ignition systems

[jtracing]

i have a 1990 240 with the 91 ka24de motor and trans. my problem is its running real rich, i can see unburned gas coming out the exhaust and it gets on the rear bumper. it failed smog cuz it was running too rich and the rpms are too high, 800-1600 and sometimes up to 2000. my question is the guy who did the engine swap used the single cam ignition system, i know this cuz when i went to replace the cap and rotor i told the dude at pep boys it was the dohc motor and went to replace it and it was 2 different parts. since the dohc has 50 more hp i was thinking that i needed to upgrade to the dohc ignition so it would stop running so rich. i replaced the spark plugs with bosch platnum 2's and it has new ngk r8 plug wires. i was wondering what aftermarket ignitions are you guys running. the guy i bought the car from said the car was running a little lean. he put one of the air ratio meters in and it shows that sometimes it does run lean. does anybody know why? thanks for any help. later

[Tr0uble]

FYI A/F ratio gauges will give incorrect readings unless its wideband also it must have a data logger. The cheap 80 dollar gauges basically are rainbow gauges. Thats all they do is bounce back and forth.

Now a rich condition is caused by 1 of 2 things.Computers detects an increased amount of oxygen level flowing into the engine. The computer then tells the fuel injectors to dump more fuel into the chambers to try and get it to stoich (middleground between rich and lean if u didnt kno). If any one of the sensors are giving wrong data or no data this can cause fuel to be dumped into the cylinders. Or If the ecu is wrong then it cant properly translate the incoming data from the sensors resulting in a way rich or way lean condition.

Other thing that can cause it is a problem with fuel delivery. Leaking injectors can dump fuel without the computer knowing it. Bad/clogged fuel pressure regulator or disconnected or improperly installed fpr vacuum linecan cause fuel pressure to rise so high it forces excess fuel into the cylinders when the injectors open.Similar to opening a soda can sideways vs. shaking the can and then opening it sideways

Now with all that said....

Is it running stock ka24de ecu and not the ka24e?Maybe wrong ecu.If correct ecu then possibly incorrectly tuned ecu if chipped.

Got a check engine light on?Bad 0xygen Sensor maybe?Timing?Leaking Fuel injectors (internal leak)? or Aftermarket Injectors?Bad Fuel pressure regulator? or (fpr vacuum line leak?)Bad MAF sensor?

All off the top of my head that cause rich conditions

[jtracing]

i knew the a/f gauge was a pos. how would i know if he kept the stock single cam ecu or if he swapped in the dohc ecu. is there a way to tell? my check engine light goes on and off. the engine is stock, only intake. is there a way to check the fpr? i unplugged the maf and it wouldnt run and i was told if it does that its working, unless it has a falut. thanks for the advice.

[Tr0uble]

Off top of my head not much i can tell you on those 2 ecus as i'm a previous HonDoc... got into Nissans bout a year and a half ago. I can get back to you on that later if noone else knows. Takes time to research and i'm in middle of converting my fenders to s13.5 myself. The OEM metals ones. You can check your fuel pressure and see if its within specs that will let you kno if your fpr is working right. 240's dont have a schrader valve so you have to get s certain type of test equipment to check it out the pressure.Will be back on forums later tonight.

[jtracing]

a couple of weeks ago i had to get the gas out of my tank so i unhooked the fuel line after the fuel filter and it unpluged the main spark plug so the cap wouldnt get any spark(i cant think of what its called) and just cranked over the engine and put a 1 gallon jug there and let the gas flow into it. it didnt take to long. i had to buy the single cam cap and rotor when i changed them. i bought the dual cam one but it wouldnt fit and they were different parts. do you think that could also cause the unburnt fuel problem?

[Tr0uble]

I might be thinking of another car but isn't 1989-1991 sohc only?All dual cam ka motors are identical with a slight difference in automatic and 5 speed. Maybe you have a auto ecu? I switched out ecu in my car to get rid of the speed cut. But then again that still wouldnt cause that much fuel to be dumped as long as they were both dual cam ecus regardless if auto or manual. If you have a check engine light get the code. You might have a bad cam angle sensor. Search my reply to another guy's post about no spark. Bad cam angle sensor= repeated sparks+dumping fuel or no spark and no fuel. Try unplugging it and see if it stays the same. Also try unpluggin the O2 sensor. Just start unpluggin sensors 1 at a time. If you see a change plug it back in. Thats all i can tell you without having it in front of me.

[leper421]

Sounds like you got f*cked up the *ss by someone who didnt know what the hell they were doing... If you have a KA24DE, then EVERYTHING should be from a DE. If your engine doesnt look like the first of the following pictures(valve cover was painted black and green in this picture) then you dont have a DE.

http://www.scriptsandwich.com/...E.jpgh ... m/...s.jpg

I might be thinking of another car but isn't 1989-1991 sohc only?

