{"id":4125,"date":"2023-02-16T09:29:35","date_gmt":"2023-02-16T00:29:35","guid":{"rendered":"https:\/\/am.denso.com\/plug-global\/?page_id=4125"},"modified":"2023-03-02T11:42:46","modified_gmt":"2023-03-02T02:42:46","slug":"spark-condition","status":"publish","type":"page","link":"https:\/\/am.denso.com\/plug-global\/basic\/spark-condition\/","title":{"rendered":"Conditions that affect the discharge voltage"},"content":{"rendered":"\n<p>The discharge voltage changes drastically with various conditions.<br>The three factors with particularly large impact are the spark plug gap, the compression pressure, and the air-fuel mixture temperature.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Spark plug gap<\/h3>\n\n\n\n<div class=\"wp-block-media-text alignwide has-media-on-the-right is-stacked-on-mobile is-vertically-aligned-top\" style=\"grid-template-columns:auto 35%\"><div class=\"wp-block-media-text__content\">\n<p>The discharge voltage rises in proportion to the spark plug gap.<br>The spark plug gap widens bit by bit as the electrode wears, so high discharge voltage becomes necessary and misfire occurs more easily.<\/p>\n<\/div><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"https:\/\/am.denso.com\/plug-global\/wp-content\/uploads\/sites\/23\/condition_img_01.png\" alt=\"\" class=\"wp-image-4395 size-full\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Electrode shape<\/h3>\n\n\n\n<div class=\"wp-block-media-text alignwide has-media-on-the-right is-stacked-on-mobile is-vertically-aligned-top\" style=\"grid-template-columns:auto 35%\"><div class=\"wp-block-media-text__content\">\n<p>Even for the same spark plug gap, if there are edges on the electrode, discharge occurs more easily.<br>Older spark plugs have electrodes that have rounded, so discharge becomes more difficult and misfire more likely.<\/p>\n<\/div><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"https:\/\/am.denso.com\/plug-global\/wp-content\/uploads\/sites\/23\/condition_img_02.png\" alt=\"\" class=\"wp-image-4396 size-full\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Compression pressure<\/h3>\n\n\n\n<div class=\"wp-block-media-text alignwide has-media-on-the-right is-stacked-on-mobile is-vertically-aligned-top\" style=\"grid-template-columns:auto 35%\"><div class=\"wp-block-media-text__content\">\n<p>The discharge voltage rises in proportion to the compression pressure.<br>The compression pressure is higher for low speed and high load. Sudden acceleration for starting out fits these conditions, so higher voltage is required then and misfire occurs more easily.<\/p>\n<\/div><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"https:\/\/am.denso.com\/plug-global\/wp-content\/uploads\/sites\/23\/condition_img_03.png\" alt=\"\" class=\"wp-image-4397 size-full\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Air-Fuel mixture temperature<\/h3>\n\n\n\n<div class=\"wp-block-media-text alignwide has-media-on-the-right is-stacked-on-mobile is-vertically-aligned-top\" style=\"grid-template-columns:auto 35%\"><div class=\"wp-block-media-text__content\">\n<p>The discharge voltage drops as the air-fuel mixture temperature rises.<br>The lower the engine temperature, the higher the required voltage, so misfire occurs more easily at low temperature.<\/p>\n<\/div><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"https:\/\/am.denso.com\/plug-global\/wp-content\/uploads\/sites\/23\/condition_img_03.png\" alt=\"\" class=\"wp-image-1486 size-full\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Electrode temperature<\/h3>\n\n\n\n<div class=\"wp-block-media-text alignwide has-media-on-the-right is-stacked-on-mobile is-vertically-aligned-top\" style=\"grid-template-columns:auto 35%\"><div class=\"wp-block-media-text__content\">\n<p>The discharge voltage drops as the electrode temperature rises.<br>The electrode temperature rises in proportion to the engine speed, so misfire occurs more easily at low speed.<\/p>\n<\/div><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"https:\/\/am.denso.com\/plug-global\/wp-content\/uploads\/sites\/23\/condition_img_04.png\" alt=\"\" class=\"wp-image-4398 size-full\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Air-Fuel ratio<\/h3>\n\n\n\n<div class=\"wp-block-media-text alignwide has-media-on-the-right is-stacked-on-mobile is-vertically-aligned-top\" style=\"grid-template-columns:auto 35%\"><div class=\"wp-block-media-text__content\">\n<p>There is a tendency for the discharge voltage to be higher the leaner the air-fuel mixture (the larger the air-fuel ratio).<br>If the air-fuel mixture becomes leaner due to fuel system trouble misfire occurs more easily.<\/p>\n<\/div><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"https:\/\/am.denso.com\/plug-global\/wp-content\/uploads\/sites\/23\/condition_img_05.png\" alt=\"\" class=\"wp-image-4399 size-full\" \/><\/figure><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Humidity<\/h3>\n\n\n\n<div class=\"wp-block-media-text alignwide has-media-on-the-right is-stacked-on-mobile is-vertically-aligned-top\" style=\"grid-template-columns:auto 35%\"><div class=\"wp-block-media-text__content\">\n<p>As the humidity rises, the electrode temperature decreases, so the discharge voltage becomes slightly higher.<\/p>\n<\/div><figure class=\"wp-block-media-text__media\"><img decoding=\"async\" src=\"https:\/\/am.denso.com\/plug-global\/wp-content\/uploads\/sites\/23\/condition_img_06.png\" alt=\"\" class=\"wp-image-4400 size-full\" \/><\/figure><\/div>\n","protected":false},"excerpt":{"rendered":"<p>The discharge voltage changes drastically with various conditions.The three factors with particularly large im [&hellip;]<\/p>\n","protected":false},"author":10,"featured_media":0,"parent":464,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_editorskit_title_hidden":false,"_editorskit_reading_time":1,"_editorskit_is_block_options_detached":false,"_editorskit_block_options_position":"{}","footnotes":""},"class_list":["post-4125","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/pages\/4125","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/comments?post=4125"}],"version-history":[{"count":6,"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/pages\/4125\/revisions"}],"predecessor-version":[{"id":5328,"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/pages\/4125\/revisions\/5328"}],"up":[{"embeddable":true,"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/pages\/464"}],"wp:attachment":[{"href":"https:\/\/am.denso.com\/plug-global\/wp-json\/wp\/v2\/media?parent=4125"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}