PDA

View Full Version : What should I do about this?


oXeNo
03-11-2012, 05:44 AM
So I ended up with a sr20det swapped s13, which is pretty much confusing the hell outta me. It has a precision sc61 turbo, tial 38mm wastegate, and when I got it, it was running 15psi. At the time I didn't know much about nissans, I used to be a honda guy. But anyways, from what I can tell it is still running stock injectors, probably stock fuel pump, stock maf. I soon turned down the boost to around 10, I did a compression test and got 150 on all cylinders dead even, so it isn't bad. But I would think it would be maxing out the injectors at boost levels like that? Cause that sc61 has to be moving a lot of air. It has a Mines ECU which I believe is stage 2, and when I put the stock ECU on it, it runs extremely rich, pretty much pooring out black smoke. But what else gets me is the AFR is around 12.0-12.5 in boost at WOT, no cutting out or anything. So I was just wondering what I should be doing about all this? I am not driving the car much, just the ocassional here and there to test some changes I have done to the car. But I know I should get bigger injectors if these are stock, and I have a q45 MAF sitting around that I got with the car to install. I have an ECU that has already been chipped but I doubt tuned. How safe does it seem at the moment? Cause from what I have gathered this is a terrible set up and sounds like it would destroy the motor? :picardfp:

89JDM240sx
03-11-2012, 06:45 AM
Get a Z32 Maf... Upgrade injector to 550's a pump and retune your should be fine

oXeNo
03-11-2012, 06:57 AM
Thanks for the reply, Well I have a q45 sitting around it came with the car that would work fine wouldn't it? But I will get on that, what brand injectors should I get? I've heard about the STi injectors that are side feed but I doubt I could find one of those around here in a junkyard or so. So I would rather just buy some new. And a walboro 255 should be fine shouldn't it?

Kingtal0n
03-11-2012, 12:48 PM
There is no way OEM 370cc injectors could support any kind of 15psi, or even 7psi, from an SC61 turbocharger. The engine by now would be a molten slag of iron if it kept running like that.

The "chipped ecu" probably has a program for upgraded injectors, which is why it runs so rich when you plug on the OEM ecu. OEM injector On-times with larger injectors would put you anywhere from 20-80% too much fuel, Ill bet it it within that range because most injector upgrades are 550cc/740cc.
also an oem fuel pump will usually not support a T-25 @ 7psi on an SR20DET, so there is no way the oem fuel pump is installed.


What doesnt make any sense is you are saying OEM MAF sensor. an OEM maf sensor will not support an SC61 at 15 psi, even 7psi is very unlikely. please post pictures of these "OEM Injectors" and "OEM MAF" you might be looking at a Z32 maf and a set of 740cc injectors. Also pics of this SC61 would answer some questions.

oXeNo
03-11-2012, 05:53 PM
Thats what I am thinking, But I went and looked and the injectors and they look stock as can be, and I know for sure the maf is the stock one cause I looked up the model numbers on the side of it to make sure which one it was, cause when I hooked up the Q45 maf to see what it would do, it just ran rich at all times. But yeah I completely agree with you, I am just saying what I have been told and what it looks like to me and what is confusing the shit outta me, but I am not driving the car, I have a few times but not much. But here are some pics

http://i679.photobucket.com/albums/vv152/I3ROK3N/IMG_0160-1.jpg
http://i679.photobucket.com/albums/vv152/I3ROK3N/IMG_0146-1.jpg
http://i679.photobucket.com/albums/vv152/I3ROK3N/IMG_0157-1.jpg

oXeNo
03-11-2012, 11:32 PM
Ok I went and checked a few things today after I woke up, I removed the fuel pump and it isn't the stock one I suppose I do have probably a walboro 255 from the size and everything of it. But I still dont know about the injectors

Nkelley
03-12-2012, 12:43 AM
theres a good chance u could have a set of deatschwerks injectors since they look oem. only way to be sure would be to have them flow tested tho. 12.0 : 1 at wide open throttle is fairly rich and no way 370s would get you that kinda afr with that turbo.

im confused at your post tho, does the car run fine with the ecu it came with? you seem to be second guessing your set up but you never mentioned why other than because things "look" oem

oXeNo
03-12-2012, 01:13 AM
I mean it runs fine, other then the occasional boost problems but I am pretty sure it is my crap boost controller, hopefully not the waste gate. Yeah that was what I was thinking about the AFR believe me, But I was just second guessing cause I have no actual specs on the Mines ECU to see what I should be running or what it requires for the SR20. The only real problem I have is it won't idle, it will sometimes but it'll just go lean as hell on the afr when it tries to idle. Sometimes it will sometimes it wont. But other then that it seems to be fine, no problems in boost just problems keeping boost at a steady flow. Im going tomorrow to pick up a new walboro 255 because my fuel pump seems to be acting weird anyway. I pulled the injectors our a minute ago and they said JECS and made in Japan, on the top they say A46-00, 2E504701

oXeNo
03-12-2012, 04:57 AM
It also just really isn't a matter of it not running right, it's I wanna be completely sure that my set up is ok to be able to drive and not have to worry about something blowing up or my AFR being to lean. If it turns out that these are stock injectors, what should I go with? I am kinda on a budget, i have been looking at the Five-O 550cc ones and the Deathschwerks as well. like I said I am going tomorrow to pick up a walboro 255, just to make sure nothing is wrong with my fuel system cause Ithought I had a walboro at first but it turns out it wasn't a stock one but from what I found on the internet it isn't a 255lph pump.

oXeNo
03-12-2012, 10:56 AM
Well just incase I found a good set of STi Yellow Top Sidefeed injectors and had them shipped out today! So just to be safe I got a good deal on these for $150!

Nkelley
03-12-2012, 08:54 PM
before you spend a bunch of money you really should get one of the ones you have flow tested, if afr's are where they should be why change injectors because your not sure what they are? If you put those 550's in and they're significantly smaller your gonna run lean and then you really will have an issue.

oXeNo
03-13-2012, 12:24 AM
Well I talked to the previous owner today I asked him about the injectors and he said that if they are the blue top ones that I have, They are deffenitly the stock ones. But I understand where you are coming from, the STi injectors weren't very expensive and if they work, will be a good cost effective upgrade.

Pro ViZIon
03-13-2012, 09:28 AM
The sti injectors are a good deal. They're 425cc I believe. And the injectors you have are definitely stock. Jecs is an oem parts manufacturer for Nissan.

oXeNo
03-13-2012, 02:35 PM
The 04 STi injectors are supposedly rated at around 520cc I believe. I think it just depends on what year and if you get the JDM or USDM I think. But thanks for clearing that up, I pulled them out and just waiting for the STis to get here.

oXeNo
03-16-2012, 10:45 AM
Well I thought i'd let you guys know, I fixed most of the problems. I got a new walboro 255 put that in, waited for my injectors to get here, just finished wiring in the plugs a few minutes ago,started right up and idled really good for running hellla rich! It sits at like 10.0 on the afr so I only ran it long enough to let it warm up to see if it still idled, and it was great! So now time for a new tune! with a bigger MAF as well! Thanks for the help guys!