Using TBI on moded 5.7

[Programmer]

Disconnect your TPS. Measure outside terminals with your DVOM with the key
on. You should measure 4.8 to 5.0 volts. You can check your sensor grounds
by voltage drop method...ground to ground. Any amount over 200mV is a bad
ground.
Re-attach your PCV. If you've got 30 counts with no PCV and your idle is
correct, I think you've got a vacuum leak.
-----Original Message-----
From: Mike Vannorsdel <vannorsdel at rmi.net>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: November 8, 1999 2:19 PM
Subject: Re: Using TBI on moded 5.7


>The voltage going to the TPS is 4.5v.  But for some reason at WOT it only
reads
>3.8v.  I'm pulling 20" vacuum.  I didn't reattach the PCV, is this a
problem?
>I'm getting 30 counts on the IAC.  From what I can tell is the TPS is
causing
>the rich idle and the hesitation.  Is there a special way to "autozero" the
TPS
>or just reset all of the sensors?
>
>Programmer wrote:
>
>> Check your engine grounds, and especially those that are sensor related.
The
>> TPS voltage "low" at WOT is a clue.  The TPS is "autozero" type--spec
should
>> be closer to .45 volts. Make sure the throttle plate is at rest when you
>> turn on the ignition. Like Shannon said, make sure the throttle plate is
>> opening fully. The TPS ground is also shared by the MAP sensor--and don't
>> overlook your EGR valve which could be leaking. If you have a scan tool
note
>> the IAC counts. Anything below 25 (and a higher than normal idle) with a
>> fully warmed up engine "indicates" a vacuum leak or wrong PCV valve.
>>
>> Pay close attention to what the BL numbers are doing--they're the self
>> diagnosing parameters you can use to see what the computer is commanding
at
>> the fuel end of things...
>>
>> Lyndon IPTECH
>> -----Original Message-----
>> From: Mike Vannorsdel <vannorsdel at rmi.net>
>> To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
>> Date: November 8, 1999 12:06 AM
>> Subject: Re: Using TBI on moded 5.7
>>
>> >Well the problems I'm facing now is erratic idle and poor throttle
>> response.  I
>> >have tried the timing at 0 and 10 with a little added power at 10 but no
>> fixes
>> >to the problems.  The TBI is used and I'm not sure on the condition of
>> IAC(it
>> >does work but I don't know how well).  The TPS reading at idle is .78v
>> which is
>> >high and at WOT it's 3.8v which is low.  I replaced the TPS and now have
>> added a
>> >hesitation, voltage is the same.  At idle the injectors seem to be
giving
>> way
>> >too much fuel(it almost puddles on the throttle plates).  The MAP is new
>> and
>> >there are no vacuum leaks.  The TPS doesn't seem adjustable.  I'm not
sure
>> if
>> >the problem is TPS, injector, or both.  The engine cruises fine.  I'm
just
>> >looking for smooth running and have faced the fact that I won't be able
to
>> get
>> >max performance from it with the stock ecm.  I have the data on the
engines
>> best
>> >performance level but am unfamiliar with prom programming and don't have
>> the
>> >equipment.
>> >
>> >CSH-HQ wrote:
>> >
>> >> If you really want it right, probably will take a chip (prom).
>> >> Might get by with jacking the timing via the dist/playing with fuel
>> >> pressure, but those are bandaids, but will tell you how far off you
are,
>> to
>> >> a degree.
>> >> Try reading tuning.txt, tuning.doc, and programming 101, then check
back,
>> and
>> >> you'll then have more of an understanding of where you are/what you
have
>> to
>> >> do.  The related material is off of the home page to FTP, and
projects.
>> >> Grumpy
>> >>
>> >> >No relation.  I don't have any reprogramming eqip either.  I'm aware
of
>> the
>> >> >needed settings for timing and fuel with the changes but really have
no
>> way
>> >> >to change the ecm.  I was just looking to see if the TBI at stock
>> settings
>> >> >will be a problem or not.
>> >> >
>> >> >CSH-HQ wrote:
>> >> >
>> >> >> You any relation to Kevin?.
>> >> >> Do you have a prom burner, or related equipment?.
>> >> >> Have you any prom burning experience?.
>> >> >>
>> >> >> More fuel, timing adjustments sound likely.
>> >> >> Have you read programming 101,
>> >> >> do you have a 1227747 ecm?.
>> >> >> Grumpy
>> >> >>
>> >> >> >I have a '91 K1500 with the 5.7 TBI.  I have just rebuilt the
engine
>> and
>> >> >> >made a few changes.  I have raised the compression to 9.5 and
added a
>> >> >> >CompCams XE250(250/260).  What, if any, changes should be made to
the
>> >> >> >timing and TBI to work well with the changes?
>> >> >> >
>> >> >
>> >
>