5ktq electrical problems update (not fixed)

[Jim Green]

> 1) When my laptop shows 12.8v at the EFI the engine
> starts missing.
> 2) When it shows 12.6v the engine will stall unless
> held above 75% throttle
> in which case it holds at 3k rpm.
> 3) When the battery voltage is 12.7v (fully charged,
> car off) the charging
> voltage is 13.8v, battery @ 12.00v yeilds charging
> voltage of 13.2v +/-
> 0.1v.
> 4) Injector + comes from the ignitioin switch
> run/start terminal, - through
> EFI ECU.
> 5) EFI ECU is very well grounded.
>
> Now my ideas(even the far fetched ones):
> 1) My EFI ECU may be done messed up. In the process
> of building another for
> another car, will test tomorrow.

Can you monitor the injector PW to see if you get a
drop in fuel delivery?

> 2) Huw may be right that I need the Huwlett Packard
> (had to do it sorry :-},
> never say that again I promise) needs its own fused
> power supply right of
> the ignition switch (draws no more then an amp or
> two).

Always a good idea, I have a relay controlling a bunch
of stuff right there.

> 3) Spark color may be a rediculous way to check the
> ignition (though it
> seems reasonable and has been a tell tale on other
> dead cars I kinow of) and
> I'm still looking at the same problem.

I tried that recently, all I accomplished was a few
good zaps.

> Likely non-problems:
> 1) The brand new GM intake air temp sensor and the
> GM coolant temp sensor
> 2) Wiring to the above sensors
> 3) All 3 Mac-11s being dead
> 4) Engine grounding
> 5) EFI ECU grounding
> 6) Ignition switch (brand spankin new)


Hmm, I don't see the coil and power stage in there.
I've had bad coils do some really strange things.
Can't remember if you've swapped it yet.  I've driven
my car on just the battery down to about 9 volts
before the ignition starts to cut out.  My bet is that
your coil is on the fritz.

=====
Jim Green
'89 90tq 034EFI Stage II
http://www.mswanson.com/~jgreen/car_home.html

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