Loli_Driver

I finally decided to make an account after lurking for 2 years, so please bear with me being new to the forum and also a fairly new SR/240SX owner

I have owned my Redtop SR 240 for about 2 years now. I recently replaced my fuel injectors because one went bad and caused a misfire, this is where my problems get exponential. I bought the car from some guy who was giving up on his project to fund another one of his projects. Long story short the car has a decent amount of mods. I'll list the mods from the original craigslist post, and also my own additions.

Engine Specs:
S-13 Sr20det red top engine
*Turned crank, polished, balanced
*King race bearings (tri layer) main, crank, thrust
*NPR piston rings (nippon)
*TOMEI 264 Pon cams
*ARP head bolts
*APEXi head MLS head gasket
*PHASE2 upgraded oil pump
*FRsport rocker arms, timing chain kit, including tensioner and guides
*JWT gt2871r turbo
*ISR Braided turbo lines
*Mishimoto radiator
*Godspeed intercooler pipes with Spearco intercooler
*HPS silicone radiator hoses
*HKS ssqv blow off valve
*GReddy rocker arm stoppers
*NST aluminium pulleys
*Circuit Sports aluminium overflow tank
*Megan turbo manifold
*Megan turbo elbow
*Megan down pipe and full exhaust system


Drivetrain:
*ACT super street/strip clutch
*TEIN coilovers type II he coilovers with adjustable camber plates and pillow ball mount
*TEIN inner tie rods
*kazama Tension rods
*Energy suspension bushings throughout the enitre rear end, and sway bars
*JDM VLSD rear end with fresh fluid (works awesome)
*JDM 6 bolt axles
*New wheel bearings up front
*300ZX big brake upgrade kit 28mm iron in the front (rebuilt)
*Brembo slotted rotors up front with stainless steel brake lines

Wheels/Interior add ons:

*RHDjapan torque dampener
*AC autotechnic oil pressure gauge
*4 Color faze led boost gauge
*AEM UEGO wideband

So now my problem. The ecu for my car has a sticker on it that says emance, some of you are probably familiar with that. This sticker had written on it 4 things SR/6+2340/555cc/N62. I know that that 555cc should be for the injectors size, and N62 is a z32 MAF sensor, idk what 6+2340 is tho. This is where the confusion starts, because I still have the stock MAF sensor, not a z32 N62. Now with this information, I decided on stupid intuition to buy a set of Tomei 555cc injectors to replace mine. And today I finally got around to replacing them. Everything went fine, but now my car runs extremely rich ~10.7. Before it was running a little lean anywhere between 13.7 all the way to the 16s not(for what I could tell) dependent on load. Because of this change in AFR I am led to believe that it was running stock injectors this entire time, which I should've figured out on my own based on the color, but I had "broken car upgrade brain" nonetheless.

This is probably a simple solution, I just don't have the money right now to buy a N62 MAF and test that out, or to do a retune, so I wanted your guys input. Ill put some pictures of my "Build." Any questions are appreciated, thanks for looking at my noob thread.

https://imgur.com/a/8N7X1Dt here is an imgur album because the pics were way too big to be embedded

Kingtal0n

The fix is to buy parts that you actually know work together

for this setup you need minimum:
power FC L-jetro
Z32 maf
740cc side feed injectors
+22psi~ Pressure test, accurate timing test (verified with 2 lights), and compression test (verified with 2 compression testers)

anything less is a waste of time and energy
You might get lucky by experimenting with various sensors or computer or whatever...
however unless you are a really good engine tuning expert the setup will not last long. because it may run fine but there will still be issues that you are incapable of understanding or realizing. An engine will 'run fine' anywhere from 11's to 15's but it requires a very specific number during idle, cruise, wot, transitions, etc... you can't let it wander into the 15's at WOT and you can't let it go 13 at idle for example. Same thing with timing, the engine will 'seem to run fine' anywhere from 10* to 40* but it needs very specific numbers at WOT (9 to 10* usually) and very specific numbers for cruise (34 to 38* usually) and if the wrong number is showing up at the crank you wont have any indication, engine will run fine up until the cylinder will just melt.

If you think that buying a 240sx is going to be cheap or that it won't need parts constantly thats crazy

Loli_Driver

Sorry I went to post this thread like a week ago and it took forever to get approved. Since then I've already decided what I'm going to do for now. I really don't understand why I would need half the stuff you listed, I'm just going to get a z32 MAF, and then RS Enthalpy tune when I get the funds. I already did a compression test and all the cylinders are fine ~155.

S14rebuild

Best way to resolve it!

Kingtal0n

half of the stuff?

I listed 3 items:
maf
ecu
injectors

Which you need all 3 (not half) no matter what

The maf because obviously you need a maf, even if you have a maf you should have a second maf as a spare and to diagnose with. So thats 1/3.

The injectors because you have no idea what injectors you have which means you can't tell Enthalpy which injectors you have which means he can't set the delay time correctly. He will need to guess. And if that timing is off by .2 seconds the engine will idle rough or lean or rich or some other way. And because its a rom tune you have no control over the tune to adjust for that. And also nobody should be using 550cc injectors since 2009, thats 2/3 needs to be replaced anyways.


And the ECU which you need something to tune the engine with. 3/3 = 100%
A used PFC is 500 an ROM tune ecu is 500. I got a used PFC for 350 from ebay last week.
Nothing wrong with ROM tune- but it is very limited. You cannot change anything yourself, ever. You cannot adjust the tune at all. You have NO control. So it is the worst possible option for people who wish to have control over their engine. You will be stuck mailing it back and forth everytime you make any change to the engine.

and YOU have no idea what you are saying or doing, no business giving tuning advice, what a joke 'best way' lmao- yeah stack unknown tiny injectors with a hard-coded rom tune on a maf capable of supporting twice the injector size. is a great idea. What a combination of parts

S14rebuild

Lmao...u feel better now?