Board logo

Running injectors in the wrong sequence
Furyous - 13/11/16 at 09:59 PM

I'm in the middle of rewiring my duratec Fury. The engine has only been run for short periods while the car has been off the road for the last few years. Each time it's run it's had a lot of black smoke from the exhaust. Ive tried all sorts to fix it but while rewiring I realised I've had my injectors paired up as 1+2 and 3+4 all this time. I always thought I had them correctly paired as 1+3 and 2+4. What effect would running them in the wrong sequence have? I'm not close to having the wiring running yet so I can't just swap the injector plugs around to check.

I'm using Microsquirt v3 with EDIS wasted spark.

Slimy38 - 13/11/16 at 10:47 PM

I might be wrong, but it doesn't make that much difference, maybe a few bhp or a bit of fuel economy? It shouldn't be the cause of black smoke.

Happy for someone to say I'm wrong though.

adithorp - 13/11/16 at 10:56 PM

Shouldn't they be 1+4, 2+3?

luke2152 - 13/11/16 at 11:05 PM

I'm sure off idle it makes no difference at all. Might make a small difference to idle smoothness and emmisions when the engine is running slow enough for the injector to inject at the precise moment it wants to but at medium/high speed it is just pulsing away constantly. Think of a carb - it has no timing control at all over the fueling and still runs relatively well

britishtrident - 13/11/16 at 11:09 PM

Yup. 1 & 4. 2 & 3 are companion cylinders for both fuel and ignition

adithorp - 13/11/16 at 11:51 PM

quote:
Originally posted by britishtrident
Yup. 1 & 4. 2 & 3 are companion cylinders for both fuel and ignition


Thanks for that... I thought I was having a "grey moment" as nobody else had said it

Furyous - 14/11/16 at 01:13 AM

I'm confused now! The old MS diagram I was using shows 1+3 and 2+4 paired but all I can find online now shows 1+2 and 3+4. Sounds like it doesn't really matter, though. I do have the spark plugs paired as 1+4 and 2+3.

It's been so long since I last ran the engine that I can't remember if I sorted the smoke. It just crossed my mind when I saw how the injectors were wired.

Edit: Here's the diagram I was looking at showing 1+3 and 2+4.



[Edited on 14/11/16 by Furyous]

coyoteboy - 14/11/16 at 01:59 AM

It really won't matter to the engine off idle, as mentioned. You could fire all at once or one at a time off time and it would still run, you'd just find the idle a bit harder to tune.