View Full Version : skyline: 1 me: 0

03-04-2012, 01:09 PM
well the time has come for me to ask for help. I have researched up and down, tried many different remedies and I have not solved my running rich problem I think either my ecu is fried, turbo is blown or i just need a tune. this is what is happening and what I have done
my 1992 GTS-4 RB20DET is running rich like verrrrry rich. the history on the car is as follows :
from japan
had a SAFC hooked up to ECU but for some reason was ripped out with wires still attached to ECU
had a turbo timer, aftermarket alarm that I took out and made sure no loose or random wires were left behind
from what I can see the motor is all stock

what I have done:
replaced MAF with known working MAF from RB20
replaced O2 sensor with brand new one
replaced coolant temp sensor with known working unit
checked coil packs they looked fine but do not know if they are bad
changed spark plugs to BCPR6ES or something like that

unplugged tps while running the black smoke got worse ran like poop
unplugged MAF and couldnt rev past 2k (limp mode as it should)
unplugged O2 black smoke got worse

what I can see and hear:
turbo sounds very unhappy like a ticking i guess you could say? either way not what I want to hear from a turbo
black smoke from exhaust not blue or white

when at idle NOT IN GEAR i can rev the car through a "full cycle" smoothley up to 6 or higher no hesitations but as soon as it is IN GEAR and I try to drive off the car goes into limp mode and cant rev past 2-3k and just hits a "rev limiter"
when i put the ECU into diagnostics mode I get a "55" and when i test the realtime O2 sensor the LED is off signifying it is running rich. I have looked for boost leaks I have checked grounds etc. im at a loss. any help you have is awesome.

I am thinking the ECU is blown or needs a tune and the turbo is about to be shipped off to be rebuilt and made hybrid.

p.s im sorry for the length and if you made it this far to read this then your awesome and I really appreciate you reading this and I really hope this isnt a "noob question" and yes I have researched.

thanks everybody for helping me out I owe you big time

03-04-2012, 01:20 PM
Check the ecu harness where the safc was connected.

03-04-2012, 01:47 PM
its all protected there no bare metal showing, I will double check again though just to be safe, thank you =)

03-05-2012, 01:00 AM
black smoke means ur burning oil?

03-05-2012, 01:32 PM
I could be but im not having to add any more oil, and it just smells like gas leading me to believe it is rich but why I do not know

03-05-2012, 04:38 PM
white bluish smoke means you're burning oil.

03-06-2012, 01:28 AM
an injector or 2 may be stuck open.

03-06-2012, 01:46 AM
black smoke means ur burning oil?

Burning oil: blue smoke
Burning coolant: white smoke
Running rich: gasoline

03-06-2012, 06:41 PM
i agree with the stuck open injector or injectors i would pull plugs and check for fouled plugs if they look good i would double check your timing and tps. my car would rev up fine but then when it got load it ran like crap. i adjusted the timing and tps and it ran alot better.

03-07-2012, 02:15 PM
What colour are the injectors?

03-09-2012, 07:11 PM
Make sure that the MAF signal at the ECU is contacted when i got my RB20 it always was prewired for SAFC and the wires need to be together... its sounds like its MAF related since it will not let you REV.. Check and make sure it hooked up

03-13-2012, 02:43 PM
the injectors are red like they should be, i just changed plugs again today with BCPR7ES, changed TPS out, checked vacuum lines again, i noticed that there is a hissing noise coming from the cylinder 6 area, maybe injector, so I am now going to seperate the manifold and check the injector, i was holding off on doing it but now it seems like that is the only hope, my buddy has a set of stock rb20 injectors as well so I will be able to replace them if found bad. thanks everyone for your help hopefully soon it will be up and running again, i am trying for april 6th it is the opening of the nurburgring and a cruise with some of my skyline buddies.

03-13-2012, 06:53 PM
Sounds like a vacume leak if your hearing a "hissing" noise. Take a can of brake cleaner and spray some around that hissing area. If your idle changes when you spray in that area then you found your vacume leak or leaks. Could be an injector o-ring is bad.

03-18-2012, 04:59 AM
UPDATE: still not running as it should, I have:
checked coil packs all within serviceable limits
tested the ignitor/ignition module? on top of the last two coil packs, all pins were the same except three of them two were higher than the rest and one was very low, I was not sure the exact resistance or number for continuity, or even if i did it right but by process of elimination it was bad so i replaced it
the other peice i have an extra of is the injector resistor, how big of a role will this play in running rich?
I have also changed the TPS, Injectors, and played with the timing a little bit nothing is really doing it, i ran it this morning and the smoke is still pretty black i wasnt sure if it was just burning off the old junk or what, but I have a friend bringing a consult cable over tomorrow hopefully and we will figure it out, but in the meantime any suggestions?

03-19-2012, 08:48 PM
check your fpr it may be stuck that might be ur rich problem.

03-27-2012, 01:37 PM
not fpr's just changed them, theres still a small vacuum leak at the rear of the engine bay, i cant seem to find it visually or with brake cleaner, i tried to drive the car again after finding and repairing a ground wire on the ecu, it drives like a sensor is bad or something, i have a diagnostics cable on the way, so we will see soon enough, ive been studying the FSM and writing down all the correct values for all the components.

04-03-2012, 08:42 PM
u should only have 1 fuel pressure regulator the other one is like a check valve to hold fuel pressure on start up from what i understand. i dont even have that one on my car any more. did the car just start doing this or did u buy it this way? if u bought it this way it may have a stronger fuel pump and causing it to run rich u need to put a fuel pressure guage on it and see if the fuel pressure is higher. u may have a blockage in the line somewhere in the return. not likely but if u ran something over u may have crimped a fuel return line.

03-20-2013, 02:26 PM
if you still have the problem i think its a fuel or possible turbo problem because your getting too much gas but a blown turbo can restrict air causing a rich fuel state