ST185 Fuel Injector Resistor Pack Location and Wiring

Lucid

New member
Hi there guys, this is my first technical post here, so sorry if I get anything wrong. I tried to do as much reading as I could to avoid redundant posting.

After an unfortunate blunder while changing out the fuel pressure regulator on my GT-Four, I ended up damaging 2 of my fuel injectors (still kicking myself over this...) and have a brand new set of 4 on order, should be here tomorrow. One possible problem is: they are high impedance injectors, and from all the research I've done, the EFI system on the ST185 runs with low impedance injectors from the factory. I've done a bit of reading on this forum and I learned that using high impedance injectors is possible (and some people actually recommended it), however, from what I understand, I would have to do some wiring to bypass the factory resistor pack for the fuel injectors. I believe it is either located under the battery or near the strut tower, so I will try and locate it myself. Does anyone know what piece I should be looking for exactly? Something with a heatsink and electrical connectors, I assume? Also, if necessary, what is a good way of bypassing these resistors for the fuel injectors?

Thanks guys.
 

grip-addict

Active member
Have a look at this, it's an MR2 but the plugs are the same.

On our car, it's under the battery tray. You'll see 2 little gray boxes that look like they are heat sinks. One's for the fuel pump, the other for the injectors.

What injectors did you buy to replace your factory ones? It could be a more-involved job, depending on what you are planning on using.
 

Lucid

New member
Have a look at this, it's an MR2 but the plugs are the same.

On our car, it's under the battery tray. You'll see 2 little gray boxes that look like they are heat sinks. One's for the fuel pump, the other for the injectors.

What injectors did you buy to replace your factory ones? It could be a more-involved job, depending on what you are planning on using.
I love Mighty Car Mods haha. This seems like a good way to go about it, will try it out when I get everything put back together.

I know that putting in bigger injectors means tuning the ECU for them and, as I can't afford an aftermarket ECU at the moment and just want to get the car back on the road (it's been sitting since September of last year), I just went for rebuilt OEM 440cc high flow injectors from KSM Motorsports. However, after reading what some people are saying online, I don't think I want to risk putting them into my car, might just return them and try and find another actual Denso injector. Finding real OEM injectors with the same part number for the ST185 has been a massive pain though...
 

Lucid

New member
Small update from last week. I just decided to replace the filters I broke on the old stock injectors with the injector filter and seal kit from Prime MR2: https://primemr2.com/collections/gen2-3sgte-parts/products/fuel-injector-o-rings-gen2-gen3-3sgte. Finding stock Denso injectors is nearly impossible and when I did, they were either too expensive or the sellers never replied back to my emails/messages.

I also bought the TwosRUs manual boost controller from them as well to replace the shitty ebay one my 185's previous owner left on. I've heard many good things about them, so I'm looking forward to getting it on!

I am very glad I did not go with the KSM injectors that I got. Saw some guy on youtube almost hydrolocked the 2JZ in his Supra cause of them. I can't speak for the quality of the ones I got in specific, but I don't think I could recommend them based on just the little bit of research I did. Trying to send them back and get a refund, but the person running the company is taking forever to reply...
 

grip-addict

Active member
there you go, that's one way to go. If you send your injectors out to someone like witchhunter, i think they replace some of those seals for you too. Probably worth checking me on that just to make sure though, it's been quite a while.
hope you get up and running soon!
 
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