rev counter? Idle Air Controller (IAC)?

[damo_S13]

will as im getting closer to having then engine in. i got a cupple of problems/ questions

1. how do i get my rev counter working? 

2. do i really need a Idle Air Controller (IAC)? can i run with out one ok? i have no were to fit one at min due to using a custom inlet manifold

thanks
damo

[cliffb75]

If you're not to worried about idle quality then you don't need an idle air bypass valve. Just set up the ignition map at around 10BTDC at your chosen idle speed and then kick it up below that to help avoid stalling. Not great but a certain UK car maker had their cars setup like this for years...

[damo_S13]

cool that will do me

thanks
damo

[rob@vems.co.uk]

Thanks for that Cliff, its a handy idea that will overcome the stumble that some get when we use the spark retard/cut features for idle control.

Onto RPM... Its a case of finding out what the stock Nissan ECU uses, with most of the cars I've done we've been able to use a feed through a small diode network to give the tacho the trigger it wants.  I see that the Nissan RPM count comes from the ECU so I'm thinking that we're probably going to only want to give the gauge +5v pulses.  I've put it on my to-do list and I'll get looking later today.

[dnb]

I've been using the "valley" method of setting idle ignition advance for the past year.  It works very well when combined with the advance trimming method of idle control.  I can turn off the stepper air valve and not lose much idle quality at all.

I expect the rev counter just needs a pullup resistor to +12v or +5v since it was ECU controlled anyway.   Some kind of protection diodes would probably be a good idea, although I don't think a rev counter can kick much...

[damo_S13]

ok cool thanks bud

i really need to be spoon fed a little with this info tho 

anyone got a good i idea on what i need to do for the tacho or a little wiring diagram would be great lol

i know which wire goes to the tacho now i just need to know where to wire it to with what elss in between

thanks for all the help

damo