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RV8 megajolt problems again.
Irony - 28/3/15 at 04:29 PM

Here we go again. Struggled to get my RV8 megajolted webber 500 goingafter winter. Stupidly left it unstarted throughout. Ended up sending the ccarb away for servicing. Webber specialist said it was gummed up inside from bad petrol. Upon restarting it runs rubbish. Backfiring and allsorts. Doubled check the ignition lead order and i think there okay. Hoqever 4 exhaust headers are cold and 4 hot. All four cold ones run back to the samé ignition coil. Double checked the connections and thereokay. Is it possible for a coil to just give up?

coozer - 28/3/15 at 04:32 PM

It is possible, have you tried swapping the coils over to see if the cold ones go to the other side?

Irony - 28/3/15 at 05:31 PM

quote:
Originally posted by coozer
It is possible, have you tried swapping the coils over to see if the cold ones go to the other side?


No not yet. I got cheesed off and came in.

rusty nuts - 28/3/15 at 06:30 PM

quote:
Originally posted by coozer
It is possible, have you tried swapping the coils over to see if the cold ones go to the other side?


Good suggestion

Irony - 1/4/15 at 08:08 PM

New coil turned up today and its still the same. Still cold headers on the one coil. Checked over the wiring and no joy. Then my starter motor packed up. My dad suggested hitting with a hammer. The car started again but still running on four cylinders only.

scudderfish - 1/4/15 at 08:20 PM

Which 4 are hot and which are cold? That will tell you if the problem is isolated to one pack or not. Physically swap the coil packs over. If you get the same result then there is probably a problem between the EDIS and the pack; if you get the cold ones now hot, you have a duff coil pack. List here which cylinder is connected to which post on which pack, and which cylinders are running cold.

Regards,
Dave

P.S. My money is on a broken earth to one coil pack

Irony - 2/4/15 at 07:59 AM

I bought a new Coil pack as I was pretty certain it was that. I plugged the new coil pack in and ended up with the exact same result.

I have chased all the cold headers back to the same coil via the ignition cables. I can't remember the exact cylinders now as I am at work but I am pretty confident the ignition cables are wired in correctly and the VR sensor cables are the correct way round.

It runs the same with the megavolt plugged in or not.

Being as I had the same result after replacing the dubious coil it surely points to an issue between the coll and the Edis. I am loathed to throw more money at it and buy a new Edis8 module. I shall double check the wiring tonight. Those coil correctors are not the cheapest either! It's got to be a wiring issue or a duff edis8 surely?

richardm6994 - 2/4/15 at 08:43 AM

check the usual stuff.....coil plug connections, EDIS plug connections etc.....

if you still get nowhere, I've got a spare edis 8 I can post to you which will confirm / eliminate the EDIS as being the problem.........I had troubles early doors and bought another edis thinking it would solve a problem I had but turned out not to be an edis fault in the first place hence I now have a spare!

the only other thing I can think of but from what you say it doesn't sound like this is the cause but I'll mention it anyway......has the megajolt software reverted back to the 4 cylinde setting that it comes factory set at?

Irony - 2/4/15 at 09:27 AM

quote:
Originally posted by richardm6994
check the usual stuff.....coil plug connections, EDIS plug connections etc.....

if you still get nowhere, I've got a spare edis 8 I can post to you which will confirm / eliminate the EDIS as being the problem.........I had troubles early doors and bought another edis thinking it would solve a problem I had but turned out not to be an edis fault in the first place hence I now have a spare!

the only other thing I can think of but from what you say it doesn't sound like this is the cause but I'll mention it anyway......has the megajolt software reverted back to the 4 cylinde setting that it comes factory set at?


I have read through your post on the Rhocar forum about your early problem. Actually saw your car at Donnington last year or the year before but you were somewhere else. What was the problem with it in the end?

I have printed out your wiring diagram and I will check the earths and the various wires etc. Thanks for the offer of the edis8 - hopefully I won't need it. I unplugged the Megajolt and it runs the same so I doubt it's that.

richardm6994 - 2/4/15 at 10:22 AM

my problem was intermittent so really hard to pin down at the time.....I tried everything....vr sensors, edis, coil packs, leads, megajolt, new wirig......you get the picture......I tried changing the lot and couldnt pin down the fault....(basically the engine would keep missing / dying every now and then).

the problem was solved when we discovered a wirig error with the autosportlabs diagram when comparing it to other edis8/megajolt diagrams found on the Internet.....(I've copied and pasted this bit from my Facebook page)....

I discovered a few years ago an ERROR on the autosportlabs wiring diagrams......they show pin 7 connected to earth and shields.....DO NOT DO THIS....connect to shields only. This error causes an earth loop in the shield cable and reduces / eliminates the shield effect can result in dodgy PIP / SAW signals.
For the V8's out there, the autosportlabs wiring diagram also shows the edis plug the wrong way around (ford changed the plug orientation on the edis 8).
I've done my own diagrams that I work to and I know work well so please feel free to use and share these.





I know of a lot of people with edis4 who have worked up as per the autosportlabs diagram and don't have any problems.....but for me, when I rewired it as per the diagram I've produce, the problem vanished for good......and just t be sure.....when I reconnected pin 7 the problem reappeared straight away.

https://m.facebook.com/story.php?story_fbid=432951576852910&id=410501685764566

[Edited on 2/4/15 by richardm6994]