View unanswered posts | View active topics It is currently April 28th, 2024, 6:04 am



Reply to topic  [ 8 posts ] 
 backfiring problems 
Author Message

Joined: July 10th, 2009, 10:28 pm
Posts: 2
Post backfiring problems
My 1987 2CV motor is backfiring. Spitting fire out of the carburetor and seems to be miss firing? I've replaced: Battery, Alternator, Voltage Regular, removed the carb to inspect. When I attempt to increase RPM from idle the motor backfires, spits fire out of carb. H E L P


July 10th, 2009, 10:33 pm
Profile
Firing on two.
User avatar

Joined: February 8th, 2009, 11:27 pm
Posts: 366
Post Re: backfiring problems
Ht leads, coil, points, or mixture i would think. Guys on here know more.

_________________
Image

...Betsy...............Ellie...............Molly


July 10th, 2009, 11:29 pm
Profile YIM
viking bastard
User avatar

Joined: April 18th, 2009, 11:43 am
Posts: 2424
Location: Meneac, Bretagne France
Post Re: backfiring problems
Condenser and contact points

_________________
Image


July 10th, 2009, 11:35 pm
Profile WWW
Agony Aunt - You have a car problem? Speak to Ken

Joined: March 6th, 2009, 1:40 am
Posts: 3675
Post Re: backfiring problems
1/Check and (most probably) adjust your valve clearances.
On unleaded fuel, it's worth setting the valve clearances slightly wider than originally recommended.
0.25mm for the exhausts and 0.2mm for the inlets...

2/ Check inlet tract, including carb base 'gasket' for air leaks.

3/ Check if accelerator pump in carb is working.
It should inject a fine jet of neat fuel into the carb throat when the throttle is opened

_________________
Image


July 10th, 2009, 11:43 pm
Profile

Joined: July 10th, 2009, 10:28 pm
Posts: 2
Post Re: backfiring problems
To prove to you all that I'm ignorant on the mechanics of the 2CV I'll ask the following questions: Do I need to drop the engine out to adjust the valves? With electronic ignition how is timing determined? Could my fuel pump possible be one of the contributors to the backfiring? I inspected the carburator by removing the 6 screws and lifting off the top to determine whether there was anything apparently plugging up fuel flow and it all seems good. I replaced the carburetor then checked the choke function and it seems to do its job. I torqued down the fuel mixture screw until the engine began to wind down and then turned it counterclockwise to increase the fuel and it seemed to attain an acceptable. The motor idles just fine albeit a tad bit rough but not bad. However, when introducing an rpm increase demand the carburetor spits fire, barks and if the rpm increase is sustained the motor will spool down and die with a dying gasp of black smoke out the exhaust. I'd love to drive this machine without parking beside the road in disgust........tomorrow here in France is a 2CV rally and I'm afraid to take the machine out of the barn for fear of ruining the day for my fellow 2cv afficianados (sp?).


July 11th, 2009, 10:25 am
Profile
Firing on two.
User avatar

Joined: December 26th, 2008, 9:40 pm
Posts: 3332
Location: Surrounded by 2cvs...
Post Re: backfiring problems
ajmediator wrote:
To prove to you all that I'm ignorant on the mechanics of the 2CV I'll ask the following questions:


Whilst whoever coined the phrase "The only stupid question is the one that doesn't get asked" had clearly never been on a web forum, these are all sensible questions...

Quote:
Do I need to drop the engine out to adjust the valves?


No. Just remove the front wings - very straightforward - then take the rocker covers off.

Quote:
With electronic ignition how is timing determined?


In exactly the same way as with points - the box is rotated until the right point.

Quote:
Could my fuel pump possible be one of the contributors to the backfiring?


Very unlikely.

Quote:
tomorrow here in France is a 2CV rally and I'm afraid to take the machine out of the barn for fear of ruining the day for my fellow 2cv afficianados (sp?).


Take it along, open the bonnet and look gently puzzled. You'll have four people under there working on it for you in minutes.

_________________
Image
Zookeeper of a miscellany of motorised silliness - from 0.75bhp to 9ft tall - now living life on the road in an old VW.
http://WhereverTheRoadGoes.com


July 11th, 2009, 12:53 pm
Profile YIM WWW
Old Bloke

Joined: May 25th, 2009, 11:39 am
Posts: 685
Post Re: backfiring problems
You might also consider coming on one of our courses, see www.2CVTech.co.uk for details. We do cover all the things listed below.

_________________
Now known as 602

http://www.2CVTech.co.uk


July 11th, 2009, 3:19 pm
Profile
Firing on two.
User avatar

Joined: April 19th, 2009, 7:18 pm
Posts: 328
Post Re: backfiring problems
pound to a penny it's the carb base gasket. But uncle ken is the most wisest of people so I'd pay attention to wot e sez. ;)

_________________
Image


July 12th, 2009, 6:28 pm
Profile
Display posts from previous:  Sort by  
Reply to topic   [ 8 posts ] 

Who is online

Users browsing this forum: No registered users and 356 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

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by STSoftware for PTF.