TPS and RPM only?

[Tom Cloud]

>     I'm glad this came up. I'v been looking for a first step to adapt an 
>     older engine to EFI and TBI is something to consider although it's not 
>     discussed to often on this list...
>     
>     I've been doing some research on the Holley ProJection, mainly in the 
>     mail archives and at Holleys Website. Holley has a BBS which mainly 
>     seems to work as a department for complaints for more or less 
>     frustrated ProJection users. 
>     
>     I have a 225 slant 6 and thus the 501-2 kit for 258" Jeep is the 
>     obvious choice. This unit can (according to Holley) be adjusted (via 
>     control knobs?) for:       Idle
>                                Accelerator pump
>                                Mid.range
>                                Power
>                                Choke
>     
>     The fuel pump pressure can also be adjusted. As I understand, it uses 
>     only TPS and RPM sensors.
>     
>     Is this the same set-up you use? I'm asking because according to all 
>     the complaints on the mentioned BBS, there are a lot of users that are 
>     extremely unhappy with the system, being unable to adjust it properly 
>     and getting no help from Holley as it seems. I was even offered to buy 
>     a hardly used set-up from a furious user...
>     
>     Have you (or any one else on the list) had any problems to adjust this 
>     system? Can the problems likely be explained by the fact that there is 
>     no MAP sensor (i.e. "load sensor") on the ProJection.
>     
>     Any tips on this are interesting for me and highly appreciated.
>     
>     mike.olsson at eu.pnu.com

Here's why I would go ProJection again .... it's half the cost of
anything else (~$600), it works (though not perfectly), and
I think it would still be faster for me than trying to retrofit
a Ford EEC-IV to a Ford vehicle (unless it was an identical
configuration, say an Early 302 Mustang with same drivetrain
that I wanted to update to EFI).  I'm not clear whether MAP
or EGO is the next logical step in the feedback circuit ????

Yes, this is the same system I use.  I got some e-mail from
some "furious users" wanting me to join a class action suit
against Holley.  Summit dropped the version of ProJection I
use, telling me they had too many complaints.  My research
tells me many of the people who did the conversion were not
prepared, didn't know enough, or weren't careful enough.

The hardest part, to me, was getting the fuel intake and return
lines in correctly.  Next, was the wiring for the unit and for
the fuel pump relay.  [The ProJection box outputs two voltages
to the relay for high and low demand apps, but Holley notes that
that circuit can control a relay for the pump.  This removes the
high current drive demands from the controller box and lets it
run cooler.]  Oh, I forgot .... finding a place for the control
box .... I made a plate for it and strapped it to my steering
column in my Bronco.  It's out of the way and I can reach the
knobs while "in flight" (though I can't see them).

The TBI bolts on like a carburetor (I don't like the *way*
it bolts on, but it's a minor inconvenience).  There is
a really cheesy little plastic hootis that goes between
the air cleaner and the TBI that's real flimsy.  And,
the connectors to the injectors are crummy.  But, all-in-all,
I think it's a good deal for $600.  I mean, everything's
there, except the fuel line.  I added a "pre-pump" and
a "pre-filter", because that's what I read recommended
from some book I bought about the ProJection system.

Once I had it hooked up, set all the pots to center, it fired
right up.  I had it tuned and running in less than 5 minutes!
I've probably got 10,000 miles on it.  Occasionally, I get
frustrated because it seems to not be as peppy as it was
the week before, or it doesn't want to run right when it's
cold.  I don't understand those problems, and those occasional
inconsistencies would make it difficult to work as my wife's
daily driver, but it's okay for me.

My calls to Holley tech line were answered okay (not great,
just okay), but they were answered.  Of course, being on
hold for a long time is not pleasant.

Tom Cloud <cloud at peaches.ph.utexas.edu>