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351W Misfire

Old 06-01-2009, 06:13 AM
  #1  
Anth
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Default 351W Misfire

Ever get that sinking feeling when you know its missing but cannot find the fault?

The most annoying thing about it is that its intermittent, sometimes its real bad other times you dont notice it.

The engine has a set of brand new plugs, it has a new twin spark distributor (believe its a racing one) And the ignition has been taken back to points.

On saturday we started the car and she idled nicely but a little fast, we made a few adjustments to the idle speed etc and noticed the automatic choke was not opening fully, the engine stalled, when we restarted we kept hearing pops from the exhaust, we are taking this to be unburned fuel from a cylinder thats down. As I said earlier, it pops runs ok for a few revs and then will double pop, run OK for a bit pop etc etc etc

Any common areas to check?
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Old 06-01-2009, 08:53 AM
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2+2GT
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First thing I'd do is watch it run in total darkness. Any spark leak will show easily.
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Old 06-01-2009, 09:06 AM
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cpartridge
 
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Did the problem start after any of the parts chages you mentioned? First look for anything obvious like loose or damaged plug wires, also check for a cracked plug (it is easy to do) Check all distributer connections. Points can drive you crazy so check them as well.
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Old 06-03-2009, 04:30 AM
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Originally Posted by cpartridge
Did the problem start after any of the parts chages you mentioned? First look for anything obvious like loose or damaged plug wires, also check for a cracked plug (it is easy to do) Check all distributer connections. Points can drive you crazy so check them as well.

Thanks for the replies guys, both were helpfull.

Heres what we did, removed plugs, all blackened.
We opened the distributor cap, and noticed that the points gap was huge and that one set was open the other set was closed.

We opened both set of points at about 6degrees BTDC.

put plugs back in
car would not run

plugs back out, scratched head, drank coffee, scratched head some more.

Misread firing order on engine block and re-routed the HT leads
Car would not run
Scratched head
plugs out

scratched head, checked internet, realised firing order was screwed up, reset firing order to correct one.

Car wouldnt start
Threw a fit, stomped about for a while, drank coffee and scratched head and ****.

Checked for vacuum followed by pressure to ensure we were on the compressions troke on pot 1.

Lifted distributor out slightly enough to turn rotor arm towards cyclinder one with the engine at TDC.

Put it all back together

Car started and cut out.
Kicked the neighbours cat, scratched head, scratched **** and scratched *****.
Re ordered the firing order on dissy cap to move them all counter clockwise one terminal

car started and ran rough.

Jumped for joy

killed ingnition, tweaked the points and re-started, car now sounds like a Mustang and not an asthmatic in the london marathon.

Drank beer!
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