TBI GM MS3 PRO

Nosman · Post by **Nosman** » Mon Nov 02, 2015 4:40 pm

I'm in the process of building a turbo'd 4.3 Chev V6 with as MS3Pro, but in the meantime I'd like to get familiar with the setup etc so I've installed a TBI 4.3 complete with stock injectors etc. The injectors are 1.4 ohm, and I see in the manual it says the Pro won't directly support the use of low impedance injectors. Is there a quick and easy way to run these injectors for now until I get the other multiport setup built?

billr · Post by **billr** » Mon Nov 02, 2015 6:35 pm

Yes, search in the manual for info on "injector dropping resistors". It may not be the optimal solution, but the engine should run OK to play with and the MS3Pro drivers will be sure to be protected (probably already are, internally).

Nosman · Post by **Nosman** » Mon Nov 02, 2015 7:41 pm

I just did a search on those terms and didn't find anything relevant. Would there be a drawback to using 2 of the 3 extra 5A outputs with resistors?

billr · Post by **billr** » Mon Nov 02, 2015 10:10 pm

I'm not familiar with the Pro, so don't know what other drivers you are referring to. I'm sure Matt from DIY will join in here early tomorrow. In the meanwhile, start reading towards the bottom of this page to learn about use of resistors:

http://www.msextra.com/doc/pdf/html/MS3 ... e-1.4.html

Edit: Darn, that takes you to the beginning of the manual. You want this chapter: 4.10.2.4 Batch-fire - low impedance injectors - Injector Resistors

DaveEFI · Post by **DaveEFI** » Tue Nov 03, 2015 2:55 am

Nosman wrote:I'm in the process of building a turbo'd 4.3 Chev V6 with as MS3Pro, but in the meantime I'd like to get familiar with the setup etc so I've installed a TBI 4.3 complete with stock injectors etc. The injectors are 1.4 ohm, and I see in the manual it says the Pro won't directly support the use of low impedance injectors. Is there a quick and easy way to run these injectors for now until I get the other multiport setup built?

Don't know your original setup, but in general it's done one of two ways.

1)Resistors inside the ECU.

2)An external resistor pack.

But you could use individual resistors. Normal way is to fit them in the +12v supply to each injector.

Matt Cramer · Post by **Matt Cramer** » Tue Nov 03, 2015 6:34 am

I would use one 5 ohm, 25 to 50 watt resistor per injector. Like these:

http://www.digikey.com/product-detail/e ... ND/1646198

Or you could use an Acceleronics Versafueler or other peak and hold device - but that may be overkill for a quick test of the system.

Nosman · Post by **Nosman** » Tue Nov 03, 2015 4:23 pm

Thank you for the suggestions, I'll grab a couple of resistors tomorrow and have at it.

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