Blame my soft spot for Ford Mustangs for the reason I feel compelled to promote this installment of EDN's Sherlock Ohms, even though its subject doesn't pertain to directly to electronics. Sherlock Ohms articles all focus on troubleshooting problems whether they be mechanical, electrical, or a combination thereof. In this case, the electrical problem - a computer that erroneously caused the engine to run in a lean fuel mixture mode - was caused by a mechanical problem - a clogged PCV device. It has admittedly been many years since I needed to be concerned with a PCV valve because of having a maintenance warranty on my vehicle, but for many decades thence I replaced my own PCV valves as part of a routine maintenance program. On more than one occasion I found the PCV valves to be 'sticky' and causing problems. If all goes as planned, my next vehicle (we only have one at a time these days) will be a vintage pickup truck that has no electronics on it other than an aftermarket radio and DVD player, and a GPS unit. Most likely it will be a pre-catalytic converter model as well (first used in production in 1973).
Posted September 28, 2014