View Full Version : knock knock
theianmcdougall
09-16-2008, 04:53 PM
well im still having problems getting my newly swapped redtop sr20det to run right
it driveable but doesnt want to rev past 3
is running rich
and after i drive it a while it idles crappy
recently i check my codes on the ecu which read a 12 and 34
i believe those are my MAF and knock sensor
ive checked the maf, and its good
it even came off a sr20det that i know for a fact ran right
so should my problems be solved if a just get a new knock senor?
and if so does anybody have one have works well?
-thanks
96Turbo
09-16-2008, 05:06 PM
i'm betting ur MAF wiring is wrong....that's what was wrong with mine...although it didn't throw a code. I forgot to insulate 2 wires and it threw everything off.
so, check wiring, and definitely replace knock sensor if you want full power
theianmcdougall
09-16-2008, 06:08 PM
how does not insulating wires make it run like crap
and which wires do i insulate
Massimo Power
09-16-2008, 06:48 PM
they could touch eachother and causes shorts which means wrong readings coming from the maf
theianmcdougall
09-16-2008, 08:01 PM
true but i looked at it a couple times and i didnt see any wires touching each other
burnsauto
09-16-2008, 08:23 PM
basically...nissan insulates it, you should.
theianmcdougall
09-16-2008, 08:38 PM
yea
quick random question
is the knock sensor on the lower harness with the starter and altinator and all that?
96Turbo
09-16-2008, 08:49 PM
ok....i think some of u are confusing insulating with shielding. nissan uses shielded wire for the signal wires for the MAF. you probably had to extend it like i did (rhd harness into lhd car). when you extend it, just chop off a piece of shielded wire from your old KA harness...or buy some.
but inside this shielded wire is 2 wires. what i did was not tape up those 2 wires when i soldered them. just make sure that ur wires are all insulated, and that they don't touch any of the shielding strands.
and im pretty sure the knock sensor harness is tied into the lower harness on the sr (it is on the RB). Just dissect the lower harness and detach the knock sensor harness. you don't need it to be tied up with the lower harness (it isn't connected to anything on the lower, it's just all taped up and loomed together) plug it into ur main engine harness and secure it. dig?
96Turbo
09-16-2008, 08:50 PM
did you extend the MAF wiring? if so i'm betting you made an error. If it's all stock, then just inspect it
SidewayZ-s14
09-16-2008, 08:56 PM
Had the same EXACT problem as you're experiencing.
I needed a new fuel pump. It did the trick :]
GoodLuck!
theianmcdougall
09-16-2008, 09:01 PM
yea me and a friend extended the maf wires (and he has succesfully done like 3 sr swaps)
but ill go back over them and try to do what you said. I just dont get how if it was wired wrong or getting a short it would work at all
yea thats what i thought, because some of the wires got cut on the lower harness and im betting the wire to the knock sensor isn't even connected
anyone kno what color the knock sensor wire is on the ka so i can make sure there connected
96Turbo
09-16-2008, 09:41 PM
the engine will run with no maf connected at all.....but not smoothly or correctly
i consider myself good with electrical and wiring stuff, but it's easy to make little mistakes that cause big problems. Just a small stupid mistake like not taping up the maf wires
the knock sensor wires on my rb (nissan tends to use the same wiring color conventions) were clear. It's like a gold/yellow wire with clear insulation
and sidewayz has a good point, i've heard of ppl with bad fuel pumps having similar issues. but since u know for a fact ur throwing a knock and maf code, take care of those first. but i'm pretty sure u should have a walbro for an sr swap
theianmcdougall
09-16-2008, 09:48 PM
yea
and hes wrong
i installed a walbro 225
im running wayyy to rich for a fuel pump problem anyways
especially when im shooting 2 foot backfire flames
Addicted2Kouki
09-16-2008, 10:01 PM
yea
and hes wrong
i installed a walbro 225
im running wayyy to rich for a fuel pump problem anyways
especially when im shooting 2 foot backfire flames
running rich and only revving to 3k = maf/maf wiring. no question about it.
theianmcdougall
09-16-2008, 10:14 PM
theres only 3 wires
and i extended them
would it even work if the the wires are going to the right place
or is it a bad connection or a short?
96Turbo
09-16-2008, 10:33 PM
you tell me! It will definitely work even if your wires are messed up.
when i was diagnosing my maf wiring problem a guy told me he started up his engine without a fuckin intake manifold on it!!!
yes, 3 wires. One is a ground, and the other two are inside a shielded casing. peel all that shit back to reveal the wires within. Just check where you spliced on your extension. I have a feeling u'll find something is awry
yea...i just said awry
theianmcdougall
09-16-2008, 11:05 PM
haha will do
hopefully i will find something awry
if i do find something and wire it right, will it work right
or is the knock sensor gunna still throw it off
96Turbo
09-16-2008, 11:54 PM
it will be waaaaaaaaaaaaaaay better. you'll no longer be limited at 3k and it will run and drive pretty much perfectly.
this is funny cuz you're having basically the same problems that i had with my swap. once i fixed my maf i busted a knock sensor fixing my intake manifold.
you will think the car is perfect, but the ecu will be pulling timing due to the faulty knock circuit. retarded timing=retarted engine
you'll probably be getting about 70% of full power. at least that's what i would guess i'm getting from mine.
renegade_ewok
09-17-2008, 12:09 AM
how does not insulating wires make it run like crap
and which wires do i insulate
My car was wired like absolute garbage and nothing was connected right. When I turned on the highbeams I would backfire and shoot a flame. Previous owner couldn't wire shit.
Its pretty easy hah
96Turbo
09-17-2008, 01:08 AM
^^^lol that's realy funny
hope u got that figured out tho
theianmcdougall
09-17-2008, 12:41 PM
My car was wired like absolute garbage and nothing was connected right. When I turned on the highbeams I would backfire and shoot a flame. Previous owner couldn't wire shit.
Its pretty easy hah
haha thats awesome, i wanna kno excatly how to wire that one
96Turbo
09-17-2008, 12:44 PM
^^^get it sorted out yet?
theianmcdougall
09-17-2008, 01:55 PM
nah my car is about an hour away at my parents house
im just trying to figure it out so i can fix it and bring it to my apartment
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