PLEASE HELP

[PSAT16]

i'm in the process of building my loom for my Peugeot, according to the E48 wire diagram there are only 2 pins (21+22) for the injectors. To me it seems that 2 pins are missing?? also pin 21 shares injectors and idle valve. am i missing something or should there be 4 dedicated pins for the injectors?

[stevieturbo]

The wiring diagram is very clear.

All 4 injectors will be trigger off a single ecu pin. You can share the load over the other pin too, but then you would lose the ability to run an idle control valve.

It's a basic ecu, no there is not 4 injector outputs.

[katana]

Think of the paired injector drives like wasted spark ignition - 2 cylinders fueled as other pair are sparking - this is called batch fire. 4 All together is group fire. Only real disadvantage is idle / low rpm fueling and emissions - over 2,500 - 3,000rpm you'd be hard pressed to tell the difference!

[stevieturbo]

Think of the paired injector drives like wasted spark ignition - 2 cylinders fueled as other pair are sparking - this is called batch fire. 4 All together is group fire. Only real disadvantage is idle / low rpm fueling and emissions - over 2,500 - 3,000rpm you'd be hard pressed to tell the difference!

They just fire them all the time, in no real sequence on either output, so doesnt matter.

For most engines, not a big deal. Ive ran mine in batch fire since day 1...will go sequential eventually, when I can be bothered to sort a cam trigger.

Only issues at low rpm might be with very large injectors, or very big camshafts. For 90% of cars, it really doesnt matter

[PSAT16]

ok thanks chaps that clears that up, i just couldn't get my head round why you would want to pulse an injector on an exhaust stroke etc but it all makes sense now

Next question is which idle valve/solenoid do i need to work with this ecu? i have the bosch solenoid type off my old Mi16 same as what older BMW's, Vauxhall's and others have fitted

[stevieturbo]

Most simple 2 wire solenoid types should be fine.

[Rob Stevens]

I'd suggest not using an idle valve until you have a good hot idle, one less thing to worry about to start with.