89-90 is SOHC, 91-98 is DOHC

You might have a bad cam angle sensor. Search my reply to another guy's post about no spark. Bad cam angle sensor= repeated sparks+dumping fuel or no spark and no fuel.

There is no cam angle sensor. There is a crank angle sensor that is built into the distributor on the S13 KA24DE.

[jtracing]

its the de. it used to have an auto but the guy put the 5 speed in. he said he got the motor and transmission from the 91 240 and had them both rebuilt. so the motor and trany have about 15k miles on them. the engine feels real strong. thanks trouble, i'll start unplugging stuff and if i come across anything i'll let you know.

leper421, the pict with the 24 sticker, where is that supposed to be?also the ecu, does the ecu on the single cam look different? is there a different amount of pins on the ecu?

thanks for your guys help.

[leper421]

it used to have an auto but the guy put the 5 speed in. he said he got the motor and transmission from the 91 240 and had them both rebuilt.

leper421, the pict with the 24 sticker, where is that supposed to be?also the ecu, does the ecu on the single cam look different? is there a different amount of pins on the ecu?

The 24 sticker is on the front of the ecu. You'll find the ecu behind the passenger kick panel. Each version of the ecu gets a different number. 24 is the correct number for a 91 with a m/t (I dont think they changed it mid year, but I could be wrong). The 91 with an a/t has a different number. It is very possible that you have the automatic ecu that came with the engine. There are a few sensors that autos have that manuals dont and vice versa.

I highly doubt the E and DE pinouts are even close to being the same.

Can you take a picture of your distributer with the cap and rotor off, and a picture of the cap and rotor? Also get a picture of the electrical connector with the harness clip unplugged.

BTW, I have a **** load of spare parts for the s13 ka24de that I will soon be listing on here for sale (I just bought a Z). You can get first dibs. I have a spare distibutor and a 91 m/t ecu (the ones in the pictures).
Modified by leper421 at 8:19 PM 7/10/2007

[jtracing]

i looked at the ecu andit has a sticker that says 14. i can get a pict of the cap and rotor. i'd love to have first dibs on parts but im broke for now, thanks anyways.

[leper421]

I needed a break from my unpaid overtime work (I'm salaried), so I took the following pictures. If your distributor doesnt look like this, then its not a dohc distributor. If it does, and the cap and rotor dont look like this, then pepboys gave you the wrong parts. If everything looks right, then I dont know why you cant get things to fit...

http://www.scriptsandwich.com/240sx/ima ... ges/d6.jpg

[jtracing]

i unplugged the o2 sensor and nothing happened. what is suposed to happen. im gonna check my cap and rotor when my car cools down. since it never passed smog i never registered it so it has oct 06 tags. i decided to make my 240 a drift car and only track it. i dont have the cash to do engine swap so i want the car to be able to run as long as possible with out taking a dump on me. it just pisses me off that i didnt take the time to really check this car out before buying it. i would like to have it pass smog so i can make it my weekend warrior.

[leper421]

i looked at the ecu andit has a sticker that says 14. i can get a pict of the cap and rotor. i'd love to have first dibs on parts but im broke for now, thanks anyways.

http://jimwolftechnology.com/wolfpdf/ECU-ID.PDF

It doesnt list the two digit number (14, or 24), but does use the part number, in my case "A11-B44 G07" (see previous picture of 24 sticker).

It gonna be a week or two before I can inventory and take pictures of all my parts. I'm not looking to make much for the spare parts (most will be a loss, if you consider what I originally payed for them years ago). ECUs go for $150 from junk yards around here. I'd sell mine for $50, and I'd sell it for less if multiple parts are purchased.

[180fan]

did you try replacing the coolant temp sensor yet to resolve the rich condition? did you also inspect the o-rings on the injectors?

[jtracing]

where is the coolant temp sensor? i tried to take the injectors off but i wasnt sure on how to do it right so i didnt. do you just take the caps the screw on off and pull them out?

[180fan]

yeah the injectors have a tendency to do that. the screws and a long flat head should do the trick.

coolant temp sensor should be near the thermo housing.

[leper421]

where is the coolant temp sensor?

http://www.scriptsandwich.com/...1.jpgh ... m/...2.jpg

i tried to take the injectors off but i wasnt sure on how to do it right so i didnt. do you just take the caps the screw on off and pull them out?

yeah the injectors have a tendency to do that. the screws and a long flat head should do the trick.

That is how you remove a single injector, and I would only recommend this method for a dead injector, as it is very difficult to remove the injector without damaging it or breaking any plastic bits off. Any injector removed from the fuel rail will need a new upper and lower o-ring before being replaced.

