[DeTomaso] EFI

[Kirby Schrader]

Good suggestions. Sometimes there are really strange things. I am trying to
tune my Pantera and was having difficulties. Turns out my 13 year old MAP
sensor is reading 45kpa when it should be saying 101. And it seems to be
intermittent at that. Makes for difficult tuning.

As a comment though... most systems I know about and have read about are
only closed loop during cruise.
I could be wrong, but they all switch off closed loop during full throttle
and fall back to a map.

These so called 'self learning' systems are all BS as far as I'm concerned.
You have to get close manually before you can go closed loop. There's no way
the system will compensate for something that's completely out in left
field. No way. I don't care what you read in the marketing blah blah blah.

This is the same as a carburetor. You have to pick the right type of carb,
CFM and jetting to get close and then you start tuning for YOUR engine. I
bought a carburetor once that was supposed to work as is. My car would
hardly run.

And remember... when a new EFI system is put on a production car, the car
companies literally have a full team of engineers and technicians who run
the engine on a dyno and then take the cars out to all parts of the country
and run them through tests in all conditions. Altitude, cold, hot, humid,
etc..
Why? To set up the maps and feedback loops so the system works as you would
expect it to when you buy it off the showroom floor.

Ever seen the documentary on the development of the Ford GT? They couldn't
even get the engine to START the first time around!
The 'EFI expert' of Ford ended up using what I think I remember hearing as a
program from a Crown Vic! Just to get it running! Then they started tuning.

So even the experts have to work hard to get a EFI system set up the first
time around.

And we're talking about each an every one of us having a completely
different engine. Different heads, cams, compression, bore, stroke, blah,
blah, blah.... so each and every map and setup will be different.

OK, I'm off my soapbox now... I like my EFI setups and will continue to use
them.

FWIW,
Kirby



On Wed, Oct 5, 2011 at 09:06, Mikael <mikael_hass at mail.tele.dk> wrote:

> Suggestions: I was sitting here thinking, can I suggest some remedy for the
> lean and severe bogging. Justin, I'm sure you've done all the sensible
> things, so I'll give you a few totally weird suggestions, forgive me.
> -Some EFI systems work strange if they don't get enough juice
> (electricity).
> Is your alternator fine? Grounding? Are there grounding wires from engine
> and gearbox to chassis?
> -I once had a car that did the same, but with a carb. It turned out to be a
> wire that was neither isolated nor fastened properly, so the g-force made
> it
> short against the engine
> I know, weird suggestions.
>
> Some comments, from many angles, from a carb fan:
> -Not many people can feel the difference between a properly tuned EFI and a
> properly tuned carb
> -On non-fuel-economy cars, I'd never do EFI. Why add complexity? Why spend
> money?
> -All carbs I've had have on an O2 meter shown a little lean when
> accelerating, and still have excellent throttle response
> -Buying things partly because the company claims to have experts sitting
> waiting to take your call is very optimistic. These are slightly trained
> call center employees, with targets on number of calls per day. My
> experience is that you quite soon know more about their product than they
> do
>
> Question: Are any of those EFIs closed loop? That's how OEM works, and if
> it
> is, then tuning should be unnecessary
>
> Mikael
>
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