re-doing MAF wires...help(yes, that means you r240na)

[gotta240]

I keep getting a CEL on my 96 240sx obd2 ka24de. No matter how many times i reset the ecu/clear codes it keeps coming back as MAF.

I have tried THREE different stock mafs and still get the CEL light for "faulty air/fuel metereing device". The wires are visibly worn and have cracks in them leading to the MAF. THE CAR RUNS FINE, but i'm wondering if the cracks are enough to throw a bad maf cel.

SO,

ONE- Am i correct in assuming its the wiring considering the car runs good and i've tried THREE MAF'S.

TWO- Suggestions on re-wiring please. I know the signals from the maf are based on resistance... therefore if i use the wrong type/length wire won't i get a faulty/innacurate reading? I'm good at soldering, so please give me advice... Also, where can i get the same pins that go into the maf plug, or should i just re-use the old ones... thanks and sorry for the essay

[drftwerks]

visual is first step to diagnosis. fix what you can see first, nissan might have the pins, use same guage wire.

[MELLO*SOS]

You might have a short in the wires to the MAF, try measuring each wires continuity with a DMM from the ECU to the sensor pin. Although i think if you had a short you would be in the 2500rpm safe mode.

[infinitexsound]

yep, measure the wires.... theres definetly a short... or just use one of those probe testers..

[projectRDM]

The MAF doesn't care about wire length or type. The only thing you need to make sure is the shielded signal lead is properly connected and the shield around it is grounded. I'd cut the plug off and back a few inches and start with a good plug. IIRC, the 98-01 Altima plug is the same, but don't quote me on that.

[NemeGuero]

Crimp the wires, don't solder. solder can wick down the wire and can vibrate loose.

Use a real crimper and crimp that shit.

[gotta240]

hmmm. interesting..

Thanks for the tip, i would have thought for sure solder would be best...guess i learned something.

I won't be able to source a new plug before friday night(when i need to leave for saturdays track event). I'm lost on the grounded shield. I looked and still don't quite know what you mean by that. Could i just cut back 6 inches or a foot into the maf wires and re-wire with similar guage right to the back of the plug?

thanks for your time

[drftwerks]

solder is best, do it right, and heat shrink

[NemeGuero]

Make sure its the legit crimps though.. not the tubed plastic cheap-o ones.

the kind MoTec sells for their wiring. Ballertastic.
http://www.motec.com/images/tooling.JPG


WAAYY better than solder.

Nobody uses solder on engine wiring harnesses. NOBODY.

Just the thermal expansion difference between copper and tin(solder) is enough to explain why you don't want it in there.

[gotta240]

sweet. where can i pick up said "baller" connectors? theres so much shit in that pic i don't even know which ones the connectors are...lol

[drftwerks]

ok

have fun

yay

[NemeGuero]

yeah, fastest pic I could find.

Umm.. dunno. Google it or call MoTec tech and ask them. They probably sell them.

AMP's crimp connectors

or any mil-spec crimp connectors

[drftwerks]

lol uhh yea if you say so, thats why when ther is a TSB from the factory for any car they say to stager and cut method and that they should be repaird with the proper solder and heat shrink method??? even for shielded wires. look up some of the procedures for the repairs, i can print some out for you, no problem.

ill save all you some time

http://www.markwilson.com/mustang_tsb/tsb05-18-07wire%20splice.pdf

ford factor TSB

[NemeGuero]

*sigh*

read.
http://fsae.com/eve/ubb.x/a/tpc/f/125607348/m/53010954411

As I said before... heat + vibration = solders worst nightmare.
But don't use shitty crimps.

If you use shitty crimps, you might as well just use shrink + solder.

T&N enterprise build and race formula atlantic series cars and they don't use solder.

GOOD crimps are factually better than any solder job.

[drftwerks]

good read, i appreciate it, still alot going for both sides, well what ever works. Esp for our apps.

[infinitexsound]

alot of that spacial race... connectors are GM style... just for ur info... and soldering wires is still in fashion...

[all stock]

that guy from UTA's fsae supports solder =p

why not just rewire the entire piece than crimp? fresh wire.

