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Topic: Fuel pump / electrics (Read 10569 times) |
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TiberiuS
Senior Member
Ex. 1996 2.3 Ultima - RIP P789 KHJ
  
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Re: Fuel pump / electrics
« Reply #20 on: May 21st, 2007, 4:41pm » |
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Guys, I always understood the priming burst was timed and not pressure sensitive 
Any excess pressure would be relieved by the FPR normally - BUT, some pumps do have an overload feature in case the FPR or part of the system becomes blocked, a long shot but are the lines and filter clear?
Most cars are designed to work with an amount of positive pressure in the tank...IMO if you find any pressure in the tank it'll be positive rather than negative and as SD says, running with the cap off would eliminate it anyway.
Check for signal to the relay coil, if there's a stable voltage going to the coil you're looking for a loom/earth/switch fault, if the coil isn't getting the voltage you're looking on the ECU side of things.
Hope this helps some.
Regards, Bruce.
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Bruce - '07 Jaguar XKR coupe, '95 Jaguar XJ Sport 4.0, '82 Ford Capri 2.0 Ghia, '15 Honda Civic (sloooooww..)
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Dave2302
Senior Member
2006 Mercedes S55 AMG, Retired Barefoot Waterskier
Posts: 1119
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Re: Fuel pump / electrics
« Reply #21 on: May 21st, 2007, 5:02pm » |
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LOL Bruce
Quote:| Guys, I always understood the priming burst was timed and not pressure sensitive |
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Dave Wrote:- Quote:then monitor the signal to the fuel pump relay from the ECU.
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Bruce Wrote:- Quote:Check for signal to the relay coil, if there's a stable voltage going to the coil you're looking for a loom/earth/switch fault, if the coil isn't getting the voltage you're looking on the ECU side of things.
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I bet you first had this on a V12 Jag LOL, cos I know I did 
Regards Dave
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Dave "The 'ol Bear" ex Footer !
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TiberiuS
Senior Member
Ex. 1996 2.3 Ultima - RIP P789 KHJ
Posts: 2257
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Re: Fuel pump / electrics
« Reply #22 on: May 21st, 2007, 5:27pm » |
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Quote:| I bet you first had this on a V12 Jag LOL, cos I know I did |
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LMAO
You read my mind Dave
When I got the V12 it had a 'minor fuel pump issue' on one of the tanks...i.e. woudn't start 
Spent ages trying to work it out, old Lucas weren't that bad
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Bruce - '07 Jaguar XKR coupe, '95 Jaguar XJ Sport 4.0, '82 Ford Capri 2.0 Ghia, '15 Honda Civic (sloooooww..)
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Highlander
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13 Scorpios, XR4x4, Suzuki SJ413 for off road :)
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Re: Fuel pump / electrics
« Reply #23 on: May 21st, 2007, 6:48pm » |
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We have already tried the ECU change, still did exactly the same.. will try the bypass of the fuel cut off and the direct 12v to the pump and report back
Stuart
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on Oct 17th, 2011, 12:35pm, Simmo wrote:I give up ! Too much for an old boy!  |
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Dave2302
Senior Member
2006 Mercedes S55 AMG, Retired Barefoot Waterskier
Posts: 1119
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Re: Fuel pump / electrics
« Reply #24 on: May 21st, 2007, 8:13pm » |
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Hi Stuart,
Well, having already tried the ECU you are doing exactly what I would, so my moneys on the cut off switch or wiring at fuel pump relay (fuse box) end. 
Bruce... that V12 fault is so common, I've fixed loads of them, but like you the first one took me ages to figure out
Regards Dave
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Dave "The 'ol Bear" ex Footer !
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tintin
Full Member
I'm a YaBB newbie!
Posts: 592
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Re: Fuel pump / electrics
« Reply #25 on: May 21st, 2007, 8:15pm » |
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grandma and eggs probably......
could it be the pats disabling the car?
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'95 Cosworth Ultima
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Highlander
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Re: Fuel pump / electrics
« Reply #26 on: May 21st, 2007, 10:50pm » |
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Tried the above, got the car running perfectly for 5 mins then it cut out slowly as if a petrol supply was cut.
