Another bogging issue...

[DALAZ_68]

Fellow Zilvanians ... i need ur assistance and knowledge


heres my issue

Chassis: 1990 240sx
Engine: 1996 engine
problem: bogging out at 3k rpm under load (when in gear), not reving up smoothly

now be4 i get jumped at here is wut ive done so far to avoid asking this
Compression test: 190 190 190 178
airleak test: tight as a virgin
EGR: blocked off completely by ebay steel plate
TPS: good (borrowed from friends car) working TPS set at .5 at idle
Injectors: working properly, even used stethescope to hear em
Spark plugs: NGK V power ( ithink) were brand new now have blow by and whitish tip, which means running lean i believe
thermostat: new
plug wires: new NGK
Timing: Stock 20BTDC setting
fuel system: new filter,strainer, and pump FPR reads 40psi at idle
MAF: proper voltage and works great, borrowed from same car as TPS
Grounds: all properly bolted down
exaust: no black smoke or any kind that would indicate blown H gasket or coolant leak
Temp sensor: did FSM way of checking if it works ( dipping in boiling water with thermostat) and is functioning...
ECU: was only throwing EGR nothing else any body deduct anythign from this...ive gone to other forums and searched here aswell... worst case scenario id have to guess Knock sensor...whihc means ripping off intake mani...which i dont wanna have to do... anyother possibilities im more than willing to listen...

[RedtopTech]

just so you know, The EGR is there to cool down combustion temps in order to reduce oxides of nitrogen(NoX). It does this by flowing exhaust gas(duh) into the combustion chamber. exhaust gas being inert lowers combustion temps by taking up space and also reduces detonation.
Soooo the tick you described may be detonation but it is usually described as a coffee can full of rocks being shaken. Or you may simply have an exhaust leak causing the noise. Good luck!

[Antihero983]

is your IACV sticking? i'm having similar problems with my car (91 hatch with DOHC KA) and i had another tech here look at it and we've agreed it is most likely the IACV sticking.

[Z U L8R]

if that don't work just condemn the maf anyways cause it's funny lookin.

seriously though i've seen a couple maf problems because of the maf plug recently. you could always try to unplug your maf when it's doing it and see if nothing changed, then you know it's a bad connection if you've also tried your maf on your buddies car and not just his on your car. gl
Dave =]

[bo2o]

check vacumme lines. make shure there all capped and t'ed rite.
put ur plugs and check gap.
put more grounds.

[Z U L8R]

actually you know what....plug gap makes the most sense now that u mention it bo2o

bkr7e @ .028
bcpr7es @ .028
bcpr7eix @ .028

you won't have a problem with any of those, gl man
Dave =]

[DALAZ_68]

bo2o: like i said we did an air leak test...several actually one before removing the EGR and another 5 after just to make sure...and no air anywere...


ill try the plugs though... seeing as they look like crap i might aswell change em anyway....so gapping em to what 28......i thought they were soppose to be like 34-37


atleast that wat ''Z-net'' at autozone says lol, then again....it is autozone lol :duh:

ill give it a try

[MELLO*SOS]

Clear and repull the ECU codes... I was half expecting you to find a code 34 and have infamous KS subharness short. Symptoms sound identical; ECU retards spark timing from 3000 onward and the car feels dog slow.

Sounds like you've tried most of the basic fixes already... Might want to go back and double check them all over again in case something was missed =/

[DALAZ_68]

Clear and repull the ECU codes... I was half expecting you to find a code 34 and have infamous KS subharness short. Symptoms sound identical; ECU retards spark timing from 3000 onward and the car feels dog slow.

Sounds like you've tried most of the basic fixes already... Might want to go back and double check them all over again in case something was missed =/


that was my thought too...but it starts bogging round 2500

if i slam on the throttle, the car gets boggy doesnt respond for shit, in fact it looses revs, until the point i actually let go of the throttle, thats when it revs up...

my only solution is to only give it about 20% throttle

if i ease my way into it from idlle itll actually rev up pretty smothly until it hits say 4k it bogs out for a good 3 seconds then continues reving onward


-------------------------
my thoughts are if my dizzy is known to be good, and my wires all grounded...and everything is reading proper voltage and wut not... then maybe the KS is bad, re timing itself to i think 0 rite,

one of the mech said it could be a warpped head...but i dont hear any ticks, i did for a while but it was upper chain guide, ripped it out no more noise... i dont see any smoke from the engine bay...no discolored smoke from exaust... nada

[Z U L8R]

dalaz that's huuuuuuge hahaha. autozone says all nissans run a .044 gap LOL

your gap is exactly what your problem is
use either of the 3 plugs i mentioned above and gap them jokers to .028 and you're fixed =]
gj @ bo2o

i recommend the bkr7e's or the bcpr7es's over the iridiums, they're cheaper. the 3330's aka bcpr7es come pregapped to .030 you could probably pop those right in if you're running stock boost, but if you're running 14psi you should put em to .028.
gl
Dave =]

[DALAZ_68]

dalaz that's huuuuuuge hahaha. autozone says all nissans run a .044 gap LOL

your gap is exactly what your problem is
use either of the 3 plugs i mentioned above and gap them jokers to .028 and you're fixed =]
gj @ bo2o

i recommend the bkr7e's or the bcpr7es's over the iridiums, they're cheaper. the 3330's aka bcpr7es come pregapped to .030 you could probably pop those right in if you're running stock boost, but if you're running 14psi you should put em to .028.
gl
Dave =]


Bro...im running a s14 DOHC KA N/A

so should i still gap em to .28 ?

[Z U L8R]

OH WTF LOL i thought you had sr. ehhh, i think you run bkr5e's stock. in any case whatever you run stock, drop some new one's in there. don't use anything but the ngk oe recommended plugs and see how that goes. my fault

[DALAZ_68]

so then...what gap?? same .28?

[MELLO*SOS]

Wondering if u replaced the cap, rotor, plug wires lately?

GL I hate chasing down random shit problems like this.

[DALAZ_68]

Wondering if u replaced the cap, rotor, plug wires lately?

GL I hate chasing down random shit problems like this.

cap and rotor are good, NRK plugs and spark plugs are/wer new when swap was done

still need gap size when i get the sparkplugs though

[Z U L8R]

when you get the oe plugs you shouldn't have to gap em. just pop em in there

they should be .044 since autozone says every usdm nissan motor runs that gap.

[DALAZ_68]

44 it is then

[datsun510dude]

44 it is then




u ever fix this problem???????????????....im havin the exact same issue recently....i have done lots of research and have found the most common things to be the AIV, EGR, MAF or spark plugs.....

I replaced my plugs not too long ago....and put them in with a .044 gap as well..... checked all grounds and am throwing an EGR code.... 91 stock auto 240 with 170k on the clock.


thanks!

[DALAZ_68]

nah man i said fuck it and went CA18 on my rig lol

gl bro


pretty sure though might be a KS

[datsun510dude]

haha forreal? swapped the whole motor huh? Well, I have been reading A LOT and seems to be pointing to the KS or a short or possibly a combo of old plugs and a old fuel pump.....we will see....

thanks