Atozone Tonine Posted March 22, 2013 Share Posted March 22, 2013 Has anyone had this happen before? - Cruising along at a steady 2000 rpm, not doing anything unusual and the engine just stopped firing and I coasted to a stop. The details: The battery seems to be fine - I have power. The starter is cranking fine. I have fuel, and its going into the carb fine. I cant see any loose wires. How can I test to see if it is the distributor or coil or spark plugs? FYI - I have a 71 240Z with a SBC 350 my distributor cap shows some signs of melting on the outside, but I thought it was just cosmetic, and was that way before it was installed. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted March 22, 2013 Share Posted March 22, 2013 If you remove the coil wire from the cap and place that end close to a ground, crank the engone over and you should see spark. If you don't hear or see a spark, start checking the distributor. A lot of times when the module cools down the engine will then start and run normally. If the engine has an HEI distributor it may be the HEI module, Possibly the pick up also. Quote Link to comment Share on other sites More sharing options...
Atozone Tonine Posted March 25, 2013 Author Share Posted March 25, 2013 (edited) ok, i did that... and had no spark when i held it near the block Here is a pic of inside the distributor cap.. I'm pretty sure its not supposed to look like this. It looks broken in the middle and i think i can see the little copper button down inside the distributor. What is the best distributor i can get from summit for a 72 Chevy small block v8? Edited March 25, 2013 by Atozone Tonine Quote Link to comment Share on other sites More sharing options...
3ryce Posted March 25, 2013 Share Posted March 25, 2013 wait you removed the coil plug from the dizzy cap. and held it close to the body and didnt notice spark? i would not think your dizzy is bad. i would go for the coil or something on that side. the coil gives the spark and if your not getting a spark before the dizzy then your dizzy is good still. Quote Link to comment Share on other sites More sharing options...
30 ounce Posted March 25, 2013 Share Posted March 25, 2013 Yup, the center pin in that cap is toast. Just go to your local parts store and get a new cap & rotor. Put everything back together & see if it works. If not then pull the center wire off hold it 1/2" away from the block and have someone else crank the motor whiel you check for spark. If no spark it could be bad coil or worn points (if you have them). No matter what you will need cap & rotor. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted March 25, 2013 Share Posted March 25, 2013 You haven't mentioned what type of ignition system you're running. Your cap doesn't look HEI but if you order a complete HEI unit from summit it would be an easy install. Quote Link to comment Share on other sites More sharing options...
Atozone Tonine Posted March 25, 2013 Author Share Posted March 25, 2013 (edited) wait you removed the coil plug from the dizzy cap. and held it close to the body and didnt notice spark? i would not think your dizzy is bad. i would go for the coil or something on that side. the coil gives the spark and if your not getting a spark before the dizzy then your dizzy is good stilI I was thinking the same thing, but the cap looks bad and is broken anyways... Im not sure if it is possible to have 2 failures at the same time, but I need to get a new cap anyways. I was holding the center plug near the block and the intake manifold.. I thought this should be a good ground with bare metal.. but no, I did not see any spark. I will try again with another spot and see what happens. You haven't mentioned what type of ignition system you're running. Your cap doesn't look HEI but if you order a complete HEI unit from summit it would be an easy install. Here is a pic of my coil.. It is a Mallory Promaster. I need to check the part number to be able to tell you what kind it is. Is an HEI distributor better in any way? Edited March 25, 2013 by Atozone Tonine Quote Link to comment Share on other sites More sharing options...
Miles Posted March 25, 2013 Share Posted March 25, 2013 (edited) Before you waste a lot of time and money, you need to methodically go through the primary and secondary ignition system components. Do you have a Chevy Haynes manual that covers the SBC engine? You will need one if you want to properly diagnose problems and maintain the engine. Any Chevy manual for the year of the engine you have will work. In addition to the cap, have you checked for voltage at the coil? If you have a spare coil you can swap it in to see if it improves anything. Yes the HEI is an improvement, but make sure that you just don't have a points, loose wire or power problem after checking the coil and replacing the cap. Note that the HEI may require more space so check your firewall clearence and your stock Tach will not work with the HEI distributor. Google is a good way to obtain information on SBC engines. There many Chevy websites that you should research and bookmark for future maintenance/performance issues. Edited March 26, 2013 by Miles Quote Link to comment Share on other sites More sharing options...
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