What is large round thing in valley below fuel filter?

[schamp6497]

Hi, I am trying to put my 97 6.5 back together. I have the engine back in and hooking up all the wires which weren't labeled. My question is what is the round black disk located at the back left in the valley of my 6.5? Its just below the fuel filter and has a two wire connector. So far I have not found the wires that go to it. Thanks for any help. Spencer

[Robyn]

What you are refering to, is likely the oil pump drive/speed sensor.

If you are refering to the item that is where a distributor would be on a regular Gas V8, then thats the real deal.

I have not seen any late 6.5's with the speed sensor back there.
92 and 93 used one to feed info to the tranny controller.

I take it that this is a replacement engine ???

More info please.

Missy

[schamp6497]

Thanks Robbin. Its a 97 6.5 that got rebuilt by Jamie Avant a couple of years ago. Pre cups cracked. I did the head job and now trying to get all the stuff back on the engine. This is a black round disk like object with a wiring plug on it for a two wire plug. It's about 3 inches in diameter and looking from the front, is at the back of the valley and alittle to the left or passenger side. I have looked quite a bit and don't see a wire that fits. Now with that said, its not an electronic engine anymore. It has a marine injection pump with high pop injectors. I turned Jamie Avant loose on the engine trying to get some power. Still a dog. One other thing, I have a 5000 watt generator that mounts under the hood and runs off of a additional pulley added to the crank pulley. Works really well. Its called an auragen generator. It pumps out either 115 or 230 ac. Sitting still or running down the road. Again, thanks for you help. Spencer

[DmaxMaverick]

As Robyn said, it's the oil pump drive with the engine speed sensor (the drive operates the same as a gasser distributor, driven by the cam). Your truck didn't have one, originally, so it won't have the harness connector for it. The oil pump drive comes in several flavors: Vacuum pump (6.2L); vacuum pump w/speed sensor (late 6.2L); blank cap (later 6.5L); cap w/speed sensor (what you are seeing now, for earlier MFI 6.5L w/electronic auto tranny). Since you have it in place, there's no need to do anything with it. You can just ignore and leave it in place. Or, it can be used to drive a tachometer instead of the alternator. This way, your tach won't be dependent on the alternator for the tach signal, negating the importance of the pulley size, making the tach (potentially) more stable and accurate (some modification and calibration required). And/or....use the signal to drive whatever method you are planning for your EFI to MFI system for tranny operation (essentially converting it to the early MFI electronic tranny system). Lots of options (or none) to consider.

If you decide you don't need or want it, it has value. If it appears to be in good condition, I'll buy it from you. If not me, then someone else.

[schamp6497]

Thanks for the replys. Guess I can't find something thats not there. I sure did look. Getting there on the other stuff. Didn't want to move on, securing the fuel filter, grounds, etc and find later that I had to go back and plug something in at that spot. Thanks again.