RE: IML: '81 EFI IMPERIAL won't start

["Dick Benjamin" <dickb@xxxxxxxxx>]

OK, it appears that either the power amplifier or the vapor purge latching
transistor has failed - so the power module is going to have to be repaired.

I think your best bet is to get another power module and swap them out, but
save the old one because it can be repaired.  I used to repair these but
there was not much call for it and I've stored all the equipment I need to
do it - and I don't have any plans to get into it again.  Maybe someone else
in the club with an electronics background will volunteer - I'd be happy to
provide some guidance. In the mean time, contact Bob Baker to see if he has
any more of the ones we tested/repaired a few years ago.

Bob is at baker-michaels@xxxxxxx

Your in-tank pump pressure is a bit low, but I think the car should run OK
that way - and your gauge could be off that far anyway, unless it is a
precision gauge.

Dick Benjamin


-----Original Message-----
From: mailing-list-owner@xxxxxxxxxxxxxxxx
[mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of ryan walker
Sent: Thursday, August 03, 2006 5:36 PM
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: RE: IML: '81 EFI IMPERIAL won't start


Hello!
I checked to make sure there was 12-volts at the ASDM, and there was.
I bypassed pin 2 & 3, and in-tank fuel pump ran with key on.  So I
checked the 23 volt power supply, and there was 22.83 at the air flow
meter connector, the throttle position sensor, and pin 3 of the power
module.  
I then grounded the fuel pressure switch, and turned the key on. 
There was no spurt of gas.  When I checked the voltage at the control
pump, ASDM bypassed, key on, plugged in, I had zero volts.  Unplugged
I had 4.75 to 5.08 volts.
I also checked fuel supply from the in-tank pump, it was 11.5 PSI.
With good flow.
Thanks everyone for your input.

Ryan Walker
---- Original Message ----
From: dickb@xxxxxxxxx
To: mailing-list@xxxxxxxxxxxxxxxx
Subject: IML:  '81 EFI  IMPERIAL won't start
Date: Tue, 1 Aug 2006 21:38:39 -0700

>OK, that eliminates a whole pile of things.  
>
>First, make sure that 12 volts is getting to the power module as
>follows;
>bypass the ASDM by putting a temporary wire from pin 2 to pin 3 on
>the ASDM
>- this will put 12 volts on the power module input and run the
>in-tank fuel
>pump any time the key is on, regardless of the other logic inputs to
>the
>ASDM. 
>
>Next, check the 23 volt power supply output.  Look on any one of the
>following places:  The center pin of the air flow meter connector, or
>the
>pink wire on the throttle position sensor, or pin 3 of the power
>module.
>There should be 23 volts on the above points. 
>
>Be very sure not to short the 23 volts to ground - that is the most
>common
>failure point in these cars, and the most easily caused by poking
>around the
>system.
>
>If the voltage is not 23 volts within about 1/2 volt or so, your
>power
>module has failed and we'll have to find you a new one.
>
>If there is 23 volts at the power module output, turn the key off and
>then
>short the wire which goes to the fuel pressure switch to ground, then
>turn
>the key on again momentarily, while you watch the voltage on the
>control
>fuel pump input - you should see a momentary surge of 12 volts or so
>on that
>point, and there should be a spurt of gas from the nozzles.
>
>If there is a momentary surge of 12 volts on the control fuel pump,
>but
>still no gas at the nozzles, we need to check the fuel pressure at
>the
>control fuel pump inlet. It should be 13 PSI, within 1/2 PSI or so. 
>The
>easy place to check this is at the filter outlet under the car, just
>under
>the passenger door hinge post.
>
>If there is still no drive to the control fuel pump, we'll have to
>investigate the power module amplifier function and the logic which
>controls
>it, but let's not get too far ahead of the story.
>
>Dick Benjamin
>
>-----Original Message-----
>From: mailing-list-owner@xxxxxxxxxxxxxxxx
>[mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of ryan walker
>Sent: Tuesday, August 01, 2006 5:23 PM
>To: mailing-list@xxxxxxxxxxxxxxxx
>Subject: IML: Info on '81 EFI IMPERIAL
>
>The info on this car is, that I reinstalled the air cleaner, the car
>would just crank.  I took the air cleaner lid off, poured a little
>gas down the throttle plates, put lid back on, car started, ran for a
>second, and died. So it seems the problem is lack of fuel. 
>Any and all suggestions are welcome and greatly appreciated.  
>
>Thank you,
>Ryan Walker   
>
>
>
>
>-----------------  http://www.imperialclub.com  -----------------
>This message was sent to you by the Imperial Mailing List. Please 
>reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be 
>shared with everyone. Private messages (and attachments) for the
>Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx
>To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm
>




-----------------  http://www.imperialclub.com  -----------------
This message was sent to you by the Imperial Mailing List. Please 
reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be 
shared with everyone. Private messages (and attachments) for the
Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx
To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm





-----------------  http://www.imperialclub.com  -----------------
This message was sent to you by the Imperial Mailing List. Please 
reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be 
shared with everyone. Private messages (and attachments) for the
Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx
To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm