codyas92

My 1990 240sx has a Ka24de swap in it. I bought it from a guy less than a year ago. He sold is cause he couldnt figure out why is was running as rich as it does. Ive replaced the maf, ecu, temp sensor, cap and rotor, timing chain assy, checked fpr, checked and cleaned injectors, checked timing, compression tested, new head, now im in the process if replacing the engine harness. it runs nearly perfect when maf is unplugged in limp mode. Im stumped. Ive read all the posts of ka24de's running rich and none have helped. Anyone please help.

ska

check o2 sensor and fuel pressure.

Pro ViZIon

Also check the vacuum hose that goes to your fpr. Check fuel pressure at idle. With the vacuum hose plugged into the fpr fuel pressure should read around 34psi. With the vacuum hose unplugged from the fpr it should read around 43psi. If fuel pressure is high with the vacuum line hooked up then try replacing your fpr.

Oh and make sure your spark plugs are properly gapped.

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1990 Nissan 240SX w/KA24DE - New project
1984 Mazda RX-7 GSL-SE 13B

cotbu

check ecu for codes.

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codyas92

changed sensor along with half the engine :/ ill check the fpr and fp tomorrow

codyas92

unfortunalely for me, the guy before me didnt swap an obd2 harness when he did the 97 ka swap.

Pro ViZIon

That would only be to hook up a consult tool. you can still check for codes on the ecu. Search up how to do it.

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1990 Nissan 240SX w/KA24DE - New project
1984 Mazda RX-7 GSL-SE 13B

codyas92

will do, thanks.

ZenkiKid

If im right his consult port doesnt work anymore because he swapped in the dohc. The sohc to Dohc conversion results in eliminating the consult port

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cotbu

He can still pull codes. if the ka is obd2 he can hook up the obd2 port and it will give more info than the standard consult port. you are able to pull codes regardless of which system or port you have or don't have.

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codyas92

i did a search. the ecu needs the little screw to be set to diagnostics mode then the ignition on the on position. the check engine light will then do its own version of morris code using a sequence of long and short pauses between flashes. but i think the dash harness is from the sohc. will the engine light work the same as a dohc dash, my rpm and temp gauge doesnt work, everything else does if i remember correctly.

cotbu

The led on the ecu, if equipped will flash. The check engine light will flash if its wired up.
PS don't mean to side track you.

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codyas92

your not sidetracking at all. it all helps. thanks for everyone being so helpful. you all are getting me closer to figuring this out. theres not much else i can replace on the car. ive nearly replaced/checked everything lolits a money pit. im going to be checking the fp and fpr, aswell as the fuel pump if that is another potential cause.... could it be? i cant keep spending money on things that dont need fixing. i go to ptec for welding. so money is scarce.

Pro ViZIon

What did the ecu say?

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1990 Nissan 240SX w/KA24DE - New project
1984 Mazda RX-7 GSL-SE 13B

codyas92

im getting my car from the shop tomorrow. ill do the readout then. im putting my money on the fuel pressire regulator though. its a 97 engine and the harness i got was from a 97 kouki. the mechanic said the "harness is wrong.". i havent had a chance to check my self so i dont know why the harness wouldnt match. shouldnt pretty much all dohc ka harness be interchangeable? even if its an auto wouldnt the ecu and all the other stuff match up? the mechanic that had my car didnt check the fpr or the fp. he didnt even do a readout so im done with them and im doing it myself. since the fuel pressire regulator is mechanical wouldnt there only be a select few things that would cause a mechanically sound engine to run extremely rich?

codyas92

so i got my car back from the shop today. it runs 10 times worse. my air cleaner was not re mounted, my exhaust now leaks, some sort of mount under the intake is holding on by one bolt. the car is smoking way more, my brakes feel like air is in the lines and heres the grand finally. my car will not idle. it dies unless im giving it gas. i replaced the fpr today and it didnt make a difference. please help me. i just got really screwed. it seems like the running rich issue is getting worse over time. unburned gas and smoke is now comming from the before mentioned leak where the exhaust manifold bolts to the exhaust.

codyas92

tried to do a code readout. check engine light doesnt work. i also found that the two wires that plug into a small box that is screwed onto the battery terminal looks to be filled/covered in oil or mabey just wet somehow. the larger plug has a light brownish muck in it. the smaller one has dirt, rust, and oil inside it. could this cause it to run rich? please reply someone.

aznfab213

damn this car sounds like major trouble...

codyas92

yeah i know it is. mabey i should just run carbs and get rid of this efi shit all together.

AutechKouki

Bad o2 sensor could be the problem. disconnecting the MAF and putting your car into your "limp mode" puts the ecu in open loop. Could also be a short that's giving your ecu the wrong reading and therefore makes it run rich.
Either way it sounds like whoever did the swap did a botched job, and that shop you took it to should not even work on cars at all if you received it with missing bolts, obvious vacuum leaks and I don't even see how this could tie into your brakes??
And I would really advise you stop buying parts without diagnosing, you're just wasting your money.
Just my 2 cents

JDMRIDDAZ

coolant temp sensor
is the only sensor that will mae engine run like crap
20buks....
theres two water temp sensors
one wire...to gauges
two wire ...to ecu
two wire sensor if its bad will make engine run like crap
ur in clearwater if u were closer id come thru
but check the CTS

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codyas92

I can try another o2 sensor. a new one this time, but it doesnt seem like an o2 sensor can make a mechanically sound engine run this rich and all. im going to be getting another wiring harness to replace this nightmare thats currently in the car if that doesnt fix the problem at least its one more part thats not going to shit and would clean up the engine bay a little. your right, the guy that did the swap didnt do it right by no means. i have no clue why my brakes are so soft now. i dont get it. ill check all lines again to make sure vaccume is good. thanks for the imput, the mechanics told me these parts may need replaced. im going to be sending my car to hybrid motorsports to see if they can diagnose the problem.

codyas92

id like to hear more of this one wire. two wire you speak of. if i replaced my wiring harness would that get rid of any and all shorts of any wires in the car that could cause the car to run rich? they had to remove the intake manifold when they replaced the head. if there were an existing leak somewhere in the intake manifold and they made it worse could that make the car die out like i mentioned it was doing after i got my car back. i had to adjust the iacc to get it to stay alive. it still stalls out though. and i replaced the coolant temp sensor with a new one.

Nibras

get numbers , fuel pressure , air flow , compression , make sure everything is getting where it needs to be at the correct time, also check your ECU itself to make sure it isnt faulty, sometimes the ecu will send a signle from the maf to the o2 sensor causing a fuel mixture that is unwanted.

codyas92

im sending it to hybrid monday. ill have them check all that stuff then. ive tried 2 ecu's so thats ruled out.

codyas92

well i dropped my car off at hybrid motorsports. justin has been very helpful, hes went out of his way to get this sorted out. he did a code readout. it threw codes for the maf, the coolant temp sensor and the knock sensor. but it throws the code every few times. i was told the engine was from a 97 and i dont doubt that it is but its using 90-94 accessories. ive replaced the coolant temp sensor for a 97 and mabey the o2 sensor. could this cause some issues? also the harness i bought is useless since its off of a 97. could the distributor cause problems like this if it were bad? if anyone near largo florida needs work done on their car give justin at hybrid motorsports a call 727-753-9664. hes made more progress in two days than anyone has in the past two years.