Fuel issues with SE5a

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ScimiTom
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Fuel issues with SE5a

Post by ScimiTom » Tue Jun 26, 2018 9:29 pm

I know this is the kind of topic which crops up frequently, but I'm hoping someone can help diagnose the specific symptoms I'm getting with my 5a.

The last few times I've had the car out, it has run fine for the first 15-20 minutes, then started stuttering and juddering erratically before cutting out. After a little time and a lot of encouragement (choke out, tons of throttle and revs to stop it dying), it'll fire up again and get me back home. It doesn't appear to be overheating.

It now refuses to fire up at all. The engine will turn over, but no sooner does it fire up than it immediately dies again. There is enough petrol in the tank and the battery is fully charged. It has a Facet pump fitted by the tank. New Cohline fuel hoses and a Filter King were fitted a year ago (the previous glass filter before the carb is still in place) and it has covered many trouble-free miles since then.

I have one or two ideas of what's causing it, but would like to see what the experts out there say first. Thanks in anticipation.

Tom


Current: 'Boffin' (1971 SE5a)
Previous: 'Sunshine' (1980 SE6b)

Terry H
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Fuel issues with SE5a

Post by Terry H » Tue Jun 26, 2018 9:48 pm

Have you tried starting it with the fuel cap open. it could be the old vacuum in the tank stopping the flow of fuel.
Regards Terry H
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Fuel issues with SE5a

Post by rebel alliance » Tue Jun 26, 2018 9:49 pm

Sounds like the coil is getting power from the starter motor wire as you turn it over which could be why it stops as soon as you stop cranking...try a wire from the battery direct to the coil first



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Fuel issues with SE5a

Post by scimjim » Tue Jun 26, 2018 11:32 pm

I’d start with coil or ignition switch - prove/disprove by hotwiring.


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Fuel issues with SE5a

Post by rkclodhopper » Wed Jun 27, 2018 7:29 am

While someone else is cranking the engine squirt a small amount of fuel down the carb intake, after removing the air filter. If its got ignition it will run briefly on the fuel you administer. Be careful with the fuel and have a extinguisher at hand.

Richard



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Fuel issues with SE5a

Post by ScimiTom » Wed Jun 27, 2018 8:35 pm

Thanks for all the responses. Terry may be onto something as I tried with the fuel cap open and it did eventually start up. I was able to keep the engine idling for about 30-40 seconds, then the revs started to fluctuate again and it conked out. Does the fact that it did run, even for a short time, mean that I can discount the coil and ignition switch?


Current: 'Boffin' (1971 SE5a)
Previous: 'Sunshine' (1980 SE6b)

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scimjim
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Fuel issues with SE5a

Post by scimjim » Wed Jun 27, 2018 9:36 pm

Nope :(


Jim King

SECURE DRY STORAGE FOR YOUR SCIMITAR

Current: SE5 (8Ball), TI SS1 (snotty), 1600 SS1 (G97), 1600 SS1 (C686CCR), 2.5TD SE5a (diesel 5a), 6 x random other SS1s.
Previous: SE5, 3 x SE5a, 2 x SE6a, 3 x SE6b, GTC, 2.9i GTC, 3 x 1600 SS1, 1300 SS1, Mk1 Ti Sabre, Mk1.5 CVH Sabre
Chief mechanic for: 1400 K series SS1 (Megan3), 1400 CVH EFi SS1 (Grawpy), 1300 SS1 (Number One) & Sarah's coupe.
CURE THE FAULT - NOT THE SYMPTOMS

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Fuel issues with SE5a

Post by rebel alliance » Wed Jun 27, 2018 9:46 pm

Have you tried it with a hot wire yet ? If it makes no difference we can move forward....



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Fuel issues with SE5a

Post by willholderogri » Thu Jun 28, 2018 7:30 am

scimjim and rebel alliance has hit the nail on the head that's the first thing you need to do before dismantling the car if it still cuts out a while later try terry h fuel cap solution.
let us know how you get on


1962 mini, bedford CA , KR200. morris 1000, mini pickup.several escorts,ford grandad.ford cortina X2 ,astra, SE5A x 2 ,ford focus.

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Fuel issues with SE5a

Post by ScimiTom » Thu Jun 28, 2018 9:57 pm

Thanks for the tips, guys. Due to current circumstances I rarely get any opportunity to actually work on the car, so don't hold your breath! However, I will try your suggestions and report back in due course. :)


Current: 'Boffin' (1971 SE5a)
Previous: 'Sunshine' (1980 SE6b)

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Fuel issues with SE5a

Post by ScimiTom » Fri Jul 13, 2018 10:07 pm

Well, I've run one fuel hose straight from the Filter King to the carburettor (rather than running it via a surplus second filter as it was before), and replaced the perished O-rings on the idle jets, but sadly to no avail. Next will be to check everything in the carburettor. The issue still seems fuel-related rather than electrical.


Current: 'Boffin' (1971 SE5a)
Previous: 'Sunshine' (1980 SE6b)

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Nigel Clark
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Fuel issues with SE5a

Post by Nigel Clark » Fri Jul 13, 2018 10:32 pm

Fuel vaporization? Modern petrol seems to vapour lock now easily than good old 4 star.

My SE6A had suffered in the current warm weather. Sounds ridiculously simple, but I found wrapping kitchen foil around the hose from the fuel pump to carb helped. This hose is subject to plenty of heat as it passes over the LH rocker cover.

Nigel



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Fuel issues with SE5a

Post by rebel alliance » Fri Jul 13, 2018 10:45 pm

So hot wireing the coil made no difference ?



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Fuel issues with SE5a

Post by willholderogri » Sat Jul 14, 2018 7:48 am

As rebel said have you hotwired it yet ?


1962 mini, bedford CA , KR200. morris 1000, mini pickup.several escorts,ford grandad.ford cortina X2 ,astra, SE5A x 2 ,ford focus.

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Fuel issues with SE5a

Post by Pommy » Sun Jul 15, 2018 10:32 pm

Sounds very familiar to me, went right through the fuel carb system without sorting the problem, willholderogri suggested running a wire from the green terminal on the regulator to + on the coil, cured my stuttering cutting out, it also highlighted that my fuel pump, su type, was only getting an intermittent 10.5 volts, this was caused by more than one poor earths, I'm still chasing bad earths but the car runs now, hope this helps. Pommy


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1973 Se5a Auto

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