Fordmods Logo

3 coil packs, 2 sets of leads, still mis-firing (dual fuel) 

 

Page 1 of 4 [ 52 posts ] Go to page 1, 2, 3, 4  Next

 
 Post subject: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Fri Jan 15, 2010 12:34 pm 
Stock as a Rock
Offline
User avatar

Age: 27

Posts: 131

Joined: 29th Jun 2008

Gallery: 3 images

Ride: AUII Futura

Location: melbourne
VIC, Australia

heres the story, had an engine change about 2000km's ago... mix and matched parts from the old one on the new block.. and used my old leads and coil-pack, but new plugs.
car was running fine initially, but after a few hundred k's of the run-in, it started mis-firing. did a changeover for another coilpack and it got worse. changed it for yet another coilpack and leads (the standard motorcraft leads), and it stopped mis-firing, till last night.
completely randomly driving home, nothing out of the ordinary, pull up at the lights only to have it backfire hard when i accelerated (on gas). the car is pretty much un-driveable on gas as it just keeps backfiring when it misses. on petrol it doesnt backfire, but it is running a little rough under load.

my question, is there a reason why its frying coilpacks? could they be getting too much voltage? and is there a point in buying an aftermarket one and seeing if it lasts any longer?

any help appreciated,
adam
Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Fri Jan 15, 2010 6:03 pm 
Getting Side Ways
Offline
User avatar

Age: 45

Posts: 1953

Joined: 1st Feb 2006

Gallery: 25 images

Ride: BA on gas. EL on gas. XF on gas.

Location: Greenacres/Adelaide
SA, Australia

You may be getting spark leakage at the plug end of the lead.
I had this and fitted another set of plugs and have no problems now.

You may also want to try this....Dielectric grease.
ford-lpg-hydrogen-hho-cng-conversions-f44/ba-injected-gas-spark-plugs-t86198.html
blownba wrote:
The other thing you MUST use on any car with coil on plug and plugs down in the cylinder head is Dielectric grease. This grease will act as a electrical insulator creating a insulation around the plug to rubber boot that would require more than 80,000 Volts for the spark to even think of getting through. This will eliminate the chance of spark leakage that is so common on the BA's which leads directly to incomplete combustion, or as we know it, BACKFIRE!
Smear each coil boot with dielectric grease on the inside of the ends. So where the coil boot goes onto the plug and pull the boot off and smear some where the boot meets the coil too as this is the most common place for spark leakage to occur.
Dielectric grease will make a BA plug change complete and guarantee you the best chance at perfect ignition which will result in NO backfires.
I do this to all the BA's I put plugs in and I am yet to have a report of a single backfire since I have been using Bosch Double platinum's and dielectric grease.

 

_________________

Member Number 8804
Image

Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Fri Jan 15, 2010 6:24 pm 
Moderator
Offline

Posts: 14513

Joined: 7th Nov 2004

Ride: ford falcon au3 xr8

Location: a shit suburb in sydney
NSW, Australia

you changed the leads! did you use new leads? or second hand leads?
Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Fri Jan 15, 2010 7:53 pm 
Getting Side Ways
Offline

Posts: 6449

Joined: 11th Nov 2004

if it's fine on petrol and only miss fires on gas then your gas system needs to be tuned.
what spark plug gap are you using?

 

_________________

PERMANENTLY BANNED

Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Fri Jan 15, 2010 9:30 pm 
Stock as a Rock
Offline
User avatar

Age: 27

Posts: 131

Joined: 29th Jun 2008

Gallery: 3 images

Ride: AUII Futura

Location: melbourne
VIC, Australia

second hand leads, but working on another car, and all with good resistances. it was mainly to diagnose if leads were an issue.

and it misses on both gas and petrol but with petrol the car is at least runnable. gas just backfires every time i accelerate, the plugs were brand new NGK 1.1mm (dual fuel gap)

i'll try that di-electric grease tomorow and see how that goes.. fingers crossed, i'm getting sick of this.
Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Fri Jan 15, 2010 9:52 pm 
Getting Side Ways
Offline
User avatar

Posts: 807

Joined: 28th Oct 2008

Location: melburn
VIC, Australia

1.1mm is too large a gap for gas...
should be .8mm
re gap your plugs before trying anything else as this is most likely the problem

 

_________________

XG Panelvan
mild engine, EL ECU & J3, HI6 & MSD coil

in the shed - .595" lift cam, GT4202, forged AU engine, ems 4424 ecu, glide & 5500 stall - next-bellhousing

XH ute daily - DOHC BA XR6 engine, T5, AU3 ECU, J3 chip, wideband & logger, ported BBM, 3" intake

Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Fri Jan 15, 2010 10:02 pm 
Stock as a Rock
Offline
User avatar

Age: 27

Posts: 131

Joined: 29th Jun 2008

Gallery: 3 images

Ride: AUII Futura

Location: melbourne
VIC, Australia

misk_one wrote:
1.1mm is too large a gap for gas...
should be .8mm
re gap your plugs before trying anything else as this is most likely the problem


i thought 1.1mm was the correct gap for dual fuel au2?
i'm still puzzled as to how it all worked perfectly without a single backfire for ~300km's, and then decided to happen randomly.
Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Fri Jan 15, 2010 10:06 pm 
Getting Side Ways
Offline
User avatar

