limp 7730

[Programmer]

'Bout the only thing I can think of is that the fuel pump relay is
backspiking the PCM at key off ? The OP switch keeps the circuit live for
about that 3 second long (I think)...

Lyndon
----- Original Message -----
From: <Fisystems at aol.com>
To: <gmecm at diy-efi.org>
Sent: Wednesday, May 09, 2001 8:00 AM
Subject: Re: limp 7730


> AUJP GM prom erased and reprogramed. I have unplugged and plugged it in a
> dozen times. Seems to be okay. I also swapped the ECM, distributor, plugs,
> plug wires and the map sensor.
>
> <<Are you using a 1227730 ecm or one of the updated units. I've had a ton
of
> trouble with the old 730's.
> AL>>
>
> One of the ECM's is a reman unit and the other old stock. How can you tell
if
> its an updated one?
>
> << Is this with a stock (eprom soldered in) memcal, or something with a
socket
>  on it?  If it's socketed, could be a connection problem.
>
>  -> Bob Valentine
>  -> bob at tecmark.com
>
>
>  At 11:36 PM 5/8/2001 EDT, you wrote:
>  >
>  >Strange problem for me but, maybe you guys have had or heard of this.
I'm
>  >running a 7730 on a L98 TPI race engine. Dyno numbers 510tq 465 hp. The
>  >problem is the thing will go into limp mode every time I shut it off and
> try
>  >to restart it. When it restarts it's in the limp mode. No communication
> with
>  >scanner and base timing with static pulse width at the injectors. It
will
>  >stay that way until I disconnect the battery and reconnect it. I can
then
>  >start it and it will run fine, no codes, close loop and good power. I
have
>  >checked the power wires and grounds and all seems to be in order. I
moved
>  the
>  >battery power to switched power so that I can shut it off and than
restart
>  it
>  >without having to disconnect and reconnect it. With it wired that way if
> the
>  >engine stalls and the power switch is still on, I can watch the scanner
> lose
>  >communication after about three seconds. If I just hit the start button
>  >without turning the power off and back on it's in the limp mode. Any
ideas?
>  >
>  >Thanks
>  >
>  >Ken >>
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