How do AICs work?

[Daniel Houlton]

Bruce Plecan wrote:
> 
> 
> -----Original Message-----
> From: Daniel Houlton <houlster at user2.inficad.com>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Friday, March 05, 1999 10:04 AM
> Subject: Re: How do AICs work?
> 
> While it's common practice not to exceed 85%, if your oem calibration does,
> what makes you believe that for that application 100% is wrong?.

Because of everything I've read on fuel injecton and injectors say that a 
duty cycle that high will damage the injectors in short order.  Some say 80%
is the limit.  Some say 90%.  But they all agree that 100% is bad.

Also, I doubt my OEM calibration does exceed 80 or 85%.  The engine never
made enought hp stock to need it.  It's only hitting 100% I'm sure because 
of the extra hp the turbo is making.


>   You mention smog police, and steathy, ya really think they'll miss the
> turbo?.

Not sure.  I'm in AZ and I've found them to be somewhat liberal in what they'll
let pass as long as it looks safe and passes the sniffer.  I had an un-
certified header last time I went in, but it retained the EGR and O2 sensor
and passed the sniffer no problem so they didn't say a word.  I also called 
before putting the header on and spoke to one of the techs that do the tests.
He said as long as no smog equipment is removed and it passes the sniffer they
don't much care if the actual parts have an smog number on them or not.

My turbo actually looks very factory installed other than the induction hoses
which I plan to re-do by then to make it look cleaner and neater.  I do 
believe that unless I get one that know Amigos, they won't know it didn't 
come from the factory.  And even if they do, I doubt they'll flunk it unless
I mess with the smog equipment or it fails the sniffer.  The extra injectors
and lines just make it look less factory.

> Did you ever figure out for sure if the MAF is voltage or freq?.

It's definitely voltage.  Previously I had it only up to about 4.3 V, but I
hooked the meter back up to it last night and took it out on the freeway and
at high loads and boost, it got 5.7V out of it.  This was around 4500 rpm or 
so and about 8 psi of boost which isn't quite where the injectors maxed out 
yet.  The MAF has 3 wires: 12V power (regulated 12V I think, not battery 
voltage.), ground and the signal wire.  I really would like to get it flow
tested to plot the V out against the cfm it flows.  Can't find a place that 
can do it though.

I did check the manual for my automotive multimeter and it turns out it can
measure frequency from MAFs (RTFM right?) using one of the modes intended 
for measuring rpm.  Havent tried it yet though to see.


thanks
--Dan