dropping resistor where abouts?>

[dsilvia89]

hey guys i am having problems with my engine, it wont start. i have read alot of forums and now i am thinking maybe my dropping resistor? is the prpblem

what i need to know is what it looks like and WHERE it is located??? i have a ca18det in my 1989 nissan silvia. (previous engine was the ca18de)

thanks alot for any help i get!

[boost_boy]

You are looking for a rectangular-shaped aluminum-colored box that has an extension with a grey connector attached to it. It's probably around 4-6inches and it should be attached to your engine harness somewehere. If you just did the swap and don't see, then this would be your problem if your car was wired correctly in the first place. If your car stopped running on you then something else is probably at fault.

[D_Stirls]

Did you swap the looms when you did the engine conversion?

The reason i ask is because CA18DE's run high impedance injectors and therefore don't run a Dropping Resistor. So if you didn't swap the looms you won't find the resistor because there isn't one.
If you have the CA18det injectors without a dropping resistor you run the risk of blowing your injector drivers (if you haven't already).

[dsilvia89]

k... dont beak...please, but i dont even know what a loom is.

could you pls also educate me on the loom, as well as what i need to get my engine running again..its been tooo long!

when i did the swap, i used the det ignitor chip, ecu, harness (that was still attatched the to the engine), and maf.

i have not had this engine running at all yet so hopefully i didnt blow the injector drivers? (also dont know what that is )

[D_Stirls]

Loom = Harness

The dropping resistor should be in the front Left Hand Corner of the engine bay (well it is on the JDM S-Series cars anyway).
And it looks like this; I think this one is an RB one but they look identical it only the amount of wires that will differ from the one pictured.

There are two resistors if you car is/was and Auto but the auto resistor only has a couple wires where are the injector resistor has more.

[dsilvia89]

so since i used the harness that came with the engine, this means the loom was changed?

a loom is a harness? thats all? (just for clarification)

i am not able to go look at my car tonight, but i will check tmr for sure.

i am almost certain that i do not have one of these dropping resistors because i dont recognize that item at all, and i mean i did the swap and worked on it for hours, it is recognizable. sooo... what to do? (once i know for sure i do/dont have a dropping resistor

also, the car is a 5 speed transmission. i am not able to say if it was ever an automatic. i hope not :P is there any distinctable things i can do, or look for to find out weather it
was an automatic at some point in time.

[boost_boy]

so since i used the harness that came with the engine, this means the loom was changed?

a loom is a harness? thats all? (just for clarification)

i am not able to go look at my car tonight, but i will check tmr for sure.

i am almost certain that i do not have one of these dropping resistors because i dont recognize that item at all, and i mean i did the swap and worked on it for hours, it is recognizable. sooo... what to do? (once i know for sure i do/dont have a dropping resistor

also, the car is a 5 speed transmission. i am not able to say if it was ever an automatic. i hope not :P is there any distinctable things i can do, or look for to find out weather it
was an automatic at some point in time.

Make sure that you are indeed without a dropping resistor and if so, I think I have an extra one that can serve your car better as I don't use them on my set-ups. And 'YES' a loom is a harness as the dropping resistor is also called an injector resistor as well.

[dsilvia89]

i am for sure without a dropping resistor.

there is a clip that looks like it could be plugged into the image above. looks like a perfect fit. and where that is coming off the harness about the same place my MAF
sensor clip is.

i need some information on how to hook this dropping resistor up, as i didnt even know it existed till a couple days ago :P

also, boost_boy could you give me information on the injector drivers? you mentioned the resitor could be my problem and result in the injector drivers failing.
i would just like to know where these are, what they look like and what to look for if these have resulted in wrecking also. thank you guys sooo much

[boost_boy]

i am for sure without a dropping resistor.

there is a clip that looks like it could be plugged into the image above. looks like a perfect fit. and where that is coming off the harness about the same place my MAF
sensor clip is.

i need some information on how to hook this dropping resistor up, as i didnt even know it existed till a couple days ago :P

also, boost_boy could you give me information on the injector drivers? you mentioned the resitor could be my problem and result in the injector drivers failing.
i would just like to know where these are, what they look like and what to look for if these have resulted in wrecking also. thank you guys sooo much

The injector resistor is a plug and play application. It's not complicated, but you will need one. As for the injector drivers, they are in the ecu and I really won't worry about ecu damage just yet (seriously doubt it), but I hope your wiring is correct or there could be more issues later. Again, you'll need to acquire an injector resistor, plug attach it to your harness and see what happens.

