Injector Driver
Walter Sherwin
wsherwin at idirect.com
Sun Mar 7 01:49:54 GMT 1999
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Not really what I had in mind Ward, but thanks anyways! I want to use =
this PCM to drive 4 Rochester TBI injectors instead of two, in delayed =
channel synchronous TBI mode (picture a PCM driving a 900 CFM Holley). =
But, I would much prefer to drive the injectors as two series "pairs", =
directly via the PCM, as opposed to through the custom external 2-4 =
channel P&H driver box that I have at the current time.
If everything is perfect on my bench tester, I can in fact drive the two =
pairs of injectors with the GM 4/1 A drivers. However, the injectors =
are somewhat more sluggish, and in a real vehicle I would suspect that I =
could/would have problems with things such as low battery voltage, =
cranking conditions, and thermal soak. For this reason, I am looking to =
"boost" the injector current a little bit, effectively turning the 4/1 A =
drivers into say a 6/1.5 A drivers, or even something a fuzz higher.
After cannibalizing an old PCM, I think I have identified the =
appropriate peak to hold current "sense" resistors (.1 ohm), and the =
driver elements. I cannot find a cross reference for the driver, but I =
do see an "8A" stamped on its face, so I assume that it is rated for 8 =
amps?? Probably peak??
I'm going to hook this thing up and let it rip for a few days, to see =
what happens. I just thought I'd first see if anyone else had fiddled =
with such an idea, and what their experience had been. =20
Thanks;
Walt.
-----Original Message-----
From: Ward Spoonemore <spoonie at deltanet.com>
To: diy_efi at efi332.eng.ohio-state.edu =
<diy_efi at efi332.eng.ohio-state.edu>
Date: Saturday, March 06, 1999 4:32 PM
Subject: RE: Injector Driver
=20
=20
If you want more than 2 drivers your out of luck, there are only two =
drives on the board,=20
If you want 6 or 8 standard PFI injectors, GM uses 3 or 4 (6/8) in =
two batches. for PFI, the 94/95 PCM has a software mode switch for =
CPI/PFI and TBI. This is not to change the drivers but to change =
calibration functions. This is a much bigger thing than wiring up some =
injectors. This answer your question ?
Ward
-----Original Message-----
From: owner-diy_efi at efi332.eng.ohio-state.edu =
[mailto:owner-diy_efi at efi332.eng.ohio-state.edu]On Behalf Of Walter =
Sherwin
Sent: Saturday, March 06, 1999 5:29 PM
To: gmecm at efi332.eng.ohio-state.edu; DIY_EFI
Subject: Injector Driver
=20
=20
Has anyone played with the injector driver circuitry (two =
channel TBI - peak&hold) as found in the 16147060 PCM? This box is =
from a 91-93 light duty truck with 4L80E. I want to force the drivers =
to operate as either 6/1.5 A or 8/2 A units, instead of as conventional =
4/1 A units. =20
=20
I know that this is physically possible, by tailoring the two =
"current sense" resistors in the circuit, but I am wondering if anyone =
knows whether the rest of the components will stand up to this current =
abuse?=20
=20
Thanks;
Walt.
