Small TBI question (of my own)

[George Bearden]

I have a Suzuki Samurai and it is my daily driver, though increasingly I
have tilted the 'compromises' towards the off-road driving I do.  I have
done a lot of mods for off-roading, and a buncha engine mods but I still
have the stock electronic carb.  

I am interested in a fairly cheap & available EFI.  Suzuki uses a TBI
starting in the early 90's but some report that it is fragile and eats
ECM's off-roading, and they are *expensive*.

I have been considering a small GM TBI unit and have been reading all I can
find on the topic.  I'd appreciate any suggestions for books that offer
good info on these TBI units.

There is one fella I heard about who used one off of a 2.5L Sunbird
successfully (the Suzuki is 1.3L).  Which leads me to a couple of questions
I have been playing with.  If the TBI's tables are appropriate for a 2.5L
engine, how well will it run in open-loop and WOT?  The fella who did the
swap reportedly has his running well.  He has lowered his fuel pressure and
I am guessing this is to bring the amount of fuel delivered closer to
stoich.  But with stock fuel pressure will it 'learn' to deliver the
(approximately) correct mixture in open-loop?  I don't know which year
model or ECM he used, but I guess I don't really care as I am attempting to
determine for myself which would be a good candidate.  I don't know much
about these.. I am wondering if the smaller single-throat TBI's used BLMs,
and if so, will they have this effect?  Is it desirable in light of my
application to attempt to find an ECM that uses BLMs?

My goal is to have more power, better driveability, better running at
severe camber angles, and an attractive replacement for the tempermental
stock carb and fragile stock TBI.

Regarding Ron Schroeder's previous question:
> Why is WOT open loop?  Wouldn't it be better to be 
> closed loop or is feedback response an issue?

I understood the answer that was given but was unsatisfied.  Here's the
deal:  My Suzuki is waaay under powered.  But this can be a good thing, I
mean, you can blithely hotrod like crazy right in front of the cops, no
problem.  Go through the gears, engine screaming, exhaust wailing, scream
of tortured metal.. no..no.. just kidding.. anyway, a quick look at the
speedo shows you are just now reaching 40mph!  On a road trip with a slight
head wind, you may run at full throttle for hours.  Or it seems like hours.
 One might say the electronic carb drops  out of closed loop at full
throttle in order to richen the mixture a bit to give a larger safety
margin, maybe less possibility of detonation?  More cooling?  More power?
Well, as I think about it, since my tweaked engine has considerably more HP
than stock I have the same output at part throttle that the stocker does at
WOT.  And my engine holds together at high rpm WOT operation too.  So.. I
believe I am subjecting my engine to much greater thermal and mechanical
stress than a stocker ever achieves.  So.. I feel that at least for the
stock engine, the open-loop for WOT isn't needed.  And I wonder if I need
it for my engine.  Am I missing something here?

I am actively soliciting your input!

Thanks 
George Bearden



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