Misfire in 1256 engine

Tips and help requests for your cars electrics. Post your tips help other sort problems out.

Re: Misfire in 1256 engine

Postby vivapete3 » Thu Jun 01, 2017 2:02 am

droopsnoot wrote:I can't picture how it could specifically do damage, though I haven't seen the Accuspark system. Is it possible that what's happened is that, while removing and replacing the distributor a few times to fit, remove, re-fit and remove the Accuspark unit, something that was marginal is now worse?

I'm thinking in particular the low tension wire to the negative side of the coil - is it possible the wire was cracked, or coming away from a terminal at one end, and the movement has made it worse? Or any of the other wires, I guess.

Hi thanx for your advice re low tension wire suffering damage with distributor being opened up a few times, I checked the LT wire and the dizzy end of the wire appeared to be fraying, so after cleaning and resoldering the connector the cars performance was vastly improved, so I think you have solved this one, thanx again, Pete.
vivapete3
GT Viva
GT Viva
 
Posts: 128
Joined: Sat Oct 08, 2016 10:56 pm
Location: Stoke

Re: Misfire in 1256 engine

Postby vivapete3 » Thu Jun 01, 2017 2:11 am

rattlyolddt wrote:Hi Pete

I as you started down the line of electrical fault finding, as initially the misfire was very violent.

Having fiddled and replaced bits gradually, it has improved, much like you.

I am still unsure if my LT side of things is earthed correctly though.

Good luck!

Hi thanx for your reply, I have now checked my LT wire closely and the dizzy end appeared frayed so after cleaning the connection and resoldering , the car's performance has been dramatically improved, so hopefully I've sorted my issue, good luck with your repairs, if I hear of any other tips / advice I'll message you, cheers, Pete.
vivapete3
GT Viva
GT Viva
 
Posts: 128
Joined: Sat Oct 08, 2016 10:56 pm
Location: Stoke

Re: Misfire in 1256 engine

Postby rattlyolddt » Thu Jun 01, 2017 7:49 am

ADRIAN wrote:Check the dizzy cap. ALL new caps that you can buy are slightly faulty in that they do not fit snuggly onto the top of the distributor. The locating ring moulded on the underside is too wide, and needs careful filling down, all way round to fit correctly onto the top of the dizzy (preferably with a little bit of play.) If used straight out of box, the cap fits VERY tightly or even sits skewiffy, and the two strong side spring clips can break the plastic, a hairline crack in the plastic thats very difficult to see. Look with magnifying glass. But this crack will produce a misfire when the engine warms up .
Adrian


Thanks Adrian, I had heard that. However my new one does seem to fit loosely, I checked before I clipped it on. It rotates either way if you try.


[/quote]
Hi thanx for your reply, I have now checked my LT wire closely and the dizzy end appeared frayed so after cleaning the connection and resoldering , the car's performance has been dramatically improved, so hopefully I've sorted my issue, good luck with your repairs, if I hear of any other tips / advice I'll message you, cheers, Pete.[/quote]

Cheers Pete!
User avatar
rattlyolddt
SL Viva
SL Viva
 
Posts: 76
Joined: Mon Feb 13, 2017 12:44 pm
Location: Midlands / South east

Re: Misfire in 1256 engine

Postby rattlyolddt » Thu Jun 01, 2017 7:52 am

I went for a drive last night to run an errand, and had to take the Viva for one reason or another.

It was hesitant and missing under load on for first 5 miles, as I expected, and i drove very delicately on very partial throttle.

On the way home, I drove back and it seemed like the problem never existed!

I'm curious to see what it's like once cooled down.
User avatar
rattlyolddt
SL Viva
SL Viva
 
Posts: 76
Joined: Mon Feb 13, 2017 12:44 pm
Location: Midlands / South east

Re: Misfire in 1256 engine

Postby 1972nail » Thu Jun 01, 2017 10:16 am

1972nail wrote:Are you sure it's an ignition problem? Could be fuel.....


Just bringing this up again......
Editor of the VVOC Magazine ReVival

"When you have a Firenza like mine, who needs any Minis?" copyright David Maxwell 1979.
User avatar
1972nail
Old Nail
Old Nail
 
Posts: 3355
Joined: Sun Aug 07, 2011 4:16 pm
Location: Ballymoney Co Antrim - some say....the World's best place to live!

Re: Misfire in 1256 engine

Postby droopsnoot » Thu Jun 01, 2017 10:27 am

vivapete3 wrote:I checked the LT wire and the dizzy end of the wire appeared to be fraying, so after cleaning and resoldering the connector the cars performance was vastly improved


Excellent news. I guess we have to remember these wires are 40+ years old now, so it's inevitable that some attention might be needed.
My real name: Mike. My web site: http://www.firenza.net

My stuff for sale: http://www.firenza.net/forsale.shtml
droopsnoot
Old Nail
Old Nail
 
Posts: 2309
Joined: Mon Oct 31, 2005 2:08 pm
Location: Cheshire

Re: Misfire in 1256 engine

Postby rattlyolddt » Thu Jun 01, 2017 10:51 am

1972nail wrote:
1972nail wrote:Are you sure it's an ignition problem? Could be fuel.....


Just bringing this up again......


Hi David, I will order a rebuild kit tonight and look at the fuel pump! :goodideasign: :thanx:
User avatar
rattlyolddt
SL Viva
SL Viva
 
Posts: 76
Joined: Mon Feb 13, 2017 12:44 pm
Location: Midlands / South east

Re: Misfire in 1256 engine

Postby Fred Dukes » Thu Jun 01, 2017 5:32 pm

Nice one Pete - should be ok for Tatton Park then for the weekend :P
CHAIRMAN and general dogs body and now Acting Parts Coordinator! (again :roll: )
User avatar
Fred Dukes
Club Chairman
 
Posts: 6319
Joined: Sun Oct 30, 2005 10:13 am
Location: Newport, Shropshire

Previous

Return to Electrical help

Who is online

Users browsing this forum: No registered users and 2 guests

cron