ka24de swap idles like crap. cant drive needs help( pros only)

[ShouldaHadaV8]

I put a 96 ka24de in my 92 hatchback, i have the original 92 wiring harness,exhaust manifold, distributor, and lower intake manifold/T.B.

the car doesnt want to adjust the idle right. At first i thought it because i used the 96 intake manifold, so i did the recomended s14 upper s13 lower intake manifold mix, this didn't work. so then i tried unplugging the TPS and adjusting the idle screw but it had no affect and it would idle high but bogg/ hesitate and stall. so i tried to tighten the throttle cable but it just wasn't right. so the i replaced the TPS, coolant temp senor, o2 sensor ,and spark plugs. it fixed the high idle but it still just doesn't adjust right. after about a minute you can ease on the gas but it hesitates. the MAF seems to work , when unplug it it drops RPMS atleast, and i would think the iacv works even though the screw doesn't affect it, it does idle descent at times but bogging becomes the problem. Im going to replace the knock sensor next, what else would cause this unstable idle?

I have wierd wiring issues i've noticed may be causing this. my harness has been "altered" by one of its previous owners and its does a few things like: if i leave the battery cables on over night my battery dies, i dont get power to my distributer using the green relays i have to jump it with speaker wire, my speedometer/rev/temp gauges worked befor the swap ( green and black wires got cut and re-saudered ) but thats a whole new ball park.

[Roger_cha]

well first off check for you vac leaks then check if you hook up the wiring right and what ecu you are using. for the wiring check the FSM for more details since you said that your wiring harness has been altered.

here is the manual.http://www.240edge.com/manuals/s13-ka24de.html

[ShouldaHadaV8]

Yeah, i thought the same thing for a while about the vacuum leaks but i went over that sh-t for about a month straight. and the ecu and all its parts are the original from the 92( ecu, harness, distributor,etc etc). so i dunno

[Roger_cha]

does the engine bogs when you try to rev it and does it go pass 3k rpm, if it does then your maf is bad but if it dont then it might be your iacv. you can try replacing the iacv with a known good one and see if that helps.

[ShouldaHadaV8]

it will go past 3k but i have to ease on the gas if i give it to much pedal too fast it boggs or hesitates. i will go buy the new MAF first, but i did notice that it drops rpms when i unplug it though so does that mean its working or does that not really mean anything besides i unpluged it.

either way im gonna replace the maf, knock sensor, bigger fuel pump, wiring harness, and hell if i need the IACV gotta buy that too.

[ShouldaHadaV8]

wow i went to go buy the maf and knock sensors today. i didn't know they were so expensive.MAF sensor:$200-300Knock sensor:$100-150i didn't buy either one of them, im gonna try to clean out the maf first.

[lbreevesii]

Just grab the maf from the junkyard as a spare. There are however basic tests for the maf outlined in the FSM.

For the knock sensor, go to ebay. 25 bucks.

[kouki-guy]

get a new harness imho, a butchered harness will always be a butchered harness.

as for the high idle, i can guarantee that whoever messed with your harness messed up the ground connections as well.

if you don't do anything, at least check your grounding points!

[ShouldaHadaV8]

yeah im just gonna buy a new harness because i wont be able to rule out any electrical problems untill know the harness actually is functioning and grounded right. i also bought some MAF cleaner , so if cleaning it and the IACV doesnt work it will be a new harness soon. but what bothers me is i have had other motors on this same harness and it worked fine i just couldnt get it to stop draining the battery. so i wonder if its not a grounding issue making the car idle weird do I NEED a new IACV, MAF, or maybe a bigger fuel pump or what exactly it is , I kind of have to rule out everything one by one because im not sure what it is. i know its just one thing causing this problem and i have enough money to fix it, but im running out of money quick and buying things that dont work is just not an option. i got about $750-800 left to get this thing running.

[Second Shadow]

i just couldnt get it to stop draining the battery.

if this is only happening with the battery hooked up, there is no way your wiring is correct. if you have a short to ground, or even like a low resistance path that drains the battery overnight, any number of things could be screwing up.

your car needs to have a 12V source and it needs a solid ground an anything thats making them even close to being the same point electrically is going to cause problems. I'd look at your harness, find where it's been modified, then check wiring schematics, and if you can find any discrepancies.

realistically I don't think you can even check things like the maf if that's going on, I don't see how they could give accurate readings even if they're perfectly fine.

[pawpaw18_00]

Check dist. timing could be off a tooth.

