MSefi.com read only forum (Jan.15,2018)

Hi,

I just finished ordering parts to repair my flyback circuit from digikey and I want to avoid blowing it again, I am running a v2.2 megasquirt fuel only on a 1.8 4 cyl vw g60 engine t3 turbo, the car ran great until it was stored for a year and upon trying to start it, the flyback failed and flooded the cylinders with fuel, I checked and the U7 and it is cracked.

The injectors are high impedance 32lbs ford motorsports wired in parallel, I was thinking of wiring them up in 2 batches so that the resistance doesn't go down as much, my question is what is the best way to wire them up, as in 1-4, 2-3 together? Or 1-2,3-4? the original injection system had them all together to one plug firing at the same time, that was why I kept them that way originally.

I hope someone can help me.

Thanks

Don't wire them in series, you'll double the voltage of the flyback spike.

Matt Cramer wrote:Don't wire them in series, you'll double the voltage of the flyback spike.

Sorry, if I didn't make myself clear, I meant make 2 batches, each batch with 2 injectors in parallel, but I just wanted to know if there is a particular way I should make the batches, as in, cylinder 1 and 4 in parallel and 2 and 3 together, or 1 and 3 then 2 and 4, I only ask because if the car used to need all 4 at the same time to run, wouldn't running alternating on 2 batches make the car run lean?? Correct me if I'm wrong. Thanks

The ECU changes the pulse width to match how the injectors are staged, so there's no AFR difference between alternating and simultaneous. I've seen injectors paired every way imaginable and there isn't a huge difference, though supposedly pairing 1/4 and 2/3 is best. Supposedly. Several of our own project cars use 1/3 and 2/4 pairings and work fine.

so let's see if I understand this correctly, the ign firing order has no advantage on the staging for the injectors.

Slave2theBunny wrote:so let's see if I understand this correctly, the ign firing order has no advantage on the staging for the injectors.

It might be more accurate to say that there may be an advantage, but it's so small it is hard to tell for sure.

Slave2theBunny wrote:so let's see if I understand this correctly, the ign firing order has no advantage on the staging for the injectors.

My RV8 was originally fitted with Lucas Injection which does alternating batch. The injectors were grouped 1357 and 2468.
When I first fitted the MS I stuck with that - then when the loom needed modifying for EDIS, I changed to 1467 and 2358.

I think the idle and very low speed torque is better - but couldn't swear to it.