Expert: Brad Sears - 3/25/2011

Question
QUESTION: My impala won't start. I have replaced the cap, rotor, points, condensor, plugs, wires and coil.  It turns over but won't fire. Any suggestions?  Mark

ANSWER: A gasoline engine needs three things in order to start. Spark at the correct time, fuel delivered to the cylinders, and compression. Now, did this happen after you replaced all the mentioned items or did it quit and the parts were replaced to try to get the engine started? Let me know and we will go from there.


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QUESTION: The car was running prior to although rough it ran.  I also replaced the carbureator with a brand new one.  I pulled the fuel line off to make sure fuel was coming to the carb and it is.  I checked and set the gap on the plugs.

ANSWER: At this point I would go over all the work done on the ignition. If it ran before and does not run now that tells me that some thing got messed up. Did you take the distributor out of the engine to work on it? Did you replace the spark plug wires one at a time? Let me know and we will continue.

---------- FOLLOW-UP ----------

QUESTION: I did replace the wires one at a time and also pulled the electrical diagram to ensure the firing order was correct and all checked out.  As for the distributor, I only removed the cap.

Answer
A couple of things. Remove the air cleaner and hold the choke plate open. Look down into the carburetor bore using a flash light and pump the gas pedal or throttle linkage. You should see two squirts of fuel out of the accelerator pump jets. No fuel then there is a carburetor problem. Next pull the coil wire out of the distributor cap, insert a spark plug into the wire, lay the plug on the engine for a good ground and turn the engine over. There should be a bright blue spark at the plug tip. No spark the problem is ignition. Then remove number one plug and holding your thumb over the spark plug hole bump the engine over till you feel compression. The rotor should be pointed at or near number one terminal in the cap. If not then the wiring is out of order or the timing chain has jumped a tooth or two. Are you handy with a voltmeter? Let me know and we will go further.