now I know these have differnt resistance, but I am going to install these very soon, just wanna know if someone could give me the part # for a resistor, for the injectors, also where would I install the resistors, is there any things I should replace or watch out for when removing the UIM, I'm going to get all the required gaskets and such and put on my J-spec vaccum trap I got any help appreciated....

 

have fun! watch out for the coolant line under the UIM. it's a SOB to get disconected. just remeber where all the vac. lines and elecrical conectors go and it's fairly easy. also you might want to replace all the vac. lines while you got it all apart anyway. they are ALOT easier to get to with the UIM off.

 

Okay just talked to my mechanic he says I don't need to remove the UIM.....anyone care to elaborate.....how and where do I put the resistors

 

i don't know about the resistors, but you WILL have to take off the UIM to get to the injectors.

 

so I need to go ahead and get some gaskets then too, man why do these fools try and take advantage of me?

 

because that's how they make thier money. yeah, you'll probably need new gaskets. i know the first time i took off my UIM all my gaskets were worn out and cracked when i tried to take them off.

 

hey if you have a s4 you wont need resistor's cause they are low imp. and your old ones are low imp.

you have to take off your upper intake manifold

 

are you sure? I though the 720cc where high imp.....

 

if you have an 88, then most likely they are high impedence. I have an 87 and mine are too, cuz they changed from low to high like half way through the model year. You will need resistors though, because the 720's are usually low impedence, unless you get some custom made ones like mine...hehe.

 

Grab a resisitor pack off an early FC, take it apart, and use two of those.

I didn't have much luck with Radio Shack resistors.

 

you'll need different clips for the injectors also

atleast on mine I need 4 new ones square vs the round connectors on my harness.

 

well **** this seems like a damn big job, what year Rx7 can I get a resistor pack off of? So my injectors are high or low imp? man this stuff is to confusing for me this late

 

aight sorry found the info for myself, but still alittle confused the www.fc3s-pro.com site is the best, anyway here are some questions and quotes....

"Zenki FC3S after this build date and after this VIN split used high-impedence, red-top fuel injectors; these high-impedence fuel injectors turn pink with heat and age. The Zenki FC3S used rectangle plugs that were not compatible with the Kouki FC3S engine harness. "Low-impedence" fuel injectors typically measure about 2-ohms. "High-impedence" fuel injectors typically measure about 14-ohms. "


I have these ones in my car now, and I just read the lettering on the 720s and they say Denso? are these the greddy ones?

"There are also 720cc/min fuel injectors that are sold by GReddy for $130 each. These are also low-impedence fuel injectors. All the above mentioned fuel injectors are drop-in replacements. You can run other types of fuel injectors, but they will need some modification to fit properly."

"You can use low-impedence fuel injectors in a car originally designed to use high-impedence fuel injectors by running some 20-watt, 10-ohm resistors. You can use high-impedence fuel injectors in a car originally designed to use low-impedence fuel injectors by jumping the fuel injectors resistor block located at the front, passenger side of the engine bay. "

So how do I figure out if these 720s are high or low imp?

 

They are low impedance because the plug doesn't fit.

 

thank you

 

okay so if the plug won't fit then how do I make it fit? and how exacly do I jumper the fuel injectors resistor block?

 

Your car doesn't HAVE a resistor pack. You have to add resistors to your high impedance car to use the low impedance injectors.

Go to the auto parts store and get the plug. I think its a Bosch plug that fits those...

 

sorry the dark pink looked red, they do have the square injectors...

 

Ok half way through 87 the injectors changed from low impedence to high, so you have high for sure. You need to take off the UIM so order the gasket from www.mazdatrix.com. Its like $3. Also order all new grommets and o-rings for your injectors, so just call them up and tell them what you are doing and they will hook you up. I'd get some fuel hose and vac. hose and replace everything you can while you have it all apart. I replaced my PD while mine was apart.