Back firing (I think!)

Post by **AndyPap** » Wed Apr 12, 2006 1:23 pm

Hi all! It's a while since I last posted, but I've finally dragged my Minor out of the garage after it's winter hibination (last used in October) and I'm pleased to say it started first time, and idles nicely at 800rpm once warm.

The problem, once I start driving, it coughs and splutters when I'm accelerating in 2nd and 3rd occaisionally backfires, and it ran fine last summer when I bought it. (It's got a 1275 A+ engine and a HIF carb, if that makes any difference).

Any thoughts about what's causing in and how to fix it?

I'm sure this is the easiest question in the book, so appologies for being a numpty!!

Andy

Post by **minor_hickup** » Wed Apr 12, 2006 3:33 pm

I had a similar problem that kept getting worse. Sounds like ignition, is the timing right? When I had this i changed plugs, points, condesor, dizzy cap and rotor arm to no avail. I turned out to be one of the HT leads. Hope this helps.

Post by **Cam** » Wed Apr 12, 2006 3:46 pm

If it is actually 'backfiring' then it does indeed sound like ignition and/or a weak mixture. Check ignition first then carb. It would not hurt to give it a full ignition service: cap, arm, points, condenser, leads & plugs.

Post by **chrisd87** » Wed Apr 12, 2006 4:05 pm

Also take a look at the fuel pump - poor running and spluttering under acceleration might suggest that it's not getting enough fuel through to the carb.

Post by **bmcecosse** » Wed Apr 12, 2006 9:05 pm

Points/rotor arm/dizzy cap - clean them all up - and the spark plugs. back firing is un-burned fuel igniting in the exhaust - so it suggests poor ignition which is allowing the fuel to go through without burning.