Hi I have a 1999 1.8 ford focus its misfiring on cylinders 1
Remove the top cover on the
valve cover concealing the coils. Remove and inspect the spark plugs,
and replace as necessary. Start the engine and see if the miss has been
eliminated. If the miss is still there, a problem could also exist in
the wires or coil or even the fuel injector, which will all need to be
addressed as the diagnosis progresses. A fuel injector will cause the
same type of a miss if it sticks.
Mist the spark plug wires, and
watch for evidence of arcing to the cylinder head cover. This will
indicate a bad wire. If this is visible, then replace the spark plug
Turn the engine off, and loosen
the wires at the coil by giving them a twist and pulling them out of the
coil. Leave them on the coils--you just want to loosen them a bit to
make the next step easier.
Start the engine. Using a pair
of pliers with insulated handles, pull one plug wire out of the coil at a
time and watch for a noticeable drop in engine RPM. The cylinder that
has no drop or noticeable decline in RPM is the one causing the miss.
Also when the wire is removed, watch for a good spark at the coil to the
wire when the wire is held close to the coil. This could indicate a
bad coil if the plug wire checks out fine.
Check the suspect wire with the
Ohm meter, and test for continuity through the wire. If there is
continuity, the miss is still present and there is no spark to the wire
when it is removed from the coil, replace the coil.
Check the fuel injectors. If the
plugs and wires are good and there is a spark at the coil to wire test,
then checking the injectors is the next step. If this is fine, then a
compression test should be done to locate an internal engine problem.
Start the engine, and remove the electrical connectors to the fuel
injectors one at a time and listen for a significant engine RPM drop. If
one cylinder is found to make no difference or very little in
comparison to the others, replace the injector.
Oct 19, 2011 |
2000 Ford Focus