Posts: 807

Joined: 28th Oct 2008

Location: melburn
VIC, Australia

sorry i had a boosted setup in my mind for some reason :)
gap them to 1mm and see how you go, LPG should always have a slightly tighter gap.

either way, its something you can try thats free and is known to help with an engine that has a miss

 

_________________

XG Panelvan
mild engine, EL ECU & J3, HI6 & MSD coil

in the shed - .595" lift cam, GT4202, forged AU engine, ems 4424 ecu, glide & 5500 stall - next-bellhousing

XH ute daily - DOHC BA XR6 engine, T5, AU3 ECU, J3 chip, wideband & logger, ported BBM, 3" intake

Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Sat Jan 16, 2010 7:26 pm 
Getting Side Ways
Offline
User avatar

Age: 30

Posts: 824

Joined: 10th May 2007

Ride: Xr6 Turbo

Location: Melbourne
VIC, Australia

test your inlet manifold for any leaks :)

 

_________________


Previous cars


1995 ef futura - nothing special
2003 xr6 turbo 5 -speed 307rwkw

Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Sat Jan 16, 2010 7:41 pm 
Getting Side Ways
Offline

Posts: 6449

Joined: 11th Nov 2004

adam_k wrote:
misk_one wrote:
1.1mm is too large a gap for gas...
should be .8mm
re gap your plugs before trying anything else as this is most likely the problem


i thought 1.1mm was the correct gap for dual fuel au2?
i'm still puzzled as to how it all worked perfectly without a single backfire for ~300km's, and then decided to happen randomly.



is the engine earthed to the body properly. about 6 years dad and I rebuilt the engine in his EB, we both over looked the earth strap, it did pretty much what you are suffering from. Your earth may have come loose

 

_________________

PERMANENTLY BANNED

Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Sun Jan 17, 2010 8:54 pm 
Stock as a Rock
Offline
User avatar

Age: 27

Posts: 131

Joined: 29th Jun 2008

Gallery: 3 images

Ride: AUII Futura

Location: melbourne
VIC, Australia

tickford_6 wrote:
adam_k wrote:
misk_one wrote:
1.1mm is too large a gap for gas...
should be .8mm
re gap your plugs before trying anything else as this is most likely the problem


i thought 1.1mm was the correct gap for dual fuel au2?
i'm still puzzled as to how it all worked perfectly without a single backfire for ~300km's, and then decided to happen randomly.



is the engine earthed to the body properly. about 6 years dad and I rebuilt the engine in his EB, we both over looked the earth strap, it did pretty much what you are suffering from. Your earth may have come loose


i had a look at the earth today, i'm thinking its the earth because i did spray the block black before it got dropped in. i scraped off all i could off the metal but i think there was paint under the braket that the ground was nut was attached to and also in the hole.
Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Tue Jan 19, 2010 5:35 pm 
Stock as a Rock
Offline
User avatar

Age: 27

Posts: 131

Joined: 29th Jun 2008

Gallery: 3 images

Ride: AUII Futura

Location: melbourne
VIC, Australia

no luck on the earths in the end.
what other sensors could be causing it to do this?
Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Tue Jan 19, 2010 7:28 pm 
Getting Side Ways
Offline
User avatar

Posts: 1140

Joined: 27th Feb 2005

Ride: Supercharged EF Fairmont

Location: T.I. Performance HQ
VIC, Australia

Is the ignition timing retarded?

Are the gas mixtures rich enough? Is the balance line hooked up correctly?

Jason
Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Tue Jan 19, 2010 7:31 pm 
Getting Side Ways
Offline
User avatar

Posts: 807

Joined: 28th Oct 2008

Location: melburn
VIC, Australia

i would still try regapping your plugs before looking at other sensors

 

_________________

XG Panelvan
mild engine, EL ECU & J3, HI6 & MSD coil

in the shed - .595" lift cam, GT4202, forged AU engine, ems 4424 ecu, glide & 5500 stall - next-bellhousing

XH ute daily - DOHC BA XR6 engine, T5, AU3 ECU, J3 chip, wideband & logger, ported BBM, 3" intake

Top
 Profile  
 
 
 Post subject: Re: 3 coil packs, 2 sets of leads, still mis-firing (dual fuel)
Posted: Tue Jan 19, 2010 8:10 pm 
Getting Side Ways
Offline
User avatar

Age: 45

Posts: 1953

Joined: 1st Feb 2006

Gallery: 25 images

Ride: BA on gas. EL on gas. XF on gas.

Location: Greenacres/Adelaide
SA, Australia

Do this at night.
Warm the car up.
Hand brake on (chock wheels if needed).
Put it in drive and watch for spark leak at the plugs and along the leads.

 

_________________

Member Number 8804
Image

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 4  [ 52 posts ]  Go to page 1, 2, 3, 4  Next

Who is online

Users browsing this forum: No registered users and 22 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Fri Dec 15, 2017 2:11 pm All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names