Couldn't restart it, can smell petrol at the exhaust but the fuel pump still only pumps a small amount then stops.
when the car is sitting with the ignition on the fuel pump can be heard to click every 30 seconds or so.
PATS is working, showing no code
Will test the supply next
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on Oct 17th, 2011, 12:35pm, Simmo wrote:| I give up ! Too much for an old boy! |
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Dave2302
Senior Member
2006 Mercedes S55 AMG, Retired Barefoot Waterskier
Posts: 1119
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Re: Fuel pump / electrics
« Reply #27 on: May 22nd, 2007, 9:02am » |
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Fuel Pressure Regulator ?
think it needs a look at some live data when it's running, like ltft's etc, perhaps put a fuel pressure gauge on the rail......
Regards Dave
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Dave "The 'ol Bear" ex Footer !
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Highlander
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Re: Fuel pump / electrics
« Reply #28 on: May 22nd, 2007, 11:38am » |
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would try that if we could get it running
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on Oct 17th, 2011, 12:35pm, Simmo wrote:| I give up ! Too much for an old boy! |
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TiberiuS
Senior Member
Ex. 1996 2.3 Ultima - RIP P789 KHJ
Posts: 2257
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Re: Fuel pump / electrics
« Reply #29 on: May 22nd, 2007, 12:12pm » |
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Stuart. Have you (I know this is naughty, don't try it at home  ) bridged the connectors for the relay terminals in the fusebox socket? Are you getting 12v to the pump terminals or at least to the relay?
If the ECU is cutting the supply off for some reason, bridging the 12v supply should send 12v to the pump all the time...and safer than rigging a 12v rail directly to the pump.
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Bruce - '07 Jaguar XKR coupe, '95 Jaguar XJ Sport 4.0, '82 Ford Capri 2.0 Ghia, '15 Honda Civic (sloooooww..)
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Spannerdemon
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Re: Fuel pump / electrics
« Reply #30 on: May 22nd, 2007, 12:28pm » |
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I would now be working along the lines of bypassing the fuel tank altogether if you can. I still suspect a blockage, and the tank itself must now seem highly suspect.
Going back to one of my previous posts on this, IF someone has deliberately put sugar in the tank, (and believe me people DO do it), then it would explain the whole problem. Petrol will not seep through sugar. It forms a very effective blockage, and produces exactly the problems that you are experiencing.
I obviously hope this isn't the case, but I think you are now looking at something out of the ordinary here and I think the tank is going to have to come off
PS. How's business going Stuart? Hope it's taken off well for you.
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Neil W
Full Member
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Re: Fuel pump / electrics
« Reply #31 on: May 22nd, 2007, 4:15pm » |
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Hi,
My money is on the in-line fuel filter which, on the Cosworth, is just forward of the fuel tank on the nearside adjacent to the rear wheel drive. I bet it hasn't been replaced in years; mine hadn't and was full of muck. Easy to replace as it clips onto the fuel line.
Yippee!! Full member at last; taken 2 years  .
Cheers,
Neil W.
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1998 Scorpio Ultima Cosworth facelift saloon, reg S896VOG. Sold Feb 2010. Now own Mercedes-Benz E320 CDi.
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mike
Junior Member
1996 Cosworth
Posts: 63
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Re: Fuel pump / electrics
« Reply #32 on: May 22nd, 2007, 7:24pm » |
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Maybe a little far flung but easy to check:
As Alastair pointed out to me there is a third wire (Black/Red) which connects pin 8 of the ECU to the inertia switch (see 29-07-011 in http://www.carsoft.ru/avtorepair/sierra/engcntrl23m.pdf).This wire is normally unconnected but if the switch trips it gets grounded via the fuel pump motor winding: the ECU is therefore informed that a collision has occurred. I don't know for sure what it does then, but I should think it would kill the ignition so the engine does'nt keep running on residual fuel rail pressure.
Now suppose this Black/Red wire gets (intermittently) grounded either in the loom or inside the (already suspect) inertia switch...This would tally with the engine dying and the exhaust smelling of petrol.
With the above in mind I would:
1) disconnect the ECU and the inertia switch multiplug
2) test between the Black/Red wire and ground with an ohmeter
If less than "infinite" resistance, game over.