If you want to check whether any injectors are leaking, the best way is to pull the entire fuel rail. Its a bit of work, especially the nut closest to the firewall. You need to remove the BPT valve assembly, and then need an extension or two, and a u-joint for your ratchet.

How does your distributor look compared to the my previous pictures? What year / model is your ecu?

[jtracing]

the sticker number on my 240 matches the one for the 89 sohc....A11-B04 G50 89 240SX N M C S13-KA24E 8.6:1 23710-42F01

stupid piece of ****

my cap and rotor match the ones in the pict. thanks for clearing that up for me.

man that pisses me off, the guy spent all that time and cash and still did a half *** job and cut corners. fu**** lazy people.

so im guessing the big reason why i failed smog was because the ecu is not right for the motor. how come it even runs as well as it does?

[leper421]

You'd better hope that sohc and dohc ecus have the same pinouts, because if they dont that means the idiot didnt replace the wire harness with dohc one.

[jtracing]

how would i check to see if he used the stock harness or the dohc one? just count the pins? by putting the dohc ecu in what kind of change in proformance should i see? it doesnt have alot of pull right now. i also have a 04 toyota corolla and i raced my wife and i was barley able to pull away from it, i did however beat a civic a while ago, just thought i would add that . as far as the harness goes, if he kept the sohc one and i buy a dohc ecu, what would happen, proformance wise? im dying to smog this thing so i can drive it around. i cant afford to make it "pass" right now.

[leper421]

You have a 90, with an 89 ecu, and 91 engine? wow...

If the harness connectors for the ecus are not the same between the sohc and dohc, then the guy did not replace the harness. That would mean that unless all the connectors to all the sensors are the same (highly doubt) then the guy cut and spliced the crap out of the harness to get it to work. Is there alot of electrical tape on the wires near the connectors for the sensors? Disconnect the harness plug from the ecu, does it look like my picture? I can get you a better pic if you need it.

If I recall correctly the 89s and early model 90s had an air temperature sensor mounted in the air box (sohc people, correct me if I'm wrong). The dohc doesnt have this. If the harness was swapped, the older ecu wont be getting this signal.

I know the 91 very well, and almost nothing about the sohc, so anything I say about the differences is only speculation on my part.

[jtracing]

it was made in 89 at the later end of the year so if i were to order parts for it i would need 89 year parts. the first year it was sold was in 90, so its a 90. its weird and stupid but thats how they do it, so i learned in college. yes there is tape around the ecu. as far as that sensor goes i have a short ram intake and there is a little sensor by the filter, small. i have no idea what it is or what it does.

[leper421]

it was made in 89 at the later end of the year so if i were to order parts for it i would need 89 year parts. the first year it was sold was in 90, so its a 90. its weird and stupid but thats how they do it, so i learned in college. yes there is tape around the ecu. as far as that sensor goes i have a short ram intake and there is a little sensor by the filter, small. i have no idea what it is or what it does.

Usually anything made in or after June or July is for the next model year. My 91 was made in 07/90. "so if i were to order parts for it i would need 89 year parts", no you would need parts for whatever model year your car is, most likely a 90.

I've said/asked it before, check that the harness connector to the ecu looks like my picture...

[Tr0uble]

There is no cam angle sensor. There is a crank angle sensor that is built into the distributor on the S13 KA24DE.

My bad if you check my post referring to another post of mine I had SR on the mind, lolz. Some how I forgot we was talking about KA.... i got ADD maybe? In that thread the guy tore the gear off that shaft.

[Tr0uble]

i unplugged the o2 sensor and nothing happened. what is suposed to happen. im gonna check my cap and rotor when my car cools down. since it never passed smog i never registered it so it has oct 06 tags. i decided to make my 240 a drift car and only track it. i dont have the cash to do engine swap so i want the car to be able to run as long as possible with out taking a dump on me. it just pisses me off that i didnt take the time to really check this car out before buying it. i would like to have it pass smog so i can make it my weekend warrior.

Here's some legal advice.If you bought the car in the same state that you live in and the car doesn't pass smog test, the guy you bought it from is liable for the cost to repair the car to pass a smog test. That's the law. So if you live in Cali and bought it in Cali then the guy has to pay the cost to fix it. I bought a car with a test pipe on it and failed. The guy had to buy me a cat and have it put on.

[Tr0uble]

did you try replacing the coolant temp sensor yet to resolve the rich condition? did you also inspect the o-rings on the injectors?

Bad or missing O-rings would mean fuel leaking from the fuel rail on to the ground correct? Not flood the engine.

[leper421]

Bad or missing O-rings would mean fuel leaking from the fuel rail on to the ground correct? Not flood the engine.

It depends on which o-rings are leaking. The upper rings would leak outside the engine, the lower rings would leak into the engine.