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red '91 VR-4
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361 Posts
Discussion Starter · #1 · (Edited)
I've been running e85 on some DSM 450cc injectors for a while now and decided to upgrade to FIC 1800cc (probably overkill but wanted to be ready for turbo upgrade).

The AEM EMS S1 has no option for FIC 1800cc injectors for the battery offset table, so I chose the closest one (RC Engineering 1600cc - 3ohm).

I also scaled the fuel map and the crank injector time table.

Now she won't start and the spark plugs are bone dry. It looks like she's not getting any fuel whatsoever. I can confirm that I'm getting 45psi fuel pressure at the rail and spark from the plugs.

I also tried to manually input a whole bunch of battery offset values to no luck.

Anything I'm doing wrong? Was it wrong to assume that these injectors would be plug-n-play? Like a dumbass, I threw out the old 450cc injectors :(

I didn't adjust the microsec / bit value because I don't really know what it is. I just know that I want to adjust it to keep the raw fuel numbers reasonable.


EDIT - Fixed!
 

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One fix at a time
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8,172 Posts
I thought maybe it was a low-z/high-z injector change issue but it appears the 1800s are low-z injectors meaning you don't have to delete your injector resistor pack to run them(required for high-z injectors). I assume you need accurate battery offset values for the injectors even if you have to create your own custom table.

Are you sure your injectors are actually firing? You said plugs are bone dry. You can pick up an injector noid light to plug in and see if it lights up. That will show you if the injectors are getting signal and firing. I'm suspecting they may not be for some reason which could be crank sensor related, MFI, or ecu. Definitely check to make sure they're firing first. Depending on how far off the battery offset values are and the cranking time, you may not have anywhere near long enough opening ms time but I would first confirm if they are firing before you get too carried away.
 

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Premium Member
1994 3000GT VR4
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933 Posts
I worked with a v1 a long while back. Not sure about battery offset and how it applies to injectors. Have you tried starting over with the previous map and scaling just the fuel table for 25% of the fuel (-75%)? Or maybe try the previous crank injector time first to see if it even starts or injects. Curious how things will progress.
 

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SDSU Alumnus
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4,122 Posts
I hope that you saved an older version of your cal lol. Use injector flow/pressure wizard instead... afterward, enter battery offset from your included spec sheet and voila. Easy peasy.

Any other issues are coincidental or circumstantial from your installation.

-sent from my Galaxy Note 9
 
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red '91 VR-4
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361 Posts
Discussion Starter · #5 · (Edited)
Are you sure your injectors are actually firing?
I was so focused on the AEM that I didn't even check the basics :)

Thanks for the suggestion. I don't have a noid light but just used a standard voltmeter and found that I'm not getting +5v to the harness (checked against battery ground as I understand the harness ground is controlled by the aem). It's possible I didn't seat some connector snugly when putting the car back together. Oh well, at least I have a diagnosis path now. Thanks!
 

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red '91 VR-4
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361 Posts
Discussion Starter · #6 ·
Yup, sure enough, I didn't seat the connector into the external resistor pack on the firewall tightly enough.

After that, I input the battery offset data from the data sheet, fiddled with the crank injector time table and the fuel map (the wizard got me close but wouldn't start without some minor adjustments). Now she starts right up and idles beautifully! I'm actually really surprised how smooth of an idle she has!

Thanks everyone!
 
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