=20
=20
=20
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<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000 size=3D2>Not really what I had in mind Ward, =
but thanks=20
anyways! I want to use this PCM to drive 4 Rochester TBI injectors =
instead=20
of two, in delayed channel synchronous TBI mode (picture a PCM driving a =
900 CFM=20
Holley). But, I would much prefer to drive the injectors as =
two=20
series "pairs", directly via the PCM, as opposed to through =
the custom=20
external 2-4 channel P&H driver box that I have at the current=20
time.</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>If everything is perfect on my bench tester, I can =
in fact=20
drive the two pairs of injectors with the GM 4/1 A drivers. =
However, the=20
injectors are somewhat more sluggish, and in a real vehicle I would =
suspect that=20
I could/would have problems with things such as low battery voltage, =
cranking=20
conditions, and thermal soak. For this reason, I am looking to =
"boost"=20
the injector current a little bit, effectively turning the 4/1 A drivers =
into=20
say a 6/1.5 A drivers, or even something a fuzz higher.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>After cannibalizing an old PCM, I think I have =
identified the=20
appropriate peak to hold current "sense" resistors (.1 =
ohm), and=20
the driver elements. I cannot find a cross reference for the =
driver, but I=20
do see an "8A" stamped on its face, so I assume that it is =
rated for 8=20
amps?? Probably peak??</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>I'm going to hook this thing up and let it rip for a =
few days,=20
to see what happens. I just thought I'd first see if anyone else =
had=20
fiddled with such an idea, and what their experience had been. =20
</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>Thanks;</FONT></DIV>
<DIV><FONT size=3D2>Walt.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; PADDING-LEFT: =
5px">
<DIV><FONT face=3DArial size=3D2><B>-----Original =
Message-----</B><BR><B>From:=20
</B>Ward Spoonemore <<A=20
=
href=3D"mailto:spoonie at deltanet.com">spoonie at deltanet.com</A>><BR><B>T=
o:=20
</B><A=20
=
href=3D"mailto:diy_efi at efi332.eng.ohio-state.edu">diy_efi at efi332.eng.ohio=
-state.edu</A>=20
<<A=20
=
href=3D"mailto:diy_efi at efi332.eng.ohio-state.edu">diy_efi at efi332.eng.ohio=
-state.edu</A>><BR><B>Date:=20
</B>Saturday, March 06, 1999 4:32 PM<BR><B>Subject: </B>RE: Injector =
Driver<BR><BR></DIV></FONT>
<DIV><SPAN class=3D989155823-06031999><FONT color=3D#0000ff =
face=3DArial size=3D2>If=20
you want more than 2 drivers your out of luck, there are only two =
drives on=20
the board, </FONT></SPAN></DIV>
<DIV><SPAN class=3D989155823-06031999><FONT color=3D#0000ff =
face=3DArial=20
size=3D2></FONT></SPAN><SPAN class=3D989155823-06031999><FONT =
color=3D#0000ff=20
face=3DArial size=3D2>If you want 6 or 8 standard PFI injectors, GM =
uses 3 or 4=20
(6/8) in two batches. for PFI, the 94/95 PCM has a software mode =
switch for=20
CPI/PFI and TBI. This is not to change the drivers but to change =
calibration=20
functions. This is a much bigger thing than wiring up some =
injectors. =20
This answer your question ?</FONT></SPAN></DIV>
<DIV><SPAN class=3D989155823-06031999><FONT color=3D#0000ff =
face=3DArial=20
size=3D2></FONT></SPAN><SPAN class=3D989155823-06031999><FONT =
color=3D#0000ff=20
face=3DArial size=3D2>Ward</FONT></SPAN></DIV>
<BLOCKQUOTE>
<DIV class=3DOutlookMessageHeader><FONT face=3D"Times New Roman" =
size=3D2>-----Original Message-----<BR><B>From:</B>=20
owner-diy_efi at efi332.eng.ohio-state.edu=20
[mailto:owner-diy_efi at efi332.eng.ohio-state.edu]<B>On Behalf =
Of</B>=20
Walter Sherwin<BR><B>Sent:</B> Saturday, March 06, 1999 5:29=20
PM<BR><B>To:</B> gmecm at efi332.eng.ohio-state.edu;=20
DIY_EFI<BR><B>Subject:</B> Injector Driver<BR><BR></FONT></DIV>
<DIV><FONT size=3D2>Has anyone played with the injector driver =
circuitry=20
(two channel TBI - peak&hold) as found in the 16147060=20
PCM? This box is from a 91-93 light duty truck with=20
4L80E. I want to force the drivers to operate as either =
6/1.5 A or=20
8/2 A units, instead of as conventional 4/1 A units. =
</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>I know that this is physically possible, by =
tailoring=20
the two "current sense" resistors in the circuit, but =
I am=20
wondering if anyone knows whether the rest of the components =
will stand=20
up to this current abuse? </FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Thanks;</FONT></DIV>
<DIV><FONT size=3D2>Walt.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT =
size=3D2> </FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
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