Having trouble getting my new rebuild to start. I am using low imp 550cc injectors on a high imp harness. Ive soldered in resistors just behind the injector clips.. is this the correct area to wire in the resistors? Ive got spark, but since its a rebuild with used housings it is probably low compression. Ive already tried pop starting the car which will do nothing. The fuel pump is working and ive got fuel in the lines but I dont know if the injectors are working or not. Now if I were to take out the cas, put the key to run, and spin the CAS gear, would I be able to hear the injectors working?

 

To avoid mistakes, we recommend people install the resistors at the ECU. You have to make sure they are not installed in the power wires, only in the ecu driver wires. They go in the light green wires. Also make sure that you use heavy duty resistors (10 watt)

 

Could someone post pics of your resistors soldered in at the ecu, or post a really good explanation of exactly how to do it?

Sorry if im jacking your thread, but maybe this could help both of us.

 

I think I have an idea what he is saying. So I would wire the resistors on wires next to the ECU plug. If I were to wire it up, how would I test it to be sure that injectors are working before I put the intake back on? As in what kind of voltage, resistance, etc should I see at the injector clip?

Check attachment for where to wire the resistors..

edit: by the way the injectors were cleaned, tested, and flowmatched by witchhunter

 

I found that in the FSM but i have no idea what im looking at.

 

you need to study them than and get more familiar with wiring diagrams before you chop into the car.

 

These wires are Light Green/Red, Light Green/Black, Light Green/White, and Light Green. They come out of one of the plugs on the ECU, the plug is called EM-03. Thats basically what that part of the diagram says. You would cut those wires and wire resistors in there if you are running low imp injectors on a high imp harness. Thats the best way I can explain it.

 

^Thats what i was looking for. Thank you.

 

Don't 99% of the OEMs put the resistors on the power wire since they use a "bus-bar" resistor arrangement,including the S4's that were OEM with low-Z injectors?What's your reasoning, I was under the impression it didn't matter if it was on the 12volt line or the ground line(ecu driver line as you call it).

 

The ECU fires the injectors by grounding them. This opens the coil in the injector, causing fuel to spray. The resistors are to protect the ECU, by installing them in the power wire, you have not accomplished the job of changing the injector resistance. This in turn fries the injector driver in the ECU. It can also cause the injectors to stick open.

Soldering the resitors at the ECU also protects them from the Heat of the engine. The flame resistant resistors are only ceramic which means that they do not like to be bounced around. The 12v power wire does not go to the ECU.

However you can put them where ever you like, I am just telling you how we do it.

Here is a pic of them soldered in line on our project vert with 1680 secondaries.
http://www.banzai-racing.com/how_to/..._installed.jpg

 

With low imp. injectors,aka "peak-hold" you need to limit the current the ecu sees so you don't fry the injector driver circuit.It doesn't matter if it's on the supply or the ground line of the injector.

I agree if you are using individual resistors, then it's a better and easier idea to put them near the ecu instead of just before the injectors for the reasons you mentioned.

Nice work, by the way on getting the FD power FC to work on the FC3S and thanks for sharing the how-to.Have to give that a double thumbs up..cheers