SR20 Forum banner

1 - 16 of 16 Posts

·
FWD PWNAGE IS HERE!
Joined
·
2,570 Posts
Discussion Starter #1 (Edited)
Realllly weird stuff going on here...
S13 with s13 redtop swapped in, has 50lb injectors, z32 maf, fmic etc.. and the car will not run right. Car runs extremely rich, fuel pressure is at 38psi with vacuum line hooked on the fuel pressure regulator, tps voltage is right, maf readings are right, o2 sensor for some reason gets off the wall readings.

Very odd thing is that the AICV is unaffected by any adjustment to it, o2 is acting really weird. Does anyone know if it matters what o2 sensor you use? I have had great luck just using whatever o2 with jwt ecu's but have not dealt with enthalpy before. Right now we are running a universal bosch o2. The bov is not being recirculated for all that it's worth. My buddy has tried adjusting numerous things on the car in order to figure out what is going on but the car continues to pour a black screen of smoke out the tail pipe. All we can think of is that the ecu is not programmed properly and MAYBE the o2 sensor is throwing things off.
I forgot to mention that this all could possible be caused by no intake pipe and the bov not being recirc'd? Just wouldn't make sense to me..

Can someone chime in with some thoughts on this. TIA
 

·
i try!
Joined
·
293 Posts
are you running a blow thru setup? since you have no intake hooked up.
 

·
~DIM
Joined
·
707 Posts
sounds like it could be the o2. IIRC the ecu will purposely run rich when it has a problem with the o2 being bad or just not reading properly.
and what brandon said, if you dont have an intake pipe, how is your maf connected?
are you throwing any codes?
 

·
Registered
Joined
·
953 Posts
You're supposed to check the fuel pressure with the vacuum line off of it.

43psi is the magic number.

What's the timing on the car? Supposed to set it to 15* base timing as Enthalpy advances/retards timing via the ROM tune.

When you say the TPS and MAF readings are correct, how are you checking them? Exactly according to the FSM procedures?
 

·
utahnissans.com
Joined
·
5,051 Posts
You're supposed to check the fuel pressure with the vacuum line off of it.

43psi is the magic number.

What's the timing on the car? Supposed to set it to 15* base timing as Enthalpy advances/retards timing via the ROM tune.

When you say the TPS and MAF readings are correct, how are you checking them? Exactly according to the FSM procedures?
Having the fuel pressure off a few psi won't create the issues he is describing and I couldn't imagine having the timing off one or two degress would create the issue either. Those are small tuning type things versus the car barely running and spewing black smoke.
 

·
Registered
Joined
·
953 Posts
He didn't even say what those values are, so how would I know what the timing's at?

It could be 15* BTDC or 0* of timing for all I know.

Fuel pressure might not be a big issue now, but why not fix it if it could potentially become a problem down the road?

Anyhow....

Did you guys check to make sure that the injectors are in good working order and not leaking fuel out or stuck open or anything?
 

·
Registered
Joined
·
174 Posts
I had a similar problem when had a bad O2 sensor, the car would pour black smoke under acceleration and i was fouling plugs every time i boosted. So im guessing your problem might be O2 related.
 

·
FWD PWNAGE IS HERE!
Joined
·
2,570 Posts
Discussion Starter #9
Yea I am going to have to check the timing to make sure but we hoping that wasn't the issue. It isn't a blow thru setup, the maf is right on the compressor of the turbo which I can see would be pretty damn bad so we are going to have the kid make up an intake pipe and throw that on to see if that helps. We have been meaning to check the timing but the owner didn't have a timing light every time we went to his house. I am also going to have him pick up the z31 o2 sensor since I am pretty sure that is what is supposed to be used. Please chime in if it is supposed to be something else.
 

·
~DIM
Joined
·
707 Posts
so uhh what else have you rigged up so the car might run?
cutting corners is a horrible idea and if you have cut any, go back and fix them properly!!!!!
 

·
Registered
Joined
·
953 Posts
If you want to be sure that the O2 is the problem, then just eliminate it from the equation, aka unplug it.

Just so you know, the SR ECU doesn't use the O2 other than when you're in a cruising situation. IIRC it doesn't even use the O2 sensor's input for idle... it may, but only for fine tuning the idle to achieve a lean condition at idle to save gas and for emission purposes.

I think the MAF might be the problem.

If the car starts with the MAF unplugged then you know the MAF is the problem. You're supposed to have the MAF at least 12" from the compressor inlet, as anything shorter will create too much turbulence for the MAF to read off of.
 

·
FWD PWNAGE IS HERE!
Joined
·
2,570 Posts
Discussion Starter #13
so uhh what else have you rigged up so the car might run?
cutting corners is a horrible idea and if you have cut any, go back and fix them properly!!!!!
Please don't be confused this is not my workings. I am trying to troubleshoot this for someone.
 

·
FWD PWNAGE IS HERE!
Joined
·
2,570 Posts
Discussion Starter #14
There is your issue.
We put the new intake pipe on and that didn't solve all the problems. We put on a new o2 sensor and a few other things and from what the kid was telling me it runs great for him now. I guess it was just a combination of all the little things. We will see how it runs after another week or so of running but so far so good.
 

·
~DIM
Joined
·
707 Posts
awesome, its always good to finaly get the thing fixed. if you read alot of the threads on here, they just kind of die in the middle with no results. if he has ne more problems though, tellem he needs to post and ask questions! :) :)
 

·
FWD PWNAGE IS HERE!
Joined
·
2,570 Posts
Discussion Starter #16
awesome, its always good to finaly get the thing fixed. if you read alot of the threads on here, they just kind of die in the middle with no results. if he has ne more problems though, tellem he needs to post and ask questions! :) :)
Yea it makes it hard to find answers when you go reading through all these threads that have similar problems with their ride and then they never post up how they corrected it ahah.
 
1 - 16 of 16 Posts
Top