Sporty
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| posted on 29/6/15 at 10:48 AM |
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Zetec cutting out
Wondered if the collective had any pointers as to where to start with the above issue.
It is a Zetec with ZX9r carbs and a megajolt.
Engine runs fine and then loses Power and will not rev seems to do it after about 10 mins of driving and possibly after ive just gone round a corner
(But that might be a red herring)
Pull over switch off and start again and works fine.
My first thoughts are
I am not running a huge amount of fuel is that I am creating an airlock in the fuel line as the fuel sloshes around.
Is the megajolt failing but if this was the case I would have thought it would still rev just with less power using the Edis.
Any thoughts of where to start investigations appreciated.
Thanks
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coozer
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| posted on 29/6/15 at 10:54 AM |
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Sounds like fuel, what setup you using from the tank to the carbs?
1972 V8 Jago
1980 Z750
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Sporty
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| posted on 29/6/15 at 10:57 AM |
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Its a Facet pump but the car has been stood for a couple of years and the tank drained maybe the fuel filter would be a good place to start.
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ravingfool
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| posted on 29/6/15 at 11:33 AM |
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tank vent blocked leaving you with negative pressure in the tank and pump struggling to supply fuel to carbs?
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coozer
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| posted on 29/6/15 at 11:39 AM |
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What Facet is it? May be a bit unsuitable for bike carbs. Can I suggest changing it to a bike pump?
1972 V8 Jago
1980 Z750
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r1_pete
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| posted on 29/6/15 at 11:52 AM |
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quote:
Originally posted by ravingfool
tank vent blocked leaving you with negative pressure in the tank and pump struggling to supply fuel to carbs?
I'd agree this is probably the first thing to check, can you drive with the filler cap off or loose, to create a vent and see if it still
happens??
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Sporty
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| posted on 29/6/15 at 01:02 PM |
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All sounds very feasible thanks, a bit relieved that the general view is that I need to fault find the fuelling system rather than the megajolt.
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Ugg10
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| posted on 29/6/15 at 01:22 PM |
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As already said, sounds like a fuel problem, The facet pump (posi-flow) on my Zetec Bike carb setup needed a fuel regulator set to approx. 2psi (less
than the usual weber carb 4 psi). Worth checking this out as well as it may be flooding with the higher pressure.
---------------------------------------------------------------
1968 Ford Anglia 105e, 1.7 Zetec SE, Mk2 Escort Workd Cup front end, 5 link rear
Build Blog - http://Anglia1968.weebly.com
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Jenko
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| posted on 29/6/15 at 02:10 PM |
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Don't the carbs have a float which acts as a buffer for the fuel supply...With injectors this is an issue, with carbs, it's not usually as
pronounced.
So, I'll go against the general consensus and say electrics. However, before I put my head on the block....you say after 10 mins....Is that 10
mins from cold or any time it's restarted. When you restart, does it fire up ok or take a time to fire up. do you need to turn the engine off to
get it to work again?, or does it recover.
Back to megajolt...assuming you are using edis 4, they have limp home, which goes to a fixed 10 degree advance, with this activated you would struggle
to rev the engine. I would try to see if the advance is advancing when your car fails (Carry a timing light with you). Common cause for this is the VR
sensor....worth checking it's not hitting the trigger wheel.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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Sporty
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| posted on 29/6/15 at 03:01 PM |
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Thanks Jenko always appreciate someone going against the flow.
It's not really happened often enough to start drawing too many conclusions just had it back on the road a week.
You may be right about the bowls providing a buffer, but thinking about it, it has happened after harsh acceleration coming out of a bend and
overtaking so that would seem to add weight to fuelling debate.
When it comes to a timing light, it obviously only happens in the worse places never just before a layby where you get chance to have a good look,
usually just pleased it starts again.
Sods law says it will be something completely unrelated, but makes sense to look at the obvious first.
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Jenko
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| posted on 29/6/15 at 03:06 PM |
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I guess the only thing that's putting me off going with the 'fuel' issue, is the fact that it seems to reset itself when you turn
the engine off and on. Why would this be. If it was fuel starvation, then when you come off the throttle and drive slowly you would expect it to
recover.
If said issue is happening after full throttle runs then that does swing more towards fuel......
I reserve the right to change my mind pending a load more info on the conditions around the failure :-)
Edit to post... if it's related to full throttle runs, can you check you megajolt file to ensure the tps has the correct calibration, and you
not getting some spurious ignition advance number when foot is mashed to the floor.
[Edited on 29/6/15 by Jenko]
[Edited on 29/6/15 by Jenko]
[Edited on 29/6/15 by Jenko]
MY BLOG - http://westfieldv8.blogspot.co.uk/
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Sporty
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| posted on 29/6/15 at 03:10 PM |
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I will report back
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rusty nuts
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| posted on 29/6/15 at 04:31 PM |
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Check the pumps fuel delivery rate , I've had a Facet pump struggle to deliver fuel due to the screw in fuel filter getting blocked, I now use a
disposable filter as a prefilter and have had no problems since
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Dusty
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| posted on 29/6/15 at 11:13 PM |
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Another vote for the facet screw-in fuel filter. Spawn of the devil. Took me months to work it out when it kept happening to mine. Seems to be able to
work OK for miles and then block. Coming to a halt on motorways typically but by the time I had pulled up the engine would restart and maybe run for
another 300 miles before coasting to a halt again. Those filters should be banned.
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Sporty
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| posted on 6/7/15 at 11:56 AM |
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Update on the above problem, and hopefully the solution.
Tested the system for the flow rate to the carbs, pumped a litre in approximately a minute, which seems spot on for a pump that supposed to deliver
55l/hr.
Someone else suggested that as it has been stood then the carbs might need a clean, so a good spray with carb cleaner and we seem to have solved the
problem, car is running generally a lot better and no cutting out.
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rusty nuts
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| posted on 10/7/15 at 01:05 PM |
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I suggest you read the post before yours!
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