* DPC MODULE & INJECTION PUMP CONTROLLER *

[asavage]

The IPC test procedure in the 1982 FSM was posted above, but I repeat it here. I've chopped this page from the FSM to make this a bit clearer (click on image for larger):




Although the FSM says what the expected result of those tests are (the motor should stop at the STOP, RUN, and START positions), I've just tested all three DPCs I have loose. None of them would stop at those places: they will all coast on by and get powered by the next contact, resulting in the IPC running all the time, with fits & starts.

I had one of these do it on the truck, IIRC (the "Bellingham Truck") a couple of years ago.

I have made my very first foray into video (with my clothes on, anyway), and here you can see me testing three DPCs using the OEM test procedure above.

DPC_Testing.wmv (16MiB)

Has anyone else actually used the OEM test procedure on a DPC and had the DPC stop on a dime? I'm really exasperated at this.

[philip]

-SNIP-
Has anyone else actually used the OEM test procedure on a DPC and had the DPC stop on a dime? I'm really exasperated at this.

Do you have a 720 truck to test your DPC's?

[asavage]

I have the engine from the "Bellingham Truck" on a pallet in the back of the "Arlington Truck" with a canopy over all. It's dry, but pretty cozy in there, as there is also a trans, battery, driveshafts, etc. sharing the space. I could bolt one on to it. It's a little hard to get to, but do-able. Weather is not wet right now, but highs in the high 30's today: fairly cold for here. Frost on everything right now. Maybe tomorrow afternoon.

Have you done this test on either of yours, Philip?

[philip]

-SNIP- Have you done this test on either of yours, Philip?

I was away all day yesterday (12/9) at the Long Beach Bike Show.

I do have two DPC-controller. One is on the truck and the other is that one I bought through eBay. The Seller had snipped off the DPC wires right at the plug (dumb). Everything inside is there and now clean but I never tested it. Obviously, the little motor will run continuously when the circuitry does not pass through the wheel / contacts. That's why I suggested plugging your DPC-controller into the truck harnass so that the DPC-module will operate the whole system.

See FSM_1982_EL-047

[asavage]

The Seller had snipped off the DPC wires right at the plug (dumb). Everything inside is there and now clean but I never tested it.

Well, why not?

Obviously, the little motor will run continuously when the circuitry does not pass through the wheel / contacts.

That's the reason for the special hookup during the FSM test shown above: to test the contacts as well as the motor. Test A tests the motor only; Test B further tests the contacts:

• Connect wires for pins 12 & 13 together
• Connect battery Neg to pin 14
• Connect battery Pos to pin 8
• Tap battery Pos to pins 9, 10, 11 to test the motor & contacts

The motor is supposed to stop.

There is no mention of the DPC having to be mounted to perform these tests.

[Nissan_Ranger]

Has anyone else actually used the OEM test procedure on a DPC and had the DPC stop on a dime? I'm really exasperated at this.

Perhaps the momentum of the unloaded spinning armature is sufficient to carry the switching through the 'stop' position and into the next 'run' position?

N_R

[philip]

Has anyone else actually used the OEM test procedure on a DPC and had the DPC stop on a dime? I'm really exasperated at this.

It (almost) stops that quick unless ... you leave out the little drag clip on the end of armature.

[asavage]

@N_R: I have had one do it on the truck.

@Philip: I haven't had any of these three apart. Three missing thrust clips?

[philip]

-SNIP- @Philip: I haven't had any of these three apart. Three missing thrust clips?

You're making me WORK.

Obviously my truck's DPC system works so ... I tested that used DPC controller. This is the one with the electrical plug that had been clipped.





CLICK on this video picture.



Alternate site




Alternate site

[asavage]

I appreciate your work, Philip.

So . . . I have three bad IPCs, all with the same failure mode? Hmmm.

[philip]

I appreciate your work, Philip.

So . . . I have three bad IPCs, all with the same failure mode? Hmmm.

Mmmmm... since the motors work, I doubt you have failures. Maybe two of the pins are in the wrong socket?

Send them all to me. I'll test 'em.

[asavage]

I figured it out -- and your picture was the clue: the motorcycle battery.

I measured my Interstate: 12.8v at rest.

I dragged out an antique Kirkland POS and meaured it: 11.4v.

Repeated a test: DPC stops perfectly at every station. Measured Kirkland battery again: 10.5v.

Connected DPC back to Interstate battery: runs & runs & runs.

Conclusion: use a weak battery or power source to perform the DPC test. Do not use a fully-charged battery.

[philip]

The battery I used is a Yuasa YB18L-A (6cells) battery which right now ... registers at 12.4 volts, using Micronta digital VOM. That size battery is for Honda Gold Wings (1200cc for that particular older model)

[asavage]

Bet it's not 12.4v under the mighty load of the DPC testing.

[asavage]

The DPC Module (black box near right hood hinge, two plugs) is Nissan
No. 19850-31W02, $184 (if available)

The IPC Motor is Nissan No. 19811-36W02,
$359 (if available)