[ixfxi]

when repairing a circuit like joining wires together, go for solder. if you are using a specialty connector and have the crimp tool and prongs, then go for the crimping procedure.

for basic automotive repairs, both work really well. a good crimp tool is quite good. and in certain situations, solder is also good. both are very good techniques, it just depends on whether you need to repair or re-run new wires.

in the case of a mafs, just re-wire the entire damn thing. no sense in wasting time with shitty old wiring. i mean, 90% of the users on this forum have NO idea how fuckin dry rotted the wires are in their chassis. our cars are fuckin ancient history, the wiring is WAY past its lifetime.. especially the wiring around heat sources.

mike / clearcorners.com

[gotta240]

Great. Thanks for the replies guys. I"M GOING TO SOLDER. Just because i don't want to spend the 500 on a 20 dollar problem.

PLEASE HELP ME-

I don't know a DAMN THING about wiring...

1.Exactly what wire(guage and composition) do i need
2. what is with this "shielded" wire?
3. Can i re-use the pins in the maf plug or can i buy new ones somewhere? thanks!

[gotta240]

can anyone answer above q's? Need to buy the stuff and rewire it tomorrow night...thanks

[projectRDM]

Best bet, go find another plug on a car (like the Altima I mentioned earlier), and cut it back about 6-8 inches. Cut your plug off and go to town.

[gotta240]

ok, gotcha. Thanks again.

Can you quickly expain this "shield" that was spoken of earlier? Is it some type of shrink wrap or is it that 1 inch by two inch square thing that is about 5 inches in from the plug? Again, any help is appriciated as track day is in 24hours and counting down.

[ixfxi]

Great. Thanks for the replies guys. I"M GOING TO SOLDER. Just because i don't want to spend the 500 on a 20 dollar problem.

PLEASE HELP ME-

I don't know a DAMN THING about wiring...

1.Exactly what wire(guage and composition) do i need
2. what is with this "shielded" wire?
3. Can i re-use the pins in the maf plug or can i buy new ones somewhere? thanks!

the mafs wire is a low voltage sensative signal wire. like any signal wire, it should be shielded, this keeps the line clean from picking up noise/interference. the shield wire should be grounded to chassis.

do what russ said, get a better condition connector and cut some it off about a foot back.

[MELLO*SOS]

Can someone please link to appropriate shielded signal wire to use if recycling another harness is not an option? I find all kinds of UTX, GTX automotive wire, CAT6 ethernet, etc...

[DTS]

I had the same issue, it was a melted wire in the middle of the harness.

[gotta240]

ok, i just clipped another plug and am wiring it up now.

Everything is being solderded, shrunk wrapped, and covered in electrical tape.


HOWEVER- How do i take care of the shielded wire? Now that i cut it it isn't exactly "shielded"....suggestions? Tinfoil and tape!?!?! LOL. Seriously.

[sunnys14]

bump, i need to know this too. i am in the process of redoing my 3 maf wires.

[projectRDM]

The shielding doesn't matter that close to the plug. If you're splicing it in several inches away (18+) you would want to tie the shield in, but right near the plug you can leave it loose and just pull the remaining portion off.

If it is farther back, solder the wire together first, insulate, then wrap the shield together over that connection and solder again.

[sunnys14]

i am redoing the entire 3 maf wires, meaning i am only going to leave about 3 inches of the maf plug/wires left then i am going to use my own wires to run all the way back to the ecu. so do i need to find some shielded wire then? or will regular wire work?

[LB.Motoring]

Shielded.

Find a shitty harness and use it,

thats what I did to my Single KA harness

[gunluvS14]

I'm in the same boat, but I don't have time to go to junkyard and pull replacement plug out, where/who I can get a good working KA24DE pigtail?

btw, I repair/replace those 3 wires couple months back, I don't think i used shielded wire, and its mighty close to the distributor. That's pretty bad right?

I have the power cut/lost problem, and only happen when underhood temperature is really high (water temp close to 95C+), so what gives?

[iwishiwas-all*]

^^^^^^^^^^^^^ got the sameeee problem, and when i extended my wires for my sr i am positive i didnt shield it, i simply didnt have enough,
shit any way to get a aftermarket shield and how do i ground the damn thing then?