[ShouldaHadaV8]

if this is only happening with the battery hooked up, there is no way your wiring is correct. if you have a short to ground, or even like a low resistance path that drains the battery overnight, any number of things could be screwing up.

your car needs to have a 12V source and it needs a solid ground an anything thats making them even close to being the same point electrically is going to cause problems. I'd look at your harness, find where it's been modified, then check wiring schematics, and if you can find any discrepancies.

realistically I don't think you can even check things like the maf if that's going on, I don't see how they could give accurate readings even if they're perfectly fine.

yeah i completly agree because nothing i check with a multimeter is where it is supposed to be and im having to jump relays with speaker wire. i honestly do think im going to have to replace the harness befor i can assume anything.

[ShouldaHadaV8]

its pretty hard to find a new harness for sale. does anybody know where to buy cheap oem wiring harnesses for these 240sx's besides at a junkyard

[ShouldaHadaV8]

alright i bought a new harness in really good condition. it said it was for a 91-93 ka24de 5 speed, i was wondering if there is any discrepancies i need to know about with the year differeces, to make sure its going to plug-in and work "RIGHT". any tips etc,etc, theres not too much more things i can think of after this that would cause bad idle besides maybe a new bigger fuel pump, or a new IACV. i cleaned the maf it should be fine "i think"

[ShouldaHadaV8]

do all 91-94 ka24de 5speed wiring harnesses work with each other or am i going to have to do anything to make it work.

[ShouldaHadaV8]

now that ive got the new harness i have a prediction that its not going to fix my problem, i noticed that since im jumping the green relays with speaker wire i've most likely got a problem with my lower harness or my transmission harness they are more closley related to my battery which keeps draining for no reason, which means i've got to find either the lower harnesses for cheap or buy a parts car and rob the s*** out of it. this sucks c*** 4 sho, i prolly could have bought another running 240sx for the price im paying to fix this ones problems.

[fleali88]

i had a similar issue in my 97 240 ka24de, and it was caused by the alternator plug wasnt "clicked" in all the way, as soon as i did that everything came back to normal........for a while lol, now my fuel pump is going out and i need a new o2,maf, and ect sensor, but no matter, ive got my s14 sr waiting in my shed

[ShouldaHadaV8]

could a bad alternator be my problem, i didnt think that was the problem but do these syptoms happen when its bad, i didnt notice the battery draining while its running ,only when i leave the terminals connected to the battery for a long time.

i need to find someone who knows a thing or two about wiring.

[ShouldaHadaV8]

got the new engine harness on, im going to jump the car off and try to see if it helped the idle any, i will also be able to see if the battery is still draining. i hope this works

[ShouldaHadaV8]

NOPE!
still have to jump relays so i know its still fu-ked, i did an ohm test from the green ign. coil relays to the distributer and got 8.65. i think i either have to replace the lower harness or find a wiring specialist.

it stills starts and seems to try to idle pretty good for a few seconds then it starts to bogg if i touch to the gas.

any thing that causes these problem i need to know. maybe then i could do a checklist i know this is something very simple.

[ShouldaHadaV8]

i think i may have pinched the harness which runs above the radiator and behind the headlights when i had to rock the new motor in. regardless im going to go over everything electrical which is causing my little problems: brattery draining, jumping relays(ign. coil), speedometer/rev./gas gauge not working anymore, AND i noticed my fuel pump only works when i turn the cannon plug a certain way?????? maybe i need to replace the speed sensor as well i but dont see it just going out when it was working already but hell i am missing a few transmission senors.

[shiro_neko]

if your car ran fine while accelerating gently and hesitates when you accelerate hard you might have some grounding problems. and this makes sense because you recently swapped the engine. read this zerothread/159907

You can have a high idle if one of your components are giving a wrong signal. check your TPS if its giving the right signal http://www.240sx.org/faq/articles/throt ... djustm.htm and turn your ECU screw all the way counter-clockwise (if your ECU screw has an idle adjust, the s13 does)

if your idle is still too high or is bogging down, adjust your idle adjust screw with TPS disconnected. if adjusting this screw does nothing check your neutral switch if its connected. check the switch (disconnect the harness). there should be continuity while in neutral. no continuity when in gear.

and what was the last thing you did before the gauges went out?

