Jump to content

EDIS8 Running problem


dalbro69
 Share

Recommended Posts

Ive been running Megajolt on my 3.9l Disco1 with brill results for 6months now. However its developed a wierd fault. When you blip the throttle the engine stutters for a split second and this causes the LPG to backfire big time...destroyed 2 airboxes now . Other than the stutter the rev is smooth and the idle is smooth as normal. However if i remove the fuse for the MJ (v3) so i runs on EDIS8 at 10TDC it wont run..the engine shakes like hell and cannot be revved. Sometimes it wont even start on it even though it used to. Soon as i insert the MJ fuse the engine kicks back to being smooth with the blip problem...

Ive changed the sensor and bracket..no change..Ive fitted a second EDIS8 still the same.

Im lost..can anyone help

Thanks in advance

Link to comment
Share on other sites

If it worked for 6 months ok and developed a problem now that suggests that something physical is not working as it should

LPG is sensitive to spark quality hence check the spark is not tracking somewhere (run it at night and have a look under the bonnet). Also check the plugs to see that an insulator is not cracked

Edis has a very good quality high energy spark hence it likes to wonder if you have aged leads

Check plug gaps and plug tip cleanliness ( photos of plugs (numbered) are always helpful for comment

Next I would check the LPG system

What sort of LPG system are you running. Sequential injection or vapouriser ?

Check the mixture (wide band lambda sensors are always best). Narrowband you need to check for the rich to lean crossing of lambda 1 and the frequency.

Suggest if it worked fine before it's something physical changed its properties

What does it run like on petrol

Rob

Link to comment
Share on other sites

i will get all the info together and get back to you

what i can say is.. on petrol its smooth. The HT leads are from trigger wheels so cant imagine theyve degraded all of a sudden . Its running a single point lpg vapouriser. Its a very basic system so no sensors im afraid. As i say it was all of a sudden

Link to comment
Share on other sites

Echo the question for 'how does it run on petrol?'

I suggest the MJ/EDIS side of things may well be fine, and the issue is with a leaned-out LPG mixture, especially at idle, causing the backfires.

The fact that it runs very badly on LPG at 10 degrees is just cos it will run worse than if using the map, and if the mixture is an issue it is just highlighting this.

Link to comment
Share on other sites

Whilst I'm thinking about it.... Although not rover v8 related or edis, I've had an interesting issue with wasted spark ignition on a ford / Mazda sigma engine where it use to eat through coil packs like nobodies business (about 6 monthly). The problem started as an odd and occasional misfire under load normally when accelerating out of a junction or cold start.

Like always the problem was way worse when running on LPG (sequential injection)

The problem basically came from the location of the coil pack that is located on the end of the cylinder head on an aluminium mounting bracket. To which the coil pack was bolted. Also if you had a high rev'ing run it also seemed to be able to force the coil into early failure

Anyway swapped the engine out (another story) for a newer low mileage engine with a different engine prefix and it came with a plastic coil pack mount in exactly the same place, 2 years later and 40k same coil pack no issues at all.

New coil pack just sorted the problem there and then so it may be something worth considering if it runs rough on LPG and petrol but worse on petrol

If the problem is only apparent on gas then it will most likely be LPG specific related (gas tune, LPG injector seals knackered if sequential, regulator diaphragm (hole in it or gone brittle...)

Hopefully enough there for you to consider but basically bit more info needed as it could be many things but suggest don't change the map for the moment given that's been fine for six months

Rob

Link to comment
Share on other sites

If the problem is only apparent on gas then it will most likely be LPG specific related (gas tune, LPG injector seals knackered if sequential, regulator diaphragm (hole in it or gone brittle...)

As others have said, LPG is much more sensitive to a bad spark than petrol. It's perfectly possible to not notice it on petrol, but that you do feel it on LPG.

Link to comment
Share on other sites

Thank you for all your replies. I found the edis8 fault.....was my fault..removing a fuse to a coil n NOT megajolt...complete and utter idiot i am...you aught to know lol

The backfire was caused by a spark plug that had turned bad...the ceramic had cracked and under heavy load (blip of throttle) arc to the engine..cylinder then full of lpg...and megajolt has the redundant spark statem so........................BANG !!

Thanks again for the help, it was appreciated

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy