ka mess - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Thedriftbadger · 05-27-2015, 12:12 PM

Didn't think id need to post on here but im running out of ideas. Just a simple n/a ka in a 93. Everything stock. What its doing is lean popping like crazy any time i give it throttle. It will pop and spit a few times then hesitate, then slowly gain power again until around 3800rpm when it falls flat on its face. Im getting a speed sensor, injector leak, and knock sensor code. Its not a California car so i have no clue why im getting that injector code, especially since none of them are even leaking. Speed sensor isnt hooked up but that shouldn't affect anything, it was fine without it for a long time. The knock sensor code i have fixed before by installing a new sensor but now its back. Sensor looks fine. It did the same thing falling on its face around 4k then was fine after i changed it. Now that problem is back along with the other problem a stated.
What I've done so far:
New maf, no change.
New tps set according to fsm, no change.
Reset ign timing to 20btdc with tps unplugged, no change.
Cleaned throttle body, iacv, maf. No change.
New ecu, no change.

The engine has maybe 7000 miles on it since it was rebuilt. And was fine until about two months ago.

The last thins i can think of is the mechanical timing having jumped. But with only 7000 miles and no chain noise why would that even happen? Or my fuel pump or wiring to the pump is dying, leaving me with low fuel pressure which would result in a lean condition which could lead to detonation. Its a walbro 255 that was keeping up fine with the old ka-t that was in the car.

Im open to suggestions. Thanks.

spooled240 · 05-27-2015, 12:40 PM

Quote:

Originally Posted by Thedriftbadger

The knock sensor code i have fixed before by installing a new sensor but now its back. Sensor looks fine. It did the same thing falling on its face around 4k then was fine after i changed it. Now that problem is back along with the other problem a stated.

Sounds like your knock sensor took a dump. What was your replacement? There are some very cheap alternatives on ebay that I would avoid.

Thedriftbadger · 05-27-2015, 01:32 PM

Quote:

Originally Posted by spooled240

Sounds like your knock sensor took a dump. What was your replacement? There are some very cheap alternatives on ebay that I would avoid.

Well i just found a break in the main harness, only 2 strands hanging on for the knock sensor. With the ks and cts unplugged it runs 1000% better. This leads me to believe that the fuel pump and wiring to the knock sensor are subject.
I might just bypass the knock sensor with a resistor for now as i don't have time to pull the harness and redo that. It never sees the track, just a daily driver so im not too worried about it, I'll up the octane to be safe. And obviously change the fuel pump out as its starting to make noises now.

omgosh · 06-01-2015, 12:51 AM

Did you pull the fuel rail off the intake manifold to actually see if the injectors are leaking out the bottom seal or when under pressure? I would also check the resistance on the injectors (supposed to be 12ohms) just to follow up on that code..

EDacIouSX · 06-01-2015, 01:13 AM

damn... do you need a new fuel pump? I have an oem one out of my 96 s14 if you'd like it, you can have it for whatever shipping costs. it has ~160k miles on it and worked completely fine when I pulled it.

I was also going to suggest that with the symptoms you listed and fixes you've attempted, it sounds like it's a wiring issue to either your maf or knock sensor but looks like you figured it out.

Let me know if you need that fule pump.

Thedriftbadger · 06-01-2015, 09:17 AM

Yes i checked the injectors thats how i know they aren't leaking...

Anyway i ended up changing the pump. Found the filter sock completely clogged with dirt as well as more dirt in the tank. Weird because it was spotless last time i had the pump out. Anyway, cleaned the tank, new pump and sock. Changed the in line filter too. Im sure it helped as the car just feels healthier but it's still way down on power. It has to be the knock sensor problem still. Hopefully the resistors come in today so i can get that taken care of.

I'd like to add that although it looks like im just throwing parts at it, this is all shit i have laying around so i might as well lol.

Thedriftbadger · 06-03-2015, 08:22 AM

Knock sensor bypassed, runs absolutely perfect!

