Misfiring CRV StepWgn : Fixed
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Joined: Dec 2016
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Misfiring CRV StepWgn : Fixed
My 1995 StepWgn, which I purchased new in Japan and has been a fantastic family car, now serving as a backup vehicle in rural Canterbury, NZ, started misfiring under load, when hot. I replaced the plugs tested the leads and then the distributor cap. Tested the injector resistances and noticed minor variances in resistance (around 0.4 Ohms difference : nominal 12.0 Ohms)
Back-flushed the fuel filter using clean petrol and compressed air and noticed quite a bit of dirt coming out (need to replace). Tested spark on each lead with HV test lamp : OK.
I was sure that this was ignition-related and started thinking that I may have to replace the whole distributor.
I was just about to give up in disgust, my one last ray of mental energy kicked in. The plug caps!
As you may be aware, the sparkplugs are set deep in the bowels of the cylinder-head. The plug-caps are long, high-temperature plastic things with rubber seals on the ends. These provide a (water & dirt) seal between the sparkplug insulators and the tunnels. My quick-and-dirty fix, was to spay CRC-556 penetrating oil into the business-ends of the plug-caps. Misfiring under load solved (temporary..) Need to replace plug-caps.
My diagnosis is that the rubber seals have become hardened with extended exposure to high-temperature and high-voltage and, over time, seem to have become slightly conductive on the surfaces.
Back-flushed the fuel filter using clean petrol and compressed air and noticed quite a bit of dirt coming out (need to replace). Tested spark on each lead with HV test lamp : OK.
I was sure that this was ignition-related and started thinking that I may have to replace the whole distributor.
I was just about to give up in disgust, my one last ray of mental energy kicked in. The plug caps!
As you may be aware, the sparkplugs are set deep in the bowels of the cylinder-head. The plug-caps are long, high-temperature plastic things with rubber seals on the ends. These provide a (water & dirt) seal between the sparkplug insulators and the tunnels. My quick-and-dirty fix, was to spay CRC-556 penetrating oil into the business-ends of the plug-caps. Misfiring under load solved (temporary..) Need to replace plug-caps.
My diagnosis is that the rubber seals have become hardened with extended exposure to high-temperature and high-voltage and, over time, seem to have become slightly conductive on the surfaces.
Honda-Tech Member
Joined: Jul 2016
Posts: 241
Likes: 18
From: Maryland
Re: Misfiring CRV StepWgn : Fixed
Good find! My first thought was actually the plug wires. My first car was a 1987 Chevy Camaro IROC-Z that I got for cheap because it would buck like crazy going up hills under heavy throttle. Turned out to be old, worn-out spark plug wires. What tends to happen with the Honda ones is the section between the valve cover seal and the attachment to the spark plug forms micro-cracks and the spark can arc to the head tube walls instead of making it all the way to the spark plug. Sometimes you'll see little white spots on the black rubber at the points where this arcing occurs.
You should post some pictures of this thing! We don't have them here in the US. Is it about the size of a Honda Odyssey of similar year?
You should post some pictures of this thing! We don't have them here in the US. Is it about the size of a Honda Odyssey of similar year?
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