All this complicated stuff about at the moment about DIY FCDs. Well, I though nice idea, but not with my electronics skills...

So, having ploughed through lots of circuit diagrams & Japanese manuals, I have not got very far

Anyone fitted one of these things?
What part of the ECU does it actually want to talk to (or rather ignore)?
There are settings on the thing that are described in, suprise suprise, Japanese - having floundered around on the web I have found out about the voltage "editing" the thing does, but not the actual numbers so can forsee a great deal of trial & error (as in banging my head on the window from as little as 10psi I imagine ) looking for the right setting.
Any help would be good - Ta!

 

Have you tried http://www.racecarnewmedia.com/hks/ - HKS UK site they have some installation instructions there for their products - more specifically for the FCD http://www.racecarnewmedia.com/hks/fcd-manual.htm

Regards

Johny.

 

I think someone might want to have a word to their web guys to explain to them how to get their names onto search engines...

Thanks for the link - clears up quite a few of the 'little problems!'

Anyone know what a 'pressure sensor' or 'air flow signal wire' is? I'm guessing that the air flow signal wire is the MAF... I would also guess that the connection is whatever the DIY FCD "geniuses" are using. But what's that
Waiting for those 'answers on a postcard' with baited breath...

----
Just read stuff again - looks like I'm after the MAP sensor output. What that is I have no idea, but it looks like everyone has one . What does MAP stand for then? And even better, where would I find one...
I'm feeling a bit of a thicky at the moment if that makes anyone feel better about this constant drivel of questions I'm coming out with at the moment

[Edited by nom - 2/27/2002 3:22:59 PM]

 

Manifold absolute pressure. You are reducing or clamping the voltage to avoid fuel cut. The HKS FCD is not very precise if you see some results posted on the DIY FCD threads. It alters the voltage by too much for my liking below fuel cut, but so does MY01 PPP (10 PSI to ECU when it is really running about 18 according to one source).

We are working on a fuel cut lifter that does not change the signal at all until it needs to defend, and then it gives a new fuel cut. As far as I can see there is nothing on the market that does this. Whether the change in voltage below fuel cut is significant who knows, but at 2.29V you want it to be right as this is atmospheric and on the old shape the ECU reads atmospheric presumably as a trim for fuelling.

There is not commercial FCD I would trust on my car, although the HKS is nearest as you do still actually have a fuel cut - otherwise is unsafe in my opinion.

Raising fuel cuts is not for the faint of heart - you need to know that your fuelling and timing are OK with some reserve for adverse conditions - temperature or fuel.

Not to be rude, but if you don't know your MAFs from your MAPs steer clear and get it done professionally IMHO. No offence intended, but you keep your engine that way

 

The MAFs & the MAPs are OK & make perfect sense - I am in the unfortunate position of knowing (to a point ) how an engine works, but not the terms used by the individual companies for their engines. Oh the joy of moving a bit of kit from one car manufacturer to another... No offense taken, by the way It has been a day of confusion for me & Mr Brain has not been doing what Mr Brain is employed to do. I gave him a couple of beers & now he's happier
The MAF thing made no sense to me, but it seemed to be what the instructions were pointing at. I can also see (having looked at the graphs) that the HKS FCD appears to effectively work as if it were a simple variable resistor - by dialing a number in, the resistance is reduced by a percentage across the whole range - not the best option. What is preferable - and looks like you are working on - is for there to be no change in the ECU supplied voltage (via the FCD) until the normal fuel-cut bypass is reached, at which point the return to the ECU is constant until a defined (higher) input is reached (the new fuel-cut setting) when the return to the ECU increases to beyond fuel cut, therefore cutting the fuel at a safe but user defined level (presuming they are the same thing...). Your graphs seem to show that you're heading in that direction, but with a few bits of excitement on the way One of those things that I'd like to be able to help on, but can't remember half of what went on at uni anymore - big suprise And I never had too much luck with power supplies either

[Edited by nom - 2/27/2002 8:31:08 PM]

 

and just to make it more interesting you may also be able to use it on vehicles such as Evos which use a MAF mediated fuel cut, but with more potential to lean out the mixture.