390se timing settings and Marks on front pulley

390se timing settings and Marks on front pulley

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Discussion

Rockettvr

Original Poster:

1,850 posts

153 months

Saturday 11th June 2022
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Hi all
Had some ignition issues with my sons 390Se
(Due to poor spark)
I replaced the ignition amp on the side of the dizzy which meant moving the dizzy to be able to get to the screws - dizzy then returned to original position.
Car is now sparking well but starts to play up once revs get up to about 4500/5000 rpm (loss of power popping and banging)
Re timed the ignition- there was an existing mark at 10deg btdc so timed assuming this was correct - It was a gnats out from my approximate “that’s where it was “ when returning dizzy to original position
No change - car just loses power pops bangs at 4500rpm
I’m aware that the timing marks maybe incorrect and thought that the existing mark maybe tdc and retimed to that
Marginal improvement but still issues reving beyond 4500
So thought I’d do the “piece of wire down no1 plug hole “ to confirm tdc and that would seem to be at about 20deg btdc on the pulley marks
That seems an awful long way out and it means that I’d have to move the dizzy an awful lot from what was it’s original position which doesn’t seem at all right
Any suggestions?? I’m struggling to understand what’s happened
Dizzy was never moved out just pinch bolt slackened and dizzy rotated
Could someone please confirm what the reading should be also please (10 deg at idle 28deg at 3500 I think ? )
Thanks


nwarner

612 posts

270 months

Saturday 11th June 2022
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I set my 390SE to 8 degrees just above the blue line shown on my pulley. I come across other people who marks are way out but it's strange if all you've done is twisted the dizzy round and then back. Have you tried connecting the old ignition module up to see if it makes a difference? I can't see how it would though but maybe worth a try. Also you said you replaced the plug leads, they are still in the correct order smile

Nige



Edited by nwarner on Saturday 11th June 20:01

wild rover

448 posts

191 months

Saturday 11th June 2022
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Have you checked that the advance retard operates.

adam quantrill

11,584 posts

252 months

Thursday 16th June 2022
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Vacuum line looking OK onto dizzy too?

On my 400SX the timing marks were way off, I dialed in TDC from the piston itself. Always worth checking the timing before disturbing anything, then you can put it back after.