Injector resistence

[kapower06]

Nissan KA24E Top feed 260cc High S13Nissan CA18DET Top feed 370cc Low S13

Now that we know that ca's are low and ka-e's are high what, if anything, needs to be done to use the ca injectors with a ka-e...Orion said to use an injector resistor from a prelude? Someone on these forums has to have had a ka-e with ca 370's at one time or another. Thanks

[DRIFTEADOR]

the diagram is for honda wiring so the colors will be different, but you get the idea. the resistor box is intalled inline between the same color wire and ecu and the other goes straight to the ecu. the resistor box can be pulled from any 88-91 crx, there should mbe plenty of them in your local yunk yard or try ebay. its located by the firewall on the drivers side and looks like this:

[kapower06]

Would it just be possible to solder in some 10-11 ohm resistors "inline" with the injectors ? im about to just buy a 8:1 rrfpr, then save up for a SAFC or just go with DeviousKA's advice and modify my stock SOHC ecu and run Live Edit with a lap top. ughh so many options...lol... sorry for jacking the thread. thanks

[hannibal]

Thanks for the corrections Bri.

I posted my injector spread sheet and its now a sticky. In case anymore situations arrise like this one.

...Thats my spreadsheet. But thanks for posting it in a text format...The complete spreadsheet can be found at http://wes.spilky.com/injectors.xls. I do have some updates/corrections to make, but I'll be sure to let you know.

Thanks again to Wes and Jesda for hosting...

[onosqv]

Nissan KA24E Top feed 260cc High S13Nissan CA18DET Top feed 370cc Low S13

Now that we know that ca's are low and ka-e's are high what, if anything, needs to be done to use the ca injectors with a ka-e...Orion said to use an injector resistor from a prelude? Someone on these forums has to have had a ka-e with ca 370's at one time or another. Thanks

Well, I'd hate to bring in more confusion, but I dealt w/ this issue a few months ago too. This was discussed last year.

CA18DET are HIGH IMPEDANCE. They are listed as LOW because they are attached to a resistor - the injectors themselves should be high impedance. I think this is the source of the confusion.

So... IWannaS15, I hope you are able to accomodate for HIGH/LOW injectors in your chart w/ a list of which ones have resistors (that would probably be very hard, but may an *astericks or something).

So, if you have ca18det injectors, they should in fact be high impedance and will drop right in.

The CA18DE (non turbo), I believe may be low - not sure about that one.

Only reason I know this is because I have a set of ca18det's I bought and was scrounging for info back in October 2004.

Don't take it from me:[quote=""Toahk""]Ok just found out, stock ca18det injectors are 370cc low impedance, top feed. Stock Ka24E injectors are 270cc high impedance, top feed.

Edit, 370's are actually high impedance with a resistor to make them low impedance. Just remove the resistors and jumper the wire where it was. [/quote]Original Thread:zerothread?id=82238

Edit: So.... LemHead16, check to see if you are measuring your injector w/ the resistor wiring still intact.

another edit - to quote myself cuz I'm a ho:

I believe he is saying you only need resistors when you are trying to go to low impedance resistors.

The CA injectors are high impedance if you don't use the wire (which contains the resistor to make it low impedance).

So basically, I believe it is just plug and play.

KA24E - high impedanceCA18 - high impedance w/o the wiring

[hannibal]

You confused the hell outta me for a second, but that makes sense.If the injectors were in fact low impedence, you couldnt put a resistor box in front of them. Resistors can only increase impedence, implying you would only put a resistor box between high imp injectors and an ECU designed for low imp injectors.

But the resistor box is separate and I'm sure LEM checked them without the box attached. Now I'm confused again.

THese are the only possiblities of ECU/resistor box/injectors.

High - no box - HighLow - box - HighLow - no box - LowNote you cant drive low impedence injectors with a ECU designed for high imp.

Does this makes sense or am I a dumbass??
Modified by IWannaS15 at 6:38 PM 3/31/2005

[DRIFTEADOR]

wrong, resistors create a higher resistance/impedence (measured in ohms; the higher number the greater the resistance) against current. without resistance your ecu injector drivers would burn out from too much current.

[hannibal]

Umm, thats what I said. Resistors can only be used to raise the impedence (resistence) between the ECU and injectors. Thats why I think its only possible to use a resistor box between a LOW imp ECU and HIGH impedence injectors. If this box wasnt there, you would burn up the drivers from too much current as you said.

EDIT: I just read the link that Broke posted. Slipnfall mentioned that you can lower the resistance sent to the injectors by wiring resistors in parallel (instead of series).My circuitry skills are lacking. Can anyone say for sure if that Honda diagram has the box wired in parallel or series?

EDIT2:I'll shut up now cause I am in fact a dumbass. I'm totally confused...
Modified by IWannaS15 at 7:00 PM 3/31/2005

[DRIFTEADOR]

all injector drivers/ecus are the same. a car that uses a low impedence/peak-hold injector needs/has resistors.

slipnfall was wrong, you cant lower resistance, nor would you want to, by wiring resistors. that would do the exact opposite.

[LEMHEAD16]

Can we say Confusion.

I can tell you the facts about the injectors.

CA18DET = low impedence directly at the injector terminals, unless there is a resistor inside the injector but I think not

KA24E = high

So far I think the "honda box looks best" (shudders)

[turbo90]

If I remember physics 2 correctly, two resistors in series add i.e.: R = 12ohm (injector) + 2ohm (resistor) = 14 ohms. However, in parallel it's different 1/R= 1/12(injector) + 1/2(resistor) = 1/0.583 = 1.714 ohms, close to a low impedance injector. But make sure you have some stout resistors.

[hannibal]

I was confused by thinking that low impedence injectors want a low resistence current. But actually they create a low resistence circuit because theyre internal circuitry has low imp.

If your ECU expects high impendence injectors (and you want to use low imp injectors), you would need to add resistors to increase impedence of the circuit and keep the ECU happy. If they injectors are high imp, they already have enough resistence to keep the ECU/drivers from flowing too much current.

So if the CA ECU is high (I think most are, and Driftador agreed), then the injectors themselves must be low if it uses a resistor box. Lem's test supports this.

YOu can lower the resistence of a current by wiring injectors in parallel as slipnfall said and turbo90 calculated.

[kapower06]

I currently have a set of ca 370's, so in order for me to run them on my KA-E I would need to add a resistor to each injector?if so could someone point me in the right direction as to where and what kind? thanks.

[LEMHEAD16]

any body have other Ideas

[DRIFTEADOR]

what else do you need to know?

[dsmdriftEG]

So plain and simply i couldn't use low impedance DSM 450's on my KA24De-turbo? unless i get a resistor to take the high impedance ecu and resist it to low impedance injector?

[:: orion ::]

^^^ Correct...the easiest solution is that Honda resistor box, posted above.

- Brian

[dsmdriftEG]

thanks orion that was the most confusin topic i have seen in a while, everything is cleared up now. Thanks again.Sean

[LEMHEAD16]

Okay I got the box now for a wiring question. It has four black wires and one red wire. How exactly does it wire into the injectors?

[:: orion ::]

Your injector shave a big wire and a small wire...I consider the small wire the "ground" (although there is no poarity).

According to the diagram above, you interrupt the ground, and wire all 4 to the red wire.

Then connect one black wire to each wire on the harness side of the injector wiring.

...at least that's my interpretation of that diagram.

- Brian

[LEMHEAD16]

That is what I was thinking brian but I wanted to check before cutting wires

[deezlins]

If you put resistors inline with peak and hold injectors when using a saturated ecu, wouldnt it prevent enough current from getting through the ecu to the injector.