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bosch pwm


Grant.
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hi all!! I am using a bosch pwm valve (bosch 0280140516) for my megasquirt set up.

In my wiring diagram i have 4 wires (red&green, green&white, blue&white, orange) however only 2 wires on the replacement stepper motor/ air solenoid.

post-10226-076684600 1286227233_thumb.jpg

Anyone able to help me out? which wires do i need??

Thanks in advance!!! :D

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I thought bank fire was pretty rubbish when I looked it up too. The injectors just atomise fuel near the intake valve and it sucks it in. You can get sequential fire but I think the timing is tricky to get exactly right and can do more harm than good. I think the idea is the air near the valve is fuel / air and the valve just sucks it in when it is ready.

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First off, that diagram is for a stepper motor idle valve (4 wires, needs MS-2 to control it) so ignore that part. There is info on wiring Bosch PWM valves either in Nige's thread (I'm guessing, be surprised if there isn't) and on the MegaSquirt forums.

This is the diagram you need, note it says "Fast idle, not used on RV8" this was for the old on/off idle valves but PWM idle uses the same pin.

DB37_V3_EDIS.jpg

Bank fire is fine, sequential intuitively seems like it should be better but it only gains a little at low RPM & idle. Most sequential systems "fall back" to bank fire as the RPM and load increase simply because there's no point doing otherwise. Most of the time, injectors are firing at a closed valve anyway (think valve opening duration Vs injector open-time per cycle). There's loads more on this on the Megasquirt forums & megamanual as almost everyone asks the question first time out - I did ;)

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Bank fire is fine, sequential intuitively seems like it should be better but it only gains a little at low RPM & idle. Most sequential systems "fall back" to bank fire as the RPM and load increase simply because there's no point doing otherwise. Most of the time, injectors are firing at a closed valve anyway (think valve opening duration Vs injector open-time per cycle). There's loads more on this on the Megasquirt forums & megamanual as almost everyone asks the question first time out - I did ;)

So did I. I think it was the mighty Bruce Bowling himself that tested it vs sequential injection. His conclusion: f all difference!

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Thanks guys for the input! Really appreciate it, just trying to understand EVERYTHING! ( or near as damn it! :lol: ) before my friend and I let loose with fitting the new engine and megasquirt set up. I realised about the injector wiring though after i found an old 1990 range rover efi wiring diagram, which only had 3 different wires doing all the injectors aswell, so after that I assumed it was the way!

Cheers again guys for the help though. Really appreciate it!

Will get on with getting it all in and running now! :)

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