240x_Dreams · 06-04-2016, 10:34 PM

Quote:

Originally Posted by Thedriftbadger

Knock sensor bypassed, runs absolutely perfect!

Would you mind explaining how you did this by-pass. I have been dealing with a knock code for months now. I am over it. Will it fail visual smog check in Cali if i have a resistor on the harness?

05-27-2015, 12:12 PM	#1
Thedriftbadger Zilvia Junkie Join Date: Jun 2013 Location: ontario Posts: 305 Trader Rating: (0) Feedback Score: 0 reviews	ka mess Didn't think id need to post on here but im running out of ideas. Just a simple n/a ka in a 93. Everything stock. What its doing is lean popping like crazy any time i give it throttle. It will pop and spit a few times then hesitate, then slowly gain power again until around 3800rpm when it falls flat on its face. Im getting a speed sensor, injector leak, and knock sensor code. Its not a California car so i have no clue why im getting that injector code, especially since none of them are even leaking. Speed sensor isnt hooked up but that shouldn't affect anything, it was fine without it for a long time. The knock sensor code i have fixed before by installing a new sensor but now its back. Sensor looks fine. It did the same thing falling on its face around 4k then was fine after i changed it. Now that problem is back along with the other problem a stated. What I've done so far: New maf, no change. New tps set according to fsm, no change. Reset ign timing to 20btdc with tps unplugged, no change. Cleaned throttle body, iacv, maf. No change. New ecu, no change. The engine has maybe 7000 miles on it since it was rebuilt. And was fine until about two months ago. The last thins i can think of is the mechanical timing having jumped. But with only 7000 miles and no chain noise why would that even happen? Or my fuel pump or wiring to the pump is dying, leaving me with low fuel pressure which would result in a lean condition which could lead to detonation. Its a walbro 255 that was keeping up fine with the old ka-t that was in the car. Im open to suggestions. Thanks.

06-01-2015, 12:51 AM	#4
omgosh Zilvia Member Join Date: Mar 2005 Location: Tampa FL Posts: 210 Trader Rating: (0) Feedback Score: 0 reviews	Did you pull the fuel rail off the intake manifold to actually see if the injectors are leaking out the bottom seal or when under pressure? I would also check the resistance on the injectors (supposed to be 12ohms) just to follow up on that code.. __________________

06-01-2015, 01:13 AM	#5
EDacIouSX Post Whore! Join Date: Nov 2004 Location: Los Angeles Age: 38 Posts: 4,565 Trader Rating: (53) Rides Gallery: EDacIouSX Feedback Score: 53 reviews	damn... do you need a new fuel pump? I have an oem one out of my 96 s14 if you'd like it, you can have it for whatever shipping costs. it has ~160k miles on it and worked completely fine when I pulled it. I was also going to suggest that with the symptoms you listed and fixes you've attempted, it sounds like it's a wiring issue to either your maf or knock sensor but looks like you figured it out. Let me know if you need that fule pump.

06-01-2015, 09:17 AM	#6
Thedriftbadger Zilvia Junkie Join Date: Jun 2013 Location: ontario Posts: 305 Trader Rating: (0) Feedback Score: 0 reviews	Yes i checked the injectors thats how i know they aren't leaking... Anyway i ended up changing the pump. Found the filter sock completely clogged with dirt as well as more dirt in the tank. Weird because it was spotless last time i had the pump out. Anyway, cleaned the tank, new pump and sock. Changed the in line filter too. Im sure it helped as the car just feels healthier but it's still way down on power. It has to be the knock sensor problem still. Hopefully the resistors come in today so i can get that taken care of. I'd like to add that although it looks like im just throwing parts at it, this is all shit i have laying around so i might as well lol.

06-03-2015, 08:22 AM	#7
Thedriftbadger Zilvia Junkie Join Date: Jun 2013 Location: ontario Posts: 305 Trader Rating: (0) Feedback Score: 0 reviews	Knock sensor bypassed, runs absolutely perfect!