Before i take it to the shop... or drive it in a lake...

ONLY for ADVANCED technical discussion about the 240sx!
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BlackZenki82
Posts: 1140
Joined: Wed Aug 06, 2008 5:02 pm
Car: 1991 Nissan Skyline GTR

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took the S14 and it's SR out for it's first road day since the swap (only minor up and down road trips)... and didn't make it home.... drove into work just fine, lunch break boostin'... then on the way home... it's starts bucking, and bogging... OH NOES... home is 18 miles away, interstate... i have no idea what the prob is... but here's the symptoms if anyone can help me figure it out...

power steering hose, one of em, exploded the other day... that was fun, anyways, it prob sprayed all over the filter, and numerous other things...... this is just some background info that might be helpful...

okay... driving down the road, it's like I'm hitting a fuel cut randomly... missing or something, idle is rough, and sometimes smooth, then give it gas, and it acts like it's missing.. car runs and drives, cranks up like normal, but has those symptoms... now, it's a bit more aggressive than it sounds... as if my motor is dieing as I'm driving, but then comes back, dies, comes back stays smooth, then bucks/bogs...

i removed the air filter, thinking it may be clogged with PS fluid, and the engine acted like it wanted to die... then idled back up to normal...put the filter on and it surged...

during normal driving, the -hG should be around -10ish, give or take load... while cruising now, it sits at -21 and between -13 and -15 @ idle....

I'm leaning towards faulty MAF, but the ECU isn't throwing any trouble codes... I'm going to try and solve the problem with my 600CC injectors and Z32 MAF.. maybe that will help, i don't know....

it sucks having my baby parked in a wal mart parking lot over night... this will be the second night she'll be there... i may try to nurse her home, but I'm afraid of causing more damage...

could a stuck/seized turbo cause a problem like this? it has been making a funny noise from what sounds like inside the unit while boosting (rattle whistle is the best i can explain), and is getting laggy... and it's a low end built turbo...

CAS maybe? injectors?

sorry for the long post, but i try to be as detailed as possible for you guys....


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Wc240
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Joined: Tue May 12, 2009 8:58 pm
Car: 89 Nissan 240SX
97 Nissan 200SX
91 Nissan 240SX ka-t
06 Scion xB
2000 Nissan Frontier
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try cleaning the maf with rubbing alcohol and a q-tip. be gentle

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BlackZenki82
Posts: 1140
Joined: Wed Aug 06, 2008 5:02 pm
Car: 1991 Nissan Skyline GTR

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so get this.... i go to start my car, to back it out of the spot i pulled into, and a ton of smoke came out of the engine bay... so i cut the car off and joked with the tow truck driver "no better place for a engine fire than right here in the parking lot of the fire Dept"... popped the hood and low and behold.... smoke POURING out from under the coil pack cover... i get hte car home, pull the cover and the plug to Cyl#1 is fused and melted to the coil pack...

luckily enough, i had a spare harness, and coil pack, i install them, and motor came to life, sounded good for 3 seconds then dropped to like 400 RPM and sounded like it was firing on 2 cyls...

i'm still thinking at this point of buying a new OEM S13 SR harness, and sending it to Taylor Durdan to convert it to S14, PREOFESSIONALLY.... i thought i did a good job... appearantly not....

here's what i've done so far...

no smoke from exhaust

MAF cleaned

TPS @ .51v (i know, supposed to be .45v, but still within .45-.52 range)

smells like a 2 cycle... rich as hell, but wideband reads LEAN.. and i mean --- no reading lean..

i'll have to do a vac/boost test soon, but I'm pretty sure that's not the problem...

coolant temp sensor has been replaced...

coil pack replaced

coil pack harness replaced

constantly checking codes- all clear (weird i know)

any other input other than boost leak test? i'm thinking harness..... but at least the car is at my house now.... nice and safe!

rb25det250sx
Posts: 443
Joined: Sat Feb 07, 2009 9:20 pm
Car: '96 Nissan 240SX RB25DET powered!!!
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sounds like your not gettin enought fuel.. check the fuel filter. injectors, make sure the rings didnt get tore and there leaking. take the plugs out and crank over a few times after that, and try again.

Bongpain
Posts: 89
Joined: Tue Feb 01, 2005 3:53 pm
Car: 92 240sx

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BlackZenki82 wrote:smells like a 2 cycle... rich as hell, but wideband reads LEAN.. and i mean --- no reading lean..
let step back. SMELL RICH. so make sure you are firing in all cylinders. then i would pulled back the tape to cylinder #1 coil and follow as far back as possible. WHY? you ask. your coil melted. and what can cause this a possible open wires the make contact with each other after the vibration from the engine running for 3sec and ground out causing an ARC and weld your coil. I KNOW THIS SOUND STUPID. but sometime you just have to look out side the box.


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