HI y'all. Still working on this old Ford for my son/dad project. I need a photo or something to help me locate the crank sensor location on our 1985 5.0 EFI F150. I bought the sensor but I'll be darned if I can't find it. You tube does not have a how-to video on the 5.0 location. We have got the starting problem almost figured out in the mornings. We are just shooting a little gas right into the intake hose then it fires right up and after that it starts every time all day long. The bucking it was doing I believe is the crank shaft or cam shaft sensor. So I need to replace it. A photo would be great or a very descriptive text would be wonderful.
Thanks,

Lou

 

From the pictures I'm finding online, what you should be looking for is a big sensor pointing towards the crankshaft harmonic balancer. See the red circle in the picture below. This is likely a magnetic field sensor, not too unlike the door sensors on your home security system (but a little more sensitive). Here's a couple pictures I found:

 

Where does the crank position sensor connect to the wiring harness?

I just picked up a 1996 F150 Eddie Bauer 4x4 5.0 5 speed. PO was in the middle of a water pump change 9 years ago when he stopped working on the truck.

I'm trying to put it all back together but as near as I can tell there are no wires to connect the sensor to. What is worse is that the sensor was not unplugged. The wires were cut right at the back of the plug.

Here's where it gets interesting, the back of the plug and the wires look like they were cut about 100,000 miles ago. It doesn't look at all like it was cut when this was all taken apart. AND the 4 "toothed" wheel that presumably the sensor reads, which sits behind the balancer is cockeyed. So much so that when you rotate the crank shaft two of the four "teeth" contact the timing cover.

I'm confused...

 

That isn't a CPS - it's not used for engine management. It's a misfire sensor, only used for emissions monitoring, and only on '96 trucks. The wiring comes from near the distributor, and runs through a steel guide behind the WP pulley to the sensor, which bolts to the timing cover near the timing pointer & the "Ford" logo in your last picture. This is that wiring:


(phone app link)

The sensor is visible in the NEXT pic.

You can gently & evenly tap the tone ring back into place on the harmonic balancer.

 

Steve83 thanks for the info. I found the wiring (bracket and all) after I had it 99% back together. The tone ring was so loose that I didn't dare leave it on so I removed it. Unfortunately it won't be going back on since I removed it with a hammer and chisel (I didn't have a puller handy and it is made of some pretty soft stuff, a couple smacks and it was broken and off). I'm curious how this sensor helps in determining misfires. It isn't keyed to a specific location on the harmonic balancer so I'm a little baffled at what it could possibly do with what is essentially random information. Also curious where I might acquire a replacement if it comes to it.

 

Here is a description of the crankshaft position sensor for my '82 F150.

 

srick,

If I understand this correctly the pulse ring would need to be "timed" or in a specific known location. If not I don't see how it could indicate when the pistons reach 10 BTDC. The lobes from the pulse ring would need to be in a specific location relative say when the #1 a cylinder is in it's compression stroke and at 10 BTDC. These engines have distributors so I don't know if/how the computer would have this information.

 

No, that's not how the '96-only misfire sensor works. It's just a time signal - not location. The EEC watches for sudden changes (longer gaps between pulses) in the sensor's output frequency. It doesn't matter at what point in the crank's rotation the pulses occur - only that they occur regularly.

...and I've never seen a pre-'97 F150 with a CPS. Certainly not an '82. I think some cars used that system, but I've never found an old truck with anything other than a common distributor.

 

My '82 has a CPS, it is located at about the 9 o'clock position referenced from the front adjacent to the harmonic balancer. I doubt it is being used, the previous owner modified the ignition circuit on this truck quite a bit.

According to the description the frequency output provides position and speed information to the ECA to allow it to set the timing advance. In order for the computer to calculate phase it must have a reference point, I would guess one of the 4 points on the pulse ring is designed to be the reference.

 

Not on the '96.