how to test the crank sensor

[damnford]

i have the sensor off the engine because of no spark. i tested it for an a/c signal, nada, i tested it for continuity across the terminals, nada, i waved a piece of metal across it and nada the tach doe not twitch when the engine cranks. what other tests can i do?

 

[waywaay]

easiest to test while installed on the engine, so pop it back in and check for signal pulse while cranking (I think the lack of continuity across the terminals is a good sign as far as health of the sensor) anyways check for pulse at the sensor itself and also at the pcm side of circuit

you most likely need to check the sensor’s circuit As that is the most likely failure point not the actual sensor...two wires route up from sensor past the water pump then by the thermostat housing (easily fudged up when water pump is replaced for example) and into a bigger loom and eventually to the pcm, check both wires for continuity

 

[damnford]

i will do that first thing this morning, ut i am thinking the sensor is shot. it was a used one from the wrecking yard since my ex son in law stole most of the new parts off of my truck.

 

[damnford]

it was bad so i bought a new one as well as a ign module from pull and save now I have spark and if I squirt starting fluid in the throttle body it starts for a sec. i ordered a new fuel pump it should be here soon.

 

[waywaay]

sweet, you had it figured out to begin with...i assume you don’t hear the pump priming when key ignition on (if you do hear the pump you need check for a clogged filter and/or for pulse at injectors) ...anyway make sure you have power at the pump harness before you bother dropping the tank and such

also, personally I would Only replace the pump itself (motorcraft i.e. walbro, nothing else will last except maybe a carter) not the entire assembly, reason being the auto store assemblies are chintzy so better off with original unless your fuel gauge not working (in that case the Carter assemblies and only Carter appears Equivalent to motorcraft)

 

[damnford]

i already ordered a new pump. not the whole assembly just the pump and I think it was walbro. the relay was iffy so I changed it out for a junkyard one that says Motorcraft on it. i changed the other to as well while I was in there. the new pump should be here soon. and yes even though I just changed the filter two years ago i am changing it again anyways. eventually, i will change the injectors as well.