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High or Low Imp Injectors with resistors??

Posted: Mon Sep 03, 2007 3:18 am
by slabbielad
Right then,

I'm sure this topic has been done to death by many people.....but here we go!

I'm going to be running Microsquirt on a bike. I needed injectors with the barbed type of fuel pipe connection. This limits me to older Japanese style injectors which are all low imp. I ran low imp on my car with resistors which worked fine. Microsquirt can do the peak & hold so I can either go for peak & hold or resistors & treat them as high imp.

The real question is am I better using peak & hold (no resistors to package, go wrong, less connectors etc) or resistors (I have experience with & less setup variables).

I know some OEMs use (or did use) low imp injectors with resistors (Nissan & Toyota certainly did). Was that just to make use of existing hardware?


Already have the resistors & made a heatsink, just wondering is necessary!

Any thoughts?


Stew

Posted: Mon Sep 03, 2007 5:47 pm
by car46999
When you say barbed, you are referring to the fuel connection I assume? I have seen injectors with barbed inlet/outlet to run a series of injectors from one supply. These were on Italian bikes (ducati's guzzi's). Also I know the ducati injectors off a monster (yr 2000 and up) are high imp (15ohm) and barbed. I probably have a picture if you needed one.

Hope this might help

Posted: Wed Sep 05, 2007 7:53 am
by Matt Cramer
The typical '80s and earlier low impedance injectors ought to work fine if driven through a resistor pack. They're pretty easy to find on MR2s and the like. It's newer, super high flow low impedance injectors you have to watch out for. On some of these, they need a lot of current to pop open.

Posted: Sat Sep 08, 2007 6:36 am
by slabbielad
Thanks for the responses.

When I said barbed I did mean the fuel inlet unions. I have a tubular fuel rail which has stubs to take the short flexi tubes. It's easier to stich with the hardware I already have rather than spend time rengineering (me being lazy!)

The injectors I am using are Nissan Ca18ET items which are 270cc/min with 3ohm coil resistance (I already had a good set to hand!)

Sounds like resistors are the way to go (already have the cleaned low imp injectors installed!).

Thanks,

Stewart.

Posted: Tue Sep 11, 2007 6:20 pm
by larryc