Fuel issue

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anucat
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Fuel issue

Post by anucat » 09 Mar 2014, 13:46

Hi all I suspect I need a new fuel pump but not sure. Fired up yesterday and as much as I pumped the pedal I couldn't keep the engine going for longer than a few seconds. Today worse. It starts, catches and dies. When I turn on the ignition I don't hear the hum of a servo or pump (though not entirely sure I ever did)

Where is the pump? I looked in the rear footwells but couldn't see a cover. And which fuse is it? Is it likely the pump or is there a sensor that fails?

Any expertise gratefully received.

If I can get it going I think I'm going to have to sell it. With two young kids I don't really have the time to diagnose and fix faults!


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anucat
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Re: Fuel issue

Post by anucat » 09 Mar 2014, 23:19

Actually just googling the issue I'm wondering if it's a bad ignition coil. Ever since buying the car last year it has idled badly and not been a great starter. I've replaced alternator, starter motor and battery since buying it, I can't think what else would be a fault common to both poor idling, an occasional failure to fire on ignition, and now this - firing up and dying immediately. I've only ever burnt out a fuel pump once on a car and that was when I ran the tank dry on my XM.

I see Ebay is selling CX ignition coils for as little as £12. How many are there on a CX 25 RI Familiale 1985?


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citronut
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Re: Fuel issue

Post by citronut » 10 Mar 2014, 14:40

what engine/fuel system is this car,
carb or injection

if the later the fuel pump is attached the the rear sub frame and i belive there is a pimp relay under one of the headlamps, N/S i rhink
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Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years

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Re: Fuel issue

Post by Northern_Mike » 10 Mar 2014, 14:48

citronut wrote: i belive there is a pimp relay under one of the headlamps, N/S i rhink


Those filthy French!
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anucat
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Re: Fuel issue

Post by anucat » 10 Mar 2014, 14:58

Injection but no turbo.cx25 RI. When I get a chance I'm going to clean the connections, starting with the one in the driver's footwell. I think the relay under the headlamp is referred to as the Big Blue relay and can sometimes play up. I read elsewhere that there's sometimes a dodgy earth near the battery on the wheel arch too.

I've not had much experience with auto electrics so am going to unplug and clean as many plugs and relays as I can find. Not very methodical but there you go.




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citronut
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Re: Fuel issue

Post by citronut » 11 Mar 2014, 14:52

Northern_Mike wrote:
citronut wrote: i belive there is a pimp relay under one of the headlamps, N/S i rhink


Those filthy French!



and you have to watch that Scarlet with her pimp and nails :roll: :roll: :-D :rofl2: :rofl2: :wink:


anucat wrote:I've not had much experience with auto electrics so am going to unplug and clean as many plugs and relays as I can find. Not very methodical but there you go.


i think when you unplug the relay or plug connector causing the problem, you should be able to see which one it is
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Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years

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Citroening
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Re: Fuel issue

Post by Citroening » 11 Mar 2014, 15:01

A few months back I had the same headache on a CX and was trying to find out the cause.

Symptoms were the same, it would briefly start, idle but then die.

Car was a 25 GTi Turbo, so a similar'ish set-up to yours...

You name it, I changed it...fuel pump, coils, fuel pump relay, fuel filters, AEi Ignition Computer.

As per usual it was the last thing to try - changed the Jectronic ECU in the passengers footwell and away it went...

Easy way to check fuel - crack off the fuel banjo nut on the injector rail and crank it over - mind your face though...
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Franklin

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Re: Fuel issue

Post by anucat » 11 Mar 2014, 15:40

Citroening i'm assuming the Jectronic ECU is not otherwise referred to as the Big Blue is it? If not where is Big Blue located?


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Citroening
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Re: Fuel issue

Post by Citroening » 11 Mar 2014, 15:50

Indeed two different things.

The Jectronic ECU is about 20cm square in size that sits behind a plate in the passengers footwell.

Pull down the carpet and from memory there's a couple of 10mm or 11mm nuts which secure it to the plate.

The "big blue" is your fuel injection relay, and they can indeed play up.

Off hand I can't 100% remember if it's below the N/S or O/S headlight on your model however it might also be black in colour.

You can bridge the relay, though, to permanently engage the fuel pump using some wire between two of the terminals.

The fuel pump shouldn't be audible all of the time with ignition, just as the key it moved to the crank position it should engage.

Best bet for fuel check is crank the banjo nut off, though. Takes less than a minute and will give you an answer as to if you've got fuel coming up.

You've also got an electrical connector underneath the driver's carpet which can suffer from corrosion and/or being disturbed by your feet over time.

This runs from the pump to the relay, I believe...

But if you've got fuel coming through at a good pressure (if really should fly out...) then you can rule that side of things out...
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Franklin

citronut
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Re: Fuel issue

Post by citronut » 12 Mar 2014, 10:10

Citroening wrote:Best bet for fuel check is crank the banjo nut off, though. Takes less than a minute and will give you an answer as to if you've got fuel coming up.


and try to refrain from striking a match whilst doing the above :twisted: [-X #-o :-D :rofl2:
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Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years

anucat
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Re: Fuel issue

Post by anucat » 12 Mar 2014, 12:52

Ok I thought I'd start with the easy option and check the air supply plenum first. As I expected, no splits. No splits....but further down where it joins the fan(?) the whole thing had disconnected. Reconnected , jubilee clip tightened and hey presto it started.

While there though I decided to clean as many electrical connections as I could find in an attempt to cure the unsteady idle the cars had since I bought it, on the assumption it's an EFI/electrical issue. That all done but no change.

The symptoms are unsteady idle (needle wavering 100rpm either side of 10,000 RPM) and white smoke from exhaust - quite a bit on start up. It has a kind of "phut phut" miss on idle, but drives well.

I'm not losing coolant and the oil is not watery so I'm ruling out head gasket issues. I'm not losing oil either.

I cleaned the connections to the coils - there are two coils with two outlet cables on each.again, made no difference.

Incidentally I never did find Big Blue behind the headlights. No idea where it is.


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citronut
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Re: Fuel issue

Post by citronut » 12 Mar 2014, 20:08

anucat wrote:
The symptoms are unsteady idle (needle wavering 100rpm either side of 10,000 RPM) and white smoke from exhaust - quite a bit on start up. It has a kind of "phut phut" miss on idle, but drives well.



is it possible it is running way to rich?????
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Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
purple and lilac metalic 2CV(VIOLET)registered to her in doors
1972 DS special been layed up aprox 31 years

anucat
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Joined: 10 Sep 2013, 11:18
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Re: Fuel issue

Post by anucat » 12 Mar 2014, 22:30

Yes but why?


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