Big Daz
|
| posted on 18/11/07 at 11:50 AM |
|
|
Interesting Zetec spark issue
After months & months we have finally got our megasquirt fixed, Stuck it in the car yesterday and gave it a go.
Now the wierd bit.....
With 3 spark plugs in & one out earthed to block we get sparks fine & RPM on Megatune (car almost fires too). BUT as soon as we put 4th plug
in no RPM on Megatune and doesnt sound like sparking anymore.
Doesnt matter which plug is out - same results.
New Plugs, New coil, New VR & new leads.
Any Ideas what could be the issue?
Cheers
Daz
[Edited on 18/11/07 by Big Daz]
|
|
|
|
|
stevec
|
| posted on 18/11/07 at 11:59 AM |
|
|
Could it be something to do with the engine turning over faster with a plug out? perhaps getting a better crank trigger signal.
Steve.
|
|
|
Andy W
|
| posted on 18/11/07 at 12:12 PM |
|
|
Have a word with Tim Windmill, I'm sure he had similar problems. I think it turned out to be a fault in the megawotsit.
Andy
|
|
|
r1_pete
|
| posted on 18/11/07 at 12:45 PM |
|
|
have you got the three LT wires to the coil connected correctly? sounds like you're trying to fire all plugs at once which could happen if you
cross the common ground wire with one of the switched wires.
|
|
|
jambojeef
|
| posted on 18/11/07 at 01:05 PM |
|
|
Could it just be that it needs an earth strap connecting the head to the block?
|
|
|
Paul (Notts)
|
| posted on 18/11/07 at 01:14 PM |
|
|
I vote for the earth strap
Paul
|
|
|
jacko
|
| posted on 18/11/07 at 01:39 PM |
|
|
quote:
Originally posted by Andy W
Have a word with Tim Windmill, I'm sure he had similar problems. I think it turned out to be a fault in the megawotsit.
Andy
I go with Andy u2u Tim or Ray Ward he made tims mega thing
|
|
|
MkIndy7
|
| posted on 18/11/07 at 02:43 PM |
|
|
quote:
Originally posted by r1_pete
have you got the three LT wires to the coil connected correctly? sounds like you're trying to fire all plugs at once which could happen if you
cross the common ground wire with one of the switched wires.
Its normally a common Ignition live and switched earths.
|
|
|
MikeRJ
|
| posted on 19/11/07 at 02:46 PM |
|
|
If you leave all four plugs in the engine, and simply remove any HT lead and ground it, does this always make the MS work correctly?
Are you using the MS with an EDIS unit, or using built in coil drivers?
|
|
|
Big Daz
|
| posted on 19/11/07 at 09:45 PM |
|
|
quote:
Originally posted by MikeRJ
Are you using the MS with an EDIS unit, or using built in coil drivers?
No Edis, Dual coil drivers.
I can see the thinking re earth issue but I have never seen a car with an earth between the head & block !
|
|
|
paulf
|
| posted on 19/11/07 at 09:49 PM |
|
|
Is it turning over fast enough with all the plugs in to create a crank signal? is the battery fully charged and the starter in good condition?
Paul.
|
|
|
TangoMan
|
| posted on 19/11/07 at 11:33 PM |
|
|
quote:
Originally posted by Big Daz
quote:
Originally posted by MikeRJ
Are you using the MS with an EDIS unit, or using built in coil drivers?
No Edis, Dual coil drivers.
I can see the thinking re earth issue but I have never seen a car with an earth between the head & block !
Erm.... I think you have!! What about the 10 or so bolts that hold it down. I think you may find these make for the best earth you will get.
Summer's here!!!!
|
|
|
jambojeef
|
| posted on 20/11/07 at 10:26 PM |
|
|
I can easily see how arguments can start over internet postings since its so easy to misunderstand people without hearing their tone or being able to
get them to repeat what they mean in a different way so as to get the point across properly.
It seems in my rush to help out Ive made it sound as if I consider that the block and head need connecting together when of course both head and block
just need good earths.
Hope you get your problem sorted, let us know what it was in the end.
Geoff
|
|
|
.jpg)
