Fuel Pump Relay question

[Chris Hall]

Yeah....  I don't mind having a new set of wires to go with my new
Distributor cap and rotor though.  Well, if I can get the car to RUN
again, that is.  Can't believe it ran fine all week, and then started
again last night.

Still seems odd to me that the damn thing ran with 100% carbon coating
on each terminal.


But like I said, now when I pull the relay / fuse tray out and shake
it, the car dies almost EVERY time.  Died once when I reached down in
to the hole and tugged on one of the wire harnesses (which had like 40
wires in it...) so I'm thinking that it's maybe a wiring gremlin that
I'll never find.

Once I tugged on each wire and couldn't get it to stall.  Tried my
other Fuel Pump Relay, and after 2 minutes, the engine turned itself
off again and I couldn't get it re-started no matter how much I shook
the tray.


And again... jumping the fuel pump relay slots will make the pump run
non-stop, but there are 3 other pins that I imagine are ESSENTIAL for
the car to run, right?  I know the rev limiter is built in to this
relay, and I know this relay has control over spark since it sees the
coil and tach signals, etc... so I don't see how the engine could
possibly run without all 5 pins connected...



On 6/4/05, Jim Jordan <superba at comcast.net> wrote:
> Hi Chris,
> 
> Don't buy anything else without a reason;  seems to me the last fuel pump
> relay I got was $10, probably used, but it's worked well.  But don't start
> grabbing at straws.  You must go at this systematically or it'll drive you
> batty.
> 
> What is the exact model of your car?  I think 85 GT Coupe, but I'm not sure.
> I'll look in the Bosch manual and see what the check out procedure is for
> your injection system, but do confirm the model.
> 
> Cheers!
> 
> Jim Jordan
> 
> >  -----Original Message-----
> >  From: Chris Hall [mailto:badcomrade at gmail.com]
> >  Sent: Saturday, June 04, 2005 11:13 AM
> >  To: Jim Jordan
> >  Cc: Kent McLean; quattro at audifans.com
> >  Subject: Re: Fuel Pump Relay question
> >
> >  UPDATE!
> >
> >  Installed the new plug wires.  Even though the car was
> >  running FINE at idle last night in my parking spot (after
> >  stalling 2 times on the 20 min drive home), it wouldn't
> >  start.  Then it started, ran for 2 seconds, then shut off
> >  (as if I had turned the key to "off").
> >
> >  Eventually I took the cover off of the relay / fuse panel
> >  under the hood.  I put my hand on the fuel pump relay as I
> >  turned the key.
> >  EVERY time I turned the key, I felt the relay activate.
> >  Oddly enough, BEFORE I got the new cap and rotor (which it
> >  REALLY did need) I installed the relay WITHOUT the cover,
> >  and watched the electromagnetic switch.  It DIDN'T switch
> >  every time I turned the key.  NOW it is.
> >  I'm thinking it's SUPPOSED to do it every time... so there's
> >  something weird happening in that department.  Today I felt
> >  it clicking on and off AS the engine was cranking...
> >
> >  So I hold the key and let the engine crank for like 20
> >  seconds and then it finally fires right up and runs
> >  perfectly.  I then go and touch the fuel pump relay (or the
> >  tray), and it dies.  I get it started again and do nothing,
> >  and it dies a min later.  Then I get it started again and
> >  for the hell of it I push down on the WIPER relay, and the
> >  engine DIES.
> >
> >  *SO*  I think that YES, the fuel pump relay (although I
> >  can't spot ANY cracks in the solder) might not be "holding
> >  up", OR maybe (god I hope
> >  not) the TRAY in which all the relays sit has some kind of
> >  bad inner connection (ESPECIALLY if it's constructed like
> >  the REAR TAIL LIGHT bulb "trays" are, with the cheap metal
> >  held in place by melted plastic!!!).  I'm also guessing that
> >  maybe the relay (if it has cracks I can't FIND) might have
> >  been in the socket in just the -right- way to where the
> >  blades were torqued in a way that any intermittent
> >  connection was being held tight, and that's why it lasted
> >  ALL week until I was aggressively driving last night...
> >
> >  ONE MORE question.  Should the fuel pump relay be getting
> >  hot?  Mine is.  The car ran for 5 minutes and I pulled it,
> >  and it was hot.  Maybe it's getting SO hot that the magnetic
> >  field breaks down and the switch releases, shutting off the
> >  fuel and occasionally cutting back IN causing my BACKFIRE
> >  problem?  (A friend of mine use to shut the engine off in
> >  his truck as we were rolling down the street in gear, and
> >  then when he'd put the key back to "on" the thing would
> >  backfire and scare the hell out of people on the street....
> >  maybe my fuel pump relay is essentially doing the SAME THING
> >  and causing the occasional backfire when the car is stalling???)
> >
> >  By the way, I did lift the relay / fuse tray up and look at
> >  all the connectors on the bottom of it... they were all
> >  connected well and the wires look good.
> >
> >  Anyone had a bad "tray" ever?  Or should I be looking at
> >  BOTH of my relays (current and spare) being bad?  The back
> >  of the circuit board on the "spare" is all white and
> >  corroded so yeah not a good "spare" I guess.  But it used to
> >  work  lol.
> >
> >  Oh and one of the reasons I THOUGHT I eliminated the
> >  possibility of the fuel pump relay being the "culprit" was
> >  because I jumped the relay socket and heard the fuel pump
> >  run, but I STILL couldn't get the engine to run.  Is this
> >  because the car CAN'T run this way, because the other blades
> >  on the fuel pump relay have to be connected to "talk"
> >  to the ignition control module, coil, etc for the rev
> >  limiter function that's built in?  I always see people
> >  saying they carry a jumper in the car, but has anyone jumped
> >  just to two slots the wide blades go in and DRIVEN the car?
> >  Seems IMPOSSIBLE.  I could NEVER get my car to start with a
> >  paper clip in there, even though I could hear the fuel pump
> >  activate...
> >
> >  Maybe I should just go and pay the $125 or whatever for a
> >  NEW fuel pump relay.  If I could even FIND one in a
> >  junkyard, who knows how much better it'd be...
> >
> >  --
> >  Chris Hall
> >  badcomrade at gmail.com
> >  "making girls cry since 1974"
> >
> 
> 


-- 
Chris Hall
badcomrade at gmail.com
"making girls cry since 1974"