You're right; I'm probably wrong. This occurred on a friend's Astro Van with a 4.3L engine, but as I recall, only one injector quit at a time. When Keeny K continues, he's going to look for what both injectors have in common when they both quit at the same time. If that is fuel pump / supply-related, the fuel spray will drop off relatively gradually as fuel pressure bleeds off. This could also be sensor-related, in which case the spray would quit instantly as though a switch had been flipped.
Next, if you look at the very top of the diagram he posted, both injectors are fed from the same 10-amp fuse. A poor connection there, up to the splice, would affect both injectors, so that's a good suspect too. After that, each injector has its own driver circuit in the computer. It's not likely both of those would quit at the same time. Here's where what the two driver circuits have in common would-be better suspects. That could be a timing sensor input or some of the circuitry inside the computer. In most cases, a failing timing sensor, (crankshaft position sensor or camshaft position sensor), will also cause loss of spark and injector pulses at the same time. All you can see visually is the loss of injector pulses. You might consider connecting an inductive pickup timing light to a spark plug wire to see if spark is being lost at the same time. On newer models, loss of both spark and injector pulses cause around 95 percent of crank / no-starts or intermittent stalling. Loss of just spark or just fuel accounts for only the other five percent.
Saturday, February 12th, 2022 AT 6:12 PM