Else:
3) connect a strap on the multiplug between the two violet/orange wires (leaving the switch out), reconnect ECU and test.
My money is still on the d..d red button!
Cheers,
Mike
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Dave2302
Senior Member
2006 Mercedes S55 AMG, Retired Barefoot Waterskier
Posts: 1119
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Re: Fuel pump / electrics
« Reply #33 on: May 22nd, 2007, 7:36pm » |
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With all they have tried, the " ****" Red Button is a prime suspect
Regards Dave
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Dave "The 'ol Bear" ex Footer !
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Alastair
Full Member
2.3 Ghia X & MGB Roadster
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Re: Fuel pump / electrics
« Reply #34 on: May 22nd, 2007, 7:46pm » |
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Thanks Mike
Just an update. Further to Highlander's post last night
( Stuart your mobile is switched off) Tonight at 7.30 the car started first turn and ran for 11 minutes (moved out and thankfully back into the drive) and then slowly died and would not restart.
During the 11 minutes it either sat rock steady at 850rpm or would rev through the whole range up to and briefly 5000 revs (smoothly). No doubt having sat it would do the same tomorrow. ?
ALastair
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Snoopy
Administrator
Very old.BAD tempered and missing friends.
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Re: Fuel pump / electrics
« Reply #35 on: May 22nd, 2007, 7:48pm » |
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Does sound as though something is gettin HOT electrically and then breaking down.. Are you sure its NOT the relays? But I am sure ther eis some one who will give a definative answer!
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TiberiuS
Senior Member
Ex. 1996 2.3 Ultima - RIP P789 KHJ
Posts: 2257
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Re: Fuel pump / electrics
« Reply #36 on: May 22nd, 2007, 7:54pm » |
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Mike, that connects to pin 8 of the CCM not the ECU. That's done to release the central locking I believe, not to kill the engine...engine would die within a second or so if there was no pressure.
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Bruce - '07 Jaguar XKR coupe, '95 Jaguar XJ Sport 4.0, '82 Ford Capri 2.0 Ghia, '15 Honda Civic (sloooooww..)
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Spannerdemon
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Re: Fuel pump / electrics
« Reply #37 on: May 22nd, 2007, 8:13pm » |
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It's certainly going to be very interesting to see the 'culprit' for this one.
I know when my wife's Ignition Amplifier went on her MR2 last year, it took 7 garages (including 2 Main Dealers with all the diagnostic gear), myself, two auto electricians and several very helpful MR2 owners from the MR2 forum/MR2 owners club, 7 weeks to discover the cause, by which time we were all almost tearing our hair out.
The silly thing is, it was exactly the same problem. Running for 2 to 3 seconds, and then.....Zilch! 
Car's..........Don't we just love 'em!!
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mike
Junior Member
1996 Cosworth
Posts: 63
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Re: Fuel pump / electrics
« Reply #38 on: May 22nd, 2007, 8:44pm » |
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Right you are Bruce! There go my ramblings down the drain...
I guess there'll be crow on the dinner menu tonight 
Cheers, Mike
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Highlander
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Re: Fuel pump / electrics
« Reply #39 on: May 22nd, 2007, 9:31pm » |
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It seems to start after sitting overnight or when its not been tried for a while.
The relays all click fine and have been swapped with known working replacements
It definitely sounds like fuel startvation when it cuts out.. perfect idle..slight cough.. uneven running then dies.. after 11 minutes today and roughly the same last night
I sounds like the fuel is slowly being restricted until the engine stops then it will not restart..
I think we'll have another look at the fuel system, filter etc possibly even connecting an external tank/pump as a fuel supply.
I dont have access to a (working) 2.3 (sorry Alastair)  so could someone with a 2.3 possibly disconnect their fuel line beside the manifold and see if the fuel pumps continuously when the ignition is on?
This one pumps for a split second then stops.
We did try releasing the fuel filler cap incase the vaccum was building up and restricting the flow but it made no difference
Also, remember the fuel pump clicking every 30 seconds or so when the ignition is on? does this suggest a leak/pressure loss in the system somewhere maybe? like its trying to top it up?
any more ideas??
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on Oct 17th, 2011, 12:35pm, Simmo wrote:| I give up ! Too much for an old boy! |
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