps.

 

http://www.mickandsarah.com/wrx/UTEC..._Part_Deux.pdf

Found this cool pdf for turbo xs utec tuning. But anyways sorry if that was confusing. I keep forgetting that turbo xs is a piggyback not full standalone so your really adding fuel over your stock ecu. Those fuel values are probably more in the 0 to negative range since your reducing fuel for larger injectors at idle. Do you have a wideband?

 

check for vac leaks after the maf, check the maf, what is your vac at idle and what is your a/f on decel

 

Cap off your turbo piping and put some compressed air in to test for vacuum leaks. I have a pvc cap with a compressor nipple where I can pump air into the turbo system to test for leaks. The video up top has a guy doing that. Don't put too much psi or stuff may pop off LOL.

 

Do u have a turbo install thread? I have question about where to rjn my feed lines from.