Expert: Kevin Pilotte - 1/8/2010

Question
I have a 1975 Pacer with the 4.2L 258 I6 and a three speed manual with overdrive.  The car had been running rough the last few days so I replaced the spark plugs (gapped to .035) , wires, and rotor.  After I put the new parts in the car refused to start.  I have the shop manual so I know the plug wires are in the right order (1-5-3-6-2-4, clockwise) and the car still refuses to start.  Sometimes it backfires but it won't start or fire very often (if at all).  Also when the engine is cranking it will crank then stop then start again.  I am at a complete loss.  As the car was running right before I put the new parts in and now it won't do anything.

Answer
Three things are necessary to get your Pacer running, and they must occur in the proper order.
1) Compression. Perform a compression test or cylinder leakage test. Compression should be high and within 15 psi of each other.
2) Spark. Remove the coil wire from the distributor cap, hold it 1/2" from the engine block, have someone crank the engine. You should have a strong spark.
3) Fuel/air. You can look down the throat of the carburetor with the engine OFF; operate the accelerator linkage; you should see a strong stream of gas shooting into the venturi.
If the everything above is working like it is suppose to, check for vacuum leaks, ignition timing, carburetor adjustment, and valve timing.
The 75 AMC ignition system had problems with the pickup assembly in the distributor. This would result in a loss of spark. If this is a problem with yours, you might have to replace the distributor.
Good luck.