91 KA24DE - auto to manual swap… using manual computer… ripped out auto comp… custom short ram is my only mod…
Carran fine for a few days then after the drive back from DX2 I started to have some problems…
Car bogs down to around 5000 rpm at wide open throttle…
I can rev to red-line (or anywhere else) but one I punch it to wide open throttle the car will bog down to 5000 rpm…
Same deal driving the car, runs decent around but just flooring it the car bogs down…
I’ve put in new cap, rotor, plugs and wires, checked timing (20 degrees btdc), injector are good and just ran some fuel cleaner, swapped the maf and o2, checked for vacuum leaks up top, checked electrical connections and grounds…
I’m not sure what’s going on… may 2 bad mafs??? I do have a K&N filter thats recently oiled and have red that the oil clogs (or destroys) the maf but what are the odds?
TPS sensor possible?
maybe cat clogged or another leak somewhere else?
damaged gaskets?
do I need 4th and 5th gear sensoer hooked up ?
Id say it is either the TPS or MAF.
Its most likely bogging because its not detecting that that alot of air is going into the pistons and the fuel mixture is too lean.
If you have a friend with a spare mafs, try getting that and testing.
Ive also heard of people cleaning out their throttle position sensor, check on freshalloy for zilvia forums, im sure someone has something posted.
Lastly, try cleaning the throttlebody, could be some dirt or something inside there clogging up the TPS.
it’s your speed sensors on the tranny.
the reason why the car bogs is because you’re hitting a certain speed, this used to happen in my first 240sx. Notice how it’ll bog at 5000rmps in lets say 3rd gear, but it’ll bog at 3500 or smth in 4th.
try it.
just took it for a spin… car bogs consistently around 5400 rpms in 1st, 2nd and 3rd… still could be speed sensor ??
also found a whistling noise after you get you let off the throttle on wide open throttle or sharp accelertaion… sounds like a blow off valve…
having traced it yet… need someone to help check… sound like its from the either down by the cat or behind the eninge…
maybe its the IACV… car isn’t idling very well… fluctuates +/- 100 rpms or so…
the car is running pretty hot, 2 notches from the top… just put in a thermostat and rad cap, running mostly water too. I’ll try cleaning out the rad its covered in feathers for some reason… :roll:
Your custom short ram may be fucking your MAF. I hear the MAF only works properly when the air flow is straightened through it. Too much turbulence will screw around with the measurement. The may be a problem. Also, check your fuel filter? Dunno…
if your maf looks clean, it should be OK. i thought it was my maf a couple times, once it was a bad plug, another time, it was this vertical cable that looked like the throttle cable. it was siezed and i lubed it up, freed it up, and no more bog. its located under the EGR, on the firewall (S14 model).
my car would bog at around 3500, and then rev right to the limit no prob.
it was this vertical cable that looked like the throttle cable. it was siezed and i lubed it up, freed it up, and no more bog. its located under the EGR, on the firewall (S14 model).
:?: I’m not sure what you’re talking about?
the Swirl Control Valve? it seems to actuate fine but there’s not “throttle”-like cable.
I tried running without the filter but I get the same effect.
injen intake on its way, swapping mafs with another 240 tommorow just to be sure
TPS, after reading the FAQ on 240sx.orgThrottle Position Sensor Adjustment
I get an odd resistance reading… its reversed?? :shock: ??
:!: tab up and using left and middle wires… I get about 10K ohms fully released and 2k ohms at wide open throttle
:!: while tab up and using right and middle wires I get 1.3K ohms fully realeased and 9.6K ohms at wide open…
Did the same for the blown k24 I pulled out…
On a good note though… I read a ground and proper 5 volts from the harnes and about .47 volts from the output (center wire) at idle…
Tried playing more with the timing didn’t get anything…
Did a compression test… about 175 accross the board…
checked the plugs… white blister marks so its definitely overheating bad… haynes manaul recommandation:
-over advanced ignition timing
-lean fuel mixture
-insufficient engine cooling
-lack of lubrication