Use an analog VOM. It's a lot easier to see a needle move than a display
flicker.

 

My memory ain't that good.

The ECU ground is often under/at the thermostat housing. Looks like in your
case G101 is actually at the firewall.

It's one of the battery cables, shown on pg 23-14 of the manual.

 The electrical system .pdf at this page

All I can suggest right now is to monitor the two-second continuity at the
Main Relay plug using an analog VOM. You should also get continuity at that
terminal when you crank the starter.

You may also want to chek all the voltage feeds from the ignition switch to
make sure the ignition switch is actually carrying steady current at all
its usual "key-on" live locations.

Does the Check Engine light illuminate during the first two-seconds of key-
on, then go off again right away?

Any codes stored in the ECU? Have you checked?

:  hgoldste@mpcs.com (Howard Goldstein) wrote in
:  news:1202582202.68680@news.queue.to:
:
: > On Sat, 09 Feb 2008 11:29:54 -0700, motsco_ <motsco_@interbaun.com>
: > wrote:
: > :  Howard Goldstein wrote:
: > : > Anyone ever repair a funky ECM by opening it up and cleaning up
: > : > any bad solder joints?  Will the ECM avoid sending fuel if it sees
: > : > something "wrong" at its sensors although there aren't any codes
: > : > stored?  Should I toss the ECM at this point?
: > : >
: > : > Long nauseating details and plea follow:
: > : >
: > :
: > :  --------------------
: > :
: > :  If you sit there with key in position II and nothing happens (no
: > :  fuel pump), smack the dash on the left side. If the fuel pump goes
: > :  GzzzzzzCLICK, the car will now start. They NEVER fail while the
: > :  engine is running because the vibration makes the bad solder
: > :  connection work enough.
: > :  Resolder or replace the relay.
: >
: > Hi, we chatted about this a few months ago.  Neither resolder nor
: > replace makes no difference.  Sitting there with the key on II for a
: > few minutes and it starts working.  The ECM isn't pulling the second
: > relay down :(
: >
:
:
:
:  Disconnect the Main Relay's plug from the Main Relay. Connect a multimeter
:  (set to Ohms) between the plug's Terminal 8 and a body ground.
:
:  Turn the key to "II". At thre same time as you turn the key, watch the
:  multimeter carefully. Do you get continuity for two seconds?

I will check this when I can reproduce it hopefully later today,
ambient is still a little too cool to reproduce long enough to test;
there's discernable (maybe a 1/4 second?) delay between going to II
and the fuel pump starting, and my DVM doesn't react that quickly.
Normally IIRC there's no delay at all.  

:
:  Have you checked the ECU ground at the thermostat housing? Have you checked
:  the engine grounds at the transmission housing and from valve cover to
:  shock tower?

Your memory is good: I tried to find a ground point near both radiator
hoses and for the life of me could not, nor do I see one at the
transmission housing (standard transmission) Is it an undocumented
ground?  The electrical system .pdf at this page
http://www.dhost.info/accordinfo/ with the grounds at .pdf page 15
looks like it's right out of my service manual.  I have G101 very
tight after crimping down harder on the two leads attached to it (G101
being on the intake manifold; p51 of the .pdf)  

I've re-secured all of the documented grounds in the engine
compartment and the one back by the fuel pump connector.  I haven't
checked grounds under the center console which has been off a couple
of times for radio installs.  I ohmed the two grounds at the ECM A23
and A24 connector to the vehicle body at the passenger kick
panel.

It seems like the only thing I haven't checked are the connections
through the injector resistors and IAC (p. 14 in the fuelemiss.pdf at
that link, p. 12 in the Honda service manual)

The valve cover<>shock tower<>body ground is good.

Disconnect the Main Relay's plug from the Main Relay. Connect a multimeter
(set to Ohms) between the plug's Terminal 8 and a body ground.

Turn the key to "II". At thre same time as you turn the key, watch the
multimeter carefully. Do you get continuity for two seconds?

Have you checked the ECU ground at the thermostat housing? Have you checked
the engine grounds at the transmission housing and from valve cover to
shock tower?

:  Howard Goldstein wrote:
: > Anyone ever repair a funky ECM by opening it up and cleaning up any
: > bad solder joints?  Will the ECM avoid sending fuel if it sees
: > something "wrong" at its sensors although there aren't any codes
: > stored?  Should I toss the ECM at this point?
: >
: > Long nauseating details and plea follow:
: >
:
:  --------------------
:
:  If you sit there with key in position II and nothing happens (no fuel
:  pump), smack the dash on the left side. If the fuel pump goes
:  GzzzzzzCLICK, the car will now start. They NEVER fail while the engine
:  is running because the vibration makes the bad solder connection work
:  enough.
:  Resolder or replace the relay.

Hi, we chatted about this a few months ago.  Neither resolder nor
replace makes no difference.  Sitting there with the key on II for a
few minutes and it starts working.  The ECM isn't pulling the second
relay down :(

--------------------

If you sit there with key in position II and nothing happens (no fuel
pump), smack the dash on the left side. If the fuel pump goes
GzzzzzzCLICK, the car will now start. They NEVER fail while the engine
is running because the vibration makes the bad solder connection work
enough.
Resolder or replace the relay.

'Curly'

Anyone ever repair a funky ECM by opening it up and cleaning up any
bad solder joints?  Will the ECM avoid sending fuel if it sees
something "wrong" at its sensors although there aren't any codes
stored?  Should I toss the ECM at this point?

Long nauseating details and plea follow:

Recap: 94 Accord with the classic main relay (PGM-FI) symptoms (no
fuel pump sound for 2 seconds as required when starting, check engine
light on, can't start) with a twist: It only fails in a cold car when
ambient is around above about 70F/27C, *and* leaving the key in the II
(IGN) position for anywhere from 1 to 4 minutes has always allowed the
second relay and then the fuel pump to kick in, CIL goes off and we're
off.  Never a problem while driving, and if the engine is warm it's
never a problem starting.  It also isn't a problem when the entire car
has cooled to the low 60s/low 20s F/C or below.  Cranking it doesn't
help.

What I've done: I've verified there's no 12v back at the fuel pump
when this happens but for good reasonI've measured battery voltage
at the relay pins 6 (good) and 1 (bad) and back at the ECM A25&B1 and
A7 (these are the connections to the relay) where it's good and bad
(both at Vbatt).  I've jumpered the service connector and the CIL
stays on all the time.  I've got good grounds at the ECM A connector
and the PGM-FI.

What seems to be busted: WTF is up with my ECM?  The skiz show the
fuel pump relay in the PGM-FI won't close unless the ECM pulls down
its A7 (which is PGM-FI pin 1).  It doesn't pull it down, not unless
the car is left in II/IGN for a couple of minutes under the conditions
above.

Some specific questions:

- What else am I missing?  

- Does the ECM look for other things, a sensor in a sane range or
something other than battery voltage coming off of PGM-FI 6, before
it'll turn on the fuel pump for the 2 seconds?

- Is it worth cracking open the ECM to reheat any obviously flakey
solder joints?  Can the ECM be cracked open easily?

- Anyone have a compatible ECM they'd loan me to do a swap check if
I've ruled out everything else?