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SJ G16A SPI Swap Questions/Considerations.

Posted: Tue Jun 16, 2015 1:23 pm
by Scratch
It's time to swap the tired G13 for a G16 and I'm going down the SPI route, got no worries with regards to making a new loom etc. as it wouldn't be the first EFI swap I've done, would be the first Suzuki EFI swap though so your collective knowledge will be much help. The lump and ECU etc. are from a 1996 Vit.

What fuel pump are people running for this job?

Anyone running without the EGR and Purge Canister, if so has the ECU spit its dummy out?

From what I can tell from the schematics the ECU sends the EGR VSV coil to earth and does the same for the Purge too, does the mapping adjust mixture to compensate?

Cheers.

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Tue Jun 16, 2015 9:05 pm
by twiss
To be honest I've not gone for EFI and am still on carb so can't be that helpful.
I do know a little bit about the fuel pump though.... it should kick out between 10-15psi

The original Suzuki pump was an in tank pump but I dont see why you can't run an external pump for it.
There are a few options on web sites like Demon Tweeks

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Wed Jun 17, 2015 7:49 am
by Scratch
Cheers Twiss, I have read somewhere in the depths of the internet that the pump should be somewhere between 34-38 psi? Though the first thing I noticed about the net and SPI info is that its here, there and everywhere, lol.

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Wed Jun 17, 2015 10:42 pm
by twiss
38 psi is heading towards the region of a multi point injection system and you need decent braided hoses

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Thu Jun 18, 2015 10:58 am
by Scratch
Had a study of the FSM and answered my own question :screwy: 34.1 - 39.8 psi. It seems that the SPI and MPI use the same in tank pump. Most MPI systems still only fire one injector at a time and many EFI system require a fair amount of pressure to keep the valve inside the injector closed.

Now... will the ECU allow me to delete the EGR, I hope so, never liked the idea of dirty gas being passed back through the clean side. Better pull my finger out and get this engine rebuilt so I can have a play.

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Sat Jun 20, 2015 5:55 pm
by Rhinoman
The pressure is controlled by the regulator, you need a pump that will give enough pressure at the maximum flow rate. Evap. canister can be removed but removing the EGR is likely to cause the ECU to revert to a fail-safe mode.

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Sun Jun 21, 2015 8:49 pm
by Scratch
Rhinoman wrote:Evap. canister can be removed but removing the EGR is likely to cause the ECU to revert to a fail-safe mode.
Is this because the ECU is expecting to see some resistance at that pin? If so would it be possible to replace the EGR with a resistor to emulate it?

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Mon Jun 22, 2015 9:47 pm
by Rhinoman
On later models it flicks the EGR open on the overrun and looks for a change in manifold depression.

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Tue Jun 23, 2015 12:56 pm
by Scratch
Thanks Rhinoman....

On how later models does the mapping do this? I have a 33920-71E70 N1 ECU, can it be remapped?

Re: SJ G16A SPI Swap Questions/Considerations.

Posted: Tue Jun 23, 2015 1:16 pm
by Rhinoman
I think its 94-on, maybe 96-on. The 71E70 is a 94-on, as stock it can't be remapped. I did make a prototype daughterboard for one a few years back which I use for bench testing but I haven't made a production version.

http://rhinopower.activeboard.com/t4317 ... itara-ecu/