ohming out crank sensor

Big_Mike

Registered User
whats the ohm range for a good crank sensor?
my 89 has a real weak spark and wont start
previous owner said it would run for about 20 mins then die
it also cranks good then stops like it is firing on the compression stoke as the piston moves up and im afraid of bending a rod
i want to be sure of the problem since four kids make the cash disappear rather fast in my home
any input or ideas would help a lot
 
The crank sensor is Hall Effect transducer. I am not sure you can get a meaningful resistance reading from it. But with that said....it either works or doesn't and when it doesn't you have NO SPARK not just a weak one.
 
It may be as simple as the DIS overheating.. Take if off clean up the white "heat sink grease" and re-apply. Any "pc/electronic parts" type store usually sells it, radio shack etc. It is used on the pc cpu the heat sink as well. The DIS would cause weak spark, once off you can take it in, some autoparts stores test it for free.
 
If the crank sensor was bad you would have ZERO spark, not weak spark. The DIS module generates the energy for the spark that is multiplied by the coil pack. I'd be thinking DIS before coil pack.

Do you get any codes for key on, engine off?
 
Minor correction there Mike. The DIS does not "generate" anything. It provides an electrical path to ground for the individual coil packs and switches between them as necessary to fire the correct pair of plugs at the correct time. It also limits the maximum amount of current that can flow to like 5.5 amps. But yes if there is added resistance in that current path it WILL limit current flow in the coil packs and result in less spark energy.
 
thanks guys!
ive also thought cam sensor
will a cam sensor and coil pack off of a split port taurus work for the sc?
i know were these are for free and if the will work ill keep em for spares
as far as the dis ill try the heatsink grease
any one know of a good sc person in the western kentucky / owensboro area
im afraid i might be the only one with any knowledge about these cars around here.
i just dont know about the electrical side of things
 
Minor correction there Mike. The DIS does not "generate" anything. It provides an electrical path to ground for the individual coil packs and switches between them as necessary to fire the correct pair of plugs at the correct time. It also limits the maximum amount of current that can flow to like 5.5 amps. But yes if there is added resistance in that current path it WILL limit current flow in the coil packs and result in less spark energy.

I thought there were power transistors in the DIS that were part of the circuit to the coil pack to set the proper current/voltage level to trigger things. Maybe they are just there to fine tune things?

Either way, for our original poster, you can check the cam sensor's role in any problem by disconnecting it. If the engine computer can't find the cam sensor, it'll go into a mode of hunt and peck, trying to figure out what cylinder to fire changing it's guess each time you key on, start, key off. Thus it will seem hard to start since it can take a few tries to guess right. I don't know if the cam sensor off the Taurus will work.

DIS, may or may not work. Can't recall your year, but there is DIS on the 89 through 93 and EDIS on the 94 through 95. EDIS and DIS are not the same. So it depends first on what the taurus is.
 
the taurus would be newer than that
since the cam sensor test doesnt involve a purchase ill try it first
after all the balancer issues im reading about i might as well check that too.
one more question about ignition... has anyone tried making a coil on plug igntion by splitting the coil signal wires? just something floating around in my head and it dont seem too hard to rig up.
 
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