TurboedMJ Posted February 12 Share Posted February 12 I was driving my MJ today (It's been my daily for about 6 months) and noticed that it misfires or bogs down under load. It will get up to about 2500rpm and misfire and lose power badly, until about 3500-4000. This issue just started today, and I replaced the rotor in the distributor a couple months ago. Any thoughts? I'll post a video if I can get one Quote Link to comment Share on other sites More sharing options...
TurboedMJ Posted February 12 Author Share Posted February 12 The first one is a rough idle that it just the developed. The Google link is a driving video. At the end of the driving video I was going up a slight hill in 1st most of the way. https://photos.app.goo.gl/vC2PVz1q228MSh5q8 Sunday at 13-25 video.mp4 Quote Link to comment Share on other sites More sharing options...
TurboedMJ Posted February 12 Author Share Posted February 12 Checked the plugs (they're clean) and I'm going to change the injectors tomorrow because it has good spark and injectors are cheap Quote Link to comment Share on other sites More sharing options...
pizzaman09 Posted February 13 Share Posted February 13 How is the condition of the ceramic insulators on the plugs, any cracked insulators? Is the distributor aligned correctly so that spark doesn't have a giant gap to jump? Are the manifold bolts tight, a good intake leak could cause misfires. Quote Link to comment Share on other sites More sharing options...
cruiser54 Posted February 13 Share Posted February 13 Plugs, wires, cap and rotor replaced together at 30,000 mile intervals. Have you completed Tips 1,3,4 and 5 on my website? Quote Link to comment Share on other sites More sharing options...
TurboedMJ Posted February 15 Author Share Posted February 15 On 2/13/2023 at 4:13 AM, cruiser54 said: Plugs, wires, cap and rotor replaced together at 30,000 mile intervals. Have you completed Tips 1,3,4 and 5 on my website? I haven't. Going to replace the plugs and wires this or next week sometime and just replaced the rotor a couple months ago. Quote Link to comment Share on other sites More sharing options...
TurboedMJ Posted February 15 Author Share Posted February 15 I replaced the injectors today and it's running a lot better, still has the occasional misfire when beginning to accelerate but that disappears quickly. Quote Link to comment Share on other sites More sharing options...
TurboedMJ Posted March 4 Author Share Posted March 4 Ok so I replaced the plugs and wires, and checked the compression at the same time. These are the numbers. I live at 500 ft of elevation and it's not actually turboed 😄 haven't used the tips yet. Quote Link to comment Share on other sites More sharing options...
TurboedMJ Posted March 4 Author Share Posted March 4 When I replaced the cap I noticed the replacement rotor was pretty dirty, does that signify anything? Quote Link to comment Share on other sites More sharing options...
cruiser54 Posted March 4 Share Posted March 4 Cap, rotor and wires are maintenance items. I would try a different compression gauge. Quote Link to comment Share on other sites More sharing options...
TurboedMJ Posted March 4 Author Share Posted March 4 That was a rental one from AutoZone. I'll buy a better quality one. Quote Link to comment Share on other sites More sharing options...
pizzaman09 Posted March 4 Share Posted March 4 Those compression numbers would be sad for a flat head Briggs and Stratton. I would expect to see numbers between 110 and 150 depending on gauge with the desire that they are all relatively close to each other. Quote Link to comment Share on other sites More sharing options...
pizzaman09 Posted March 4 Share Posted March 4 Check to see if your intake manifold and exhaust header bolts are tight. You might even be missing some bolts. Quote Link to comment Share on other sites More sharing options...
TurboedMJ Posted Friday at 12:44 AM Author Share Posted Friday at 12:44 AM Turns out it wasn't misfiring, just starving of fuel. Replaced the fuel pump and filter and it's good to go. Quote Link to comment Share on other sites More sharing options...
pizzaman09 Posted Friday at 12:10 PM Share Posted Friday at 12:10 PM 11 hours ago, TurboedMJ said: Turns out it wasn't misfiring, just starving of fuel. Replaced the fuel pump and filter and it's good to go. Fantastic! Been there before with another car. Quote Link to comment Share on other sites More sharing options...
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