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Series 3 Petrol Starting Issue


cmarsh02

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Hi again,

Wonder if anyone might be able to suggest any solutions to a starting problem I'm having with my S3 2.25 petrol, with a Weber 34 ICH carb'?

She died on me at at junction last weekend and I couldn't get her going and I wondered if the fuel had got too low in the tank, so I put 20litres of fresh petrol  in and she started eventually.  Got her home and when investigating what the issue might be I found when priming the fuel pump manually there was no resistance and only bubbles made their way to the (rather empty) inline fuel filter.  Also found the pump had a slight movement where it's fixed to the side of the engine.

So I replaced the fuel pump, along with a new gasket and nuts where it fixes to the engine and replaced the inline fuel filter too (also checked the lines and fixings).  When I manually primed the pump the inline fuel filter filled, which was an improvement and there was more resistance this time too.  She fired up after a few key turns and the fuel bowl on the pump filled up.  She ran perfectly for 15 minutes at both idle and high revs.  I turned her off and then she wouldn't re-start.

What I've noticed is that when you hold the ignition key in the starting position 4 she fires & runs, but as soon as you release the key and it goes into the usual running position of 3, she dies.

Can anyone suggest why this might happen, and what the 'fix' might be?

Many thanks in advance,

Chris

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The firing-when-being-cranked but cutting-out-when-you-relase-the-key makes me suspect a problem with the starter-solenoid/ballast-resistor.

When it's being cranked the ballast-resistor is bypassed so full +12V (or whatever the battery can muster) is applied to the LT side of the coil.

Release the key and the ballast-resistor is now in-circuit, so the coil gets a reduced voltage for normal running.

If the key-switch or the solenoid or the ballast-resistor connections are poor, you can get the symptoms you see.

[I once had an original 1960s Mini - it would fire first-time every time when the engine was cranked but misfired like an epileptic bullfrog on heat and/or cut out immediately I released the key. Turns out the wire from the ballast to the coil had broken inside the plastic cover on the Lucar connector where it plugged on to the coil. With the engine stationary/being cranked the broken ends made contact but as soon as the engine was running the vibration - it's a BL A-series remember - parted the break - which made the engine misfire and vibrate, so re-making the contact for a couple of firings so off it went again ... for a second...]

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39 minutes ago, steve b said:

The 2 1/4 is a 12v coil - only V8 LR products have the 9v coil and ballast wire as far as know .

cheers

Steve b

Trouble is we never know what's been fitted to a vehicle without clapping eyes on it.  Ballast resistor was my 1st thought, but checking the diagrams they weren't fitted as standard to Series vehicles.

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Just an update on my query - whilst following up on the suggestions and checking things I found in manuals etc, I also connected a wire from the battery +VE to the coil +VE and she started 1st time, but when I removed that wire she wouldn't.  So having investigated the cable connecting to the coil +VE, it would seem that there was an intermittent contact issue (at the ignition barrel/switch end).

So I cleaned up the spade and made sure the female connector was securely seated and now it seems to be starting every time.

I'm now wondering if it's worth carrying a wire with a crocodile clip on one end and a female spade connector at the other, so that it were to happen again, at least you could get yourself home before having to take the dash to bits....:o

Thanks again for your help - much appreciated!

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52 minutes ago, cmarsh02 said:

 

I'm now wondering if it's worth carrying a wire with a crocodile clip on one end and a female spade connector at the other, so that it were to happen again, at least you could get yourself home before having to take the dash to bits....:o

..doesn't everyone do this ? :P 

Nice fault finding work , a logical and simple way to test it .

Good to hear it is sorted out

cheers

Steve b  

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Several wires and several terminations in my toolkit! Plus my current LR product has a wire permanently connected to the starter solenoid which is taped up within easy reach of the battery... :D (but that was the work of a previous owner..)

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