Son's 'student car' with coat hanger aerial accessory etc - starts OKish, runs OKish at high revs but on depressing accelerator get 'die off' (partic at lower revs and going up incline)which slowly picks up again and then seems to run OK. Checked Ignition side of things (but no expert) - plugs new and gapped OK, batt. OK, coil gives correct resistances, diz cap looks OK (I think), leads seem OK too. Was serviced recently with new fuel filter, air filter, plugs, valve adjustment, oil change. Seemed better for a while now back to square 1. Son says better in the wet. Redex in tank and direct into carb. - no difference.
I presume it's a fuel side problem? Likely culprits?
Cheers for any help
Alban
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Had similar problem on my old Sunny of the same vintage - improved dramatically by narrowing the gap on the plugs (IIRC it should be 0.9mm, try using 0.7mm), and replacing the cap and rotor arm. Using NGK spark plugs it ran MUCH better than with anything else. Could be the carb - sticky accelerator pump? Those Nikki carbs are extremely complex and I couldn't find anyone brave enough to strip mine without making me agree that if they damaged a diaphagm or lost a spring that I wouldn't hold them responsible!
Incidentally, mine ran worse in the wet - in fact sometimes the engine would die completely, backfire, then carry on as normal! This was particularly unpleasant as it caused the car to leap around as if I'd forgotten how to use the clutch!
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Forgot to add - check the ignition timing because the timing chain might've stretched and knocked it out.
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Thanks for that- some pointers at least!
Alban
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Noticed, when testing, that the spark from plug leads to ground is yellow/blue and that when testing 1, 2 & 4 leads, lead 3 arcs to the engine body! Surely this is not right? Does it indicate a fault in ignition system?
Cheers
alban
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No fault in ignition system;fault in lead!!
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Or are you saying you get a spark on #3 at the same time as the others spark? in which case sounds like distributor cap fault
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The arcing from lead 3 to engine block only occurs when I detach any of the other leads and look at its spark from lead to ground. As 1, 2 or 4 was detached and sparking, another spark appears from lead 3 whilst it's still fixed to the plug ie sideways out of the plug cap to the metal of the engine. This does not occur when all 4 leads are in place. I'm not sure that it's actually at exactly the same moment the detached lead sparks tho'.
Should the spark to ground from any of the leads look completely blue if everything is OK? Will the distance from ground it has to jump (which I didn't keep consistent-see PS) affect its appearance?
Alban
PS. I always got shocked by any lead whenever I handled them by the rubber cap! Is that normal? Made it a bit difficult to control, jigging about and yelping!
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PS. I always got shocked by any lead whenever I handled them by the rubber cap! Is that normal? Made it a bit difficult to control jigging about and yelping!
Use properly insulated pliers to pull the leads off, or do so when the engine's not running. How old are the leads? Have you checked the contacts on the inside of the dist cap? And the rotor arm of course?
If the spark's not as blue from one particular lead, that might imply that the lead's knackered - resisting current, resulting in a lower voltage at the sparking end. IMO, replace lead 3 and see if the arcing continues.
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Was the leads - new set from ebay and runs fine now. Thanks to all.
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