[ShouldaHadaV8]

well i went to the previous owner of the cars house yesterday and drank some beers and played horseshoes, so i got to ask him a few questions about the car and how it ran he said the gauges would flicker on and off every once in a while ,mostly off. but he said it didnt have trouble with idle. i did a ground test with my voltmeter and got right under 2 ohms on the body ground by the battery. and i have tried to adjust the idle all sorts of different ways which were not sucessfull, which i believe is because of bad wiring, nothing seemed to ohm right. an

where is the neutral switch? and where is this ECU screw

[ShouldaHadaV8]

i dont think there is a neutral switch on the 5 speeds, and i haven't seen any idle adjust screw on the ECU. but i could be wrong.
i noticed to get the car to start i have to barely touch the gas, but once its starts if i give it any more gas it just boggs down and tries to stall. i want to know everything that can cause this? im getting pretty pissed off at having a car that runs but cant drive

[shiro_neko]

The idle adjust screw in the ecu is the screw to turn to set ECU modes. In the SOHC ecu its ha an idle adjust label on it. might be different for the DOHC.

Its taking a long time to upload some pics. you can check EL-202 of fsm to take a quick look. the neutral switch is for m/t. the a/t uses inhibitor switch. in the dohc the sensors in the transmission is as follows: (starting from nearest to engine) backup lamp switch, neutral switch, and 5th position switch. next would be the speed sensor then rear heated o2 sensor which are farther apart from the 1st 3 sensors.

check your timing and ignition wires. also remove the exhaust gas sensor harness and try to drive

edit:
pics up


oh and for the gauges. check you fusible links and fuses. I'm not used with the DOHC FSM so I cant trace the wiring for the ignition coil yet.

[shiro_neko]

and 1 more thing. when my gauges stopped working. 1 of the metal plates (are these diodes?) behind the gauge cluster lost continuity causing the gauges to stop working. the electrician just soldered a jumper wire (1 strand of a wire) between them. you can try probing the back of your cluster for continuity.

[ShouldaHadaV8]

See although the wiring may be f_cked, I just want it to quit boging, i dont need a speedometer. i know this is easy to fix i just have to find out what is causing the bogging ( this is the only reason i dont try to drive it yet) or what is causing the draining battery, i have so many weird wiring issues, i dont know if any of my sensors are capable of properly functioning, but then again all i did was change the motor and it worked before.

not to mention i cant search s*** with NICOs new software.
I just want to drive my car for the first time.

[shiro_neko]

well if your sensors wont work properly then your ECU will receive wrong signals which will cause bogging and irregular idle. try one of these steps to check some components. its easy to do.warm up your car until temp gauge is in the middle. but since yours doesnt work, running it for 10-15min might be enough.

remove your aac harness from iacv and see how it behaves. try to adjust idle through the idle adjust screw with tps disconnected.

remove the vacuum hose from fuel pressure regulator. improved, check fuel pressure. apply vacuum to fuel pressure regulator. improved, check mixture ratio.

disconnect your exhaust gas sensor connector. improved, check exhaust gas sensor or circuit.

make sure your engine temp sensor works.

your replacement engine might have components that needs cleaning, setting up or replacing or the ECu is just not getting signals from them. which will be a lot of work tracing these but its pretty much straightforward.

[shiro_neko]

I read your other post in the nissan tech forum which is more descriptive and its not an idle problem that you're having. I really dont know much about the DOHC but this is how I understood the schematics of its wiring diagram. lets troubleshoot the wiring issue first as this might be causing your bogging.

check your ignition switch harness. your ignition switch gets it power from the battery through the white wire (terminal 1, top left). when ignition key is turned to "ACC" the white wire and white with blue stripe (terminal 2, lower middle) gets continuity. which the white w/ blue stripe, after getting voltage, will turn on your accessory relay which gives power to some of your accessories. so when the key is turned to "OFF" there shouldn't be power passing through. so probe the white w/ blue stripe. the black with red stripe (terminal 3, upper middle) turns on your ignition relay 1 and another white wire (terminal 4, lower middle, beside the white w/ blue stripe) turns on ignition relay 2 when key is turned to "ON"

[ShouldaHadaV8]

Hmmmmm......im going to have to look at this for any problems. I also noticed today when i REALLY looked at my main battery ground which runs to the battery tray, and then to the intake mani. ground. where the wire meets the battery tray its grounded to nothing but rusted chunks of rust. so i may just need to reground everything even if it doesnt change the problems with the relays and the draining battery, etc...... it may be able to hold idle. we will see

as for trying to unplug the aac and adjust the screw, the screw doesnt do anything, which you said was because i didnt have a neutral switch.