Mystery Misfire

[Trevor Triumph]

I'm not sure what is happening but the Spitfire runs very well. Then for no apparent reason it begins to miss. I thought it was an ignition problem so reinstalled the points after the electronic ignition produced the misfire. While trying anything to get home I pulled the choke on fully. The engine became smooth again although I use more fuel. What I thought was an ignition misfire could be a fuel matter. Any ideas? T.T.

 

[ObiRichKanobi]

Parially clogged fuel filter or weak fuel pump?

 

[Darwin]

Vaccuum leak

 

[sammyb]

Check all the standard stuff:
1)Fuel Filter
2)Make sure all the spark plugs are tight
3)Check all the plug wires and all the wires to the coil are tight.

 

[waltesefalcon]

I am gonna agree with Darwin. When my spit had a very similar problem a couple years ago it was a cracked vacuum line.

Cheers,

Walter

 

[Trevor Triumph]

Thanks for the suggestions. I made sure the plugs were in tight enough the filter was new. I put a hose clamp on the vacuum line and the problem has gone away for now. I still need to put some moe miles on it to be sure. Thanks again! T.T.