misfire?

General Topics for configuring, operating and tuning the Megajolt. Also see the <a href="http://www.autosportlabs.net/MJLJ_V4_Operation_Guide">Operation Guide</a>

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spud15
Posts: 5
Joined: Sat Feb 11, 2012 9:15 am

misfire?

Post by spud15 »

I have the megajolt lite jnr on a v6 - im getting intermittent popping on 1 x exhaust ( dual system) - have changed the leads on that side but no joy - its the 1st time ive started it on the mega jolt - does anyone know what it might be?

brentp
Site Admin
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Post by brentp »

Is it an intermittent hesitation at a certain RPM? often this is due to a trigger wheel -> sensor alignment issue, or sensor vibration due to a flexing mounting bracket.

Also, is this an emerging problem after some time of successful running, or is it a new system you're working on running for the first time?
Brent Picasso
CEO and Founder, Autosport Labs
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spud15
Posts: 5
Joined: Sat Feb 11, 2012 9:15 am

Post by spud15 »

Hi brent - thanks for the answer - i put the toothed wheel / harmonic balancer on the lathe - turned it down - now 2 thou out of true over all - so nice - aligned the sensor nicely - under a ml clearance - works well at idle now. (it is a new application - on an essex 3ltr v6 - ford capri). It does pop a lot at revs but idles ok now. Im struggling to get the computer to talk to the mega jolt but still trying a few things ....

spud15
Posts: 5
Joined: Sat Feb 11, 2012 9:15 am

Post by spud15 »

Hi Brent - have it running - brought a new computer with the correct port - but have a mis fire at idle - if i take the lead of no.1 - it stops - however there is spark to the plug - it also misfires at high revs ....

brentp
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Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

A couple of things you can check:

- Sensor bracket flexing / vibrating at certain RPMs. if the sensor is vibrating it can alter the signal to the EDIS module, causing a mis-fire. Making the bracket more rigid may help.

- you might want to check for lean conditions on your cylinders- this could cause the popping / misfiring.
Brent Picasso
CEO and Founder, Autosport Labs
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spud15
Posts: 5
Joined: Sat Feb 11, 2012 9:15 am

Post by spud15 »

Thanks Brent - no the leads are okay - switched them around etc - no difference - i put a new coil pack in - no change - the sensor is mounted on an aluminium block (60 x 60 x 20 ml) welded to the timing cover. - verry stable. When i put the dizzy back on - the prob disappears so has to be the edis somewhere. Could it be the sensor? and why only on no.1

spud15
Posts: 5
Joined: Sat Feb 11, 2012 9:15 am

Post by spud15 »

Got it going okay - input signal now excellent, new coil pack, wiring etc but on the dyno - it will spontainiously retard around 20 degrees and go back to normal. The abnormality happens in an instant and returns with no explanation .. any thoughts?

brentp
Site Admin
Posts: 6282
Joined: Wed Jan 24, 2007 6:36 am

Post by brentp »

Does it still happen with the Megajolt disconnected (running only on EDIS in 'limp home' mode)?

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