[dsilvia89]

thank you so much. ill let you know once i get one and put it on, thanks!

[D_Stirls]

You won't have any ECU (injector driver) damage because with no dropping resistor plugged in there will be no current drawn as your injectors wouldn't be firing at all.
Once you plug in the dropping resistor providing there is no other wiring issue you should be up and running.

[dsilvia89]

thank you for confirming that, i am excited to find this resistor and try it out. as far as the wiring, everything seems to be correct, although there is one blue n white wire that is not connected to anything, its just loose, coming from the engine harness(not the connector side) and i dont know if this is fishy or not but there is also 3 blue n white wires spliced together. im not sure if this is going to pose a problem or not, i have no clue. but thanks!!

[blownhemi]

You won't have any ECU (injector driver) damage because with no dropping resistor plugged in there will be no current drawn as your injectors wouldn't be firing at all.
Once you plug in the dropping resistor providing there is no other wiring issue you should be up and running.

On the contrary, injectors will fire, and they will draw more amps, because the resistance of the injector circuit is about half without the dropping resistors (I=U/R). But still, that should only be a problem if your ran it like that for a long time, and on a high duty cycle (high RPM with high load), so that there was enough heat buildup to damage something. If yours didn't even start, as everyone said you should be good after plugging them in.

The dropping resistor pack is attached by two screws to the air filter housing on the S13 CA18DET, btw.

You can also make these resistors yourself, you only need 4 pieces of about 6,3ohm 10W ceramic resistors, and solder them into a star connection. But unless you're really comfortable with soldering, you are better off just buying a stock one off boost_boy.

[D_Stirls]

With the resistor not plugged in then there will be no circuit created. It's a DET loom so the injector circuit goes through the resistor plug. Without the resistor being plugged in there is no circuit.

[blownhemi]

With the resistor not plugged in then there will be no circuit created. It's a DET loom so the injector circuit goes through the resistor plug. Without the resistor being plugged in there is no circuit.

Oops, that's true. I got it mixed up in my head with a honda I worked on last week, which had a short circuit plug in place of the dropping resistor plug....

[dsilvia89]

no worries man...

still looking for the part

[dsilvia89]

i live in alberta, and i cannot find this part anywhere, ive searched up and down. does anyone know a website? where to find one?

[dsilvia89]

boost_boy or anyone else with good nissan knowledge....

i got my part in the mail today...sadly the dropping resistor ordered oem from nissan didnt start my car i guess im back to square one.
anybody hve any ideas,suggestions, advice? any help is great. thankyou!

you can email me at

[email protected]

thanks in advance!

[dsilvia89]

bump

my car started with the part after i grounded it out lol(drop resistor) but oil came out of my turbo, i dont know why. i need help!

[float_6969]

Where did the oil come out of the turbo?

[dsilvia89]

well i havent taken the turbo off bc hopefully i wont have to yet, anyay it came out of the "inside on the left of the exhasut housing. it feels like a bolt should be there. today i had a brain fart and thought maybe the line that goes near it is loose? is that an oil line?im not sure...its the one that goes in the middle and drops straight down....could it just be loose and sprayed oil ???

[float_6969]

Yup, that's the oil drain line. It's not really under pressure, although if it's missing a bolt and leaking, it could just be that it seems like the oil is coming from the exhaust housing, but it's actually coming from the flange of the drain pipe and running down the exhaust housing.

[gwar10]

ok so my question is this,if i dont have this plugged in would it cause the motor not to start/turn over??

[dsilvia89]

yep. need it to initiate the injectors basically. it will try to start but will fail everytime! get one, and almost sure shot this will be your problem. worked for me, also upgrade your spark plugs, makes a hell of a difference!