* DPC MODULE & INJECTION PUMP CONTROLLER *

#61

Im gona bump up this old topic....

I just bought a 81 datsun...and the previous owner has a cable to turn the truck off. it wont turn off by the ignition switch. Seems like it is always in the "RUN" position. the dpc connector is currently unplugged..and i was wondering if its possible to run a 3 position toggle switch in the cab for OFF RUN and START? If not..whats the best way to make this work again?

When i plug the connector in where its supposed to be..the actuator turns to OFF. We got lucky and put some power to one of the wires and got it to go to the run position again. Havent fooled with it since and im looking for some more knowledge..

#62

I haven't owned the sd's.

That said, there is a generic check I'd think would be needed first: The ignition switch. If that doesn't provide all the proper connections and switching, the oem setup won't work. I view the things as the revenge of the Gawd of Used Cars but there's no getting around them if you want OEM functions.

Next of course is the module. It sounds like that might function provided the right inputs.

To do the ignitions switch checks, you _might_ find some pin-outs and voltages here using "search". However, I suspect you will need to reference the FSM. With old vehicles "the book" is really necessary and usually you can get it on ebay for $20-30.

Best luck. Rufus

#63

Since you have a cable, either the DPC and/or the IPC is bad. If you can buy new parts they are hundreds $$ each.

I believe you can use a 3 way toggle. Wiring diagrams are here somewhere for the controllers.
They are also in the repair manuals.

The cable is an inexpensive way around the problem. You will not find many SD's without the cable .

#64

Ok thats a good start. So what exactly is the cable doing? Its not moving it to the OFF position..it sounds like its choking the fuel?

#65

The injection pump lever has three positions.
Off-no fuel flow. Run-standard fuel flow. Start-excess fuel flow.
We are only interested in off and run. The lever is designed to always return to the run position. Moving the lever to the off position is towards the firewall which is the direction all the cables pull it to.

#66

When i pull the cable the lever doesn't move, its always in the run position. Sometimes i give the pedal a little tap to start it in the mornings.

The wires and plug int hat controls the DPC is not plugged in.

#67

You must disconnect one end of the rod (shown in top picture) connecting the IPC to the injector pump. I suggest doing so at the IPC and allow the rod to hang.
One of my trucks is this way.

How do you shut it off now?

#68

Disconnect the rod that allows it to switch positions?

The truck shuts off with the pull of that cable..it sounds like its choking it..like an old tractor.

#69

XDAC wrote:Disconnect the rod that allows it to switch positions?

The truck shuts off with the pull of that cable..it sounds like its choking it..like an old tractor.

Yes, disconnect the rod. The power is already disconnected (bottom picture) so the controllers are not working.

That about sums it up.

I think disconnecting the rod will allow the cable to pull easier. If not, reconnect it.

#70

Greetings, Gents!

This forum is the 1st place & you are the 1st folks I've "seen" that not only acknowledge the abundance of Datsun diesels, but make sense of the controls. Plus, you broke the turbo barrier!
1st owner had no clue about maintenance, so I get odd surprizes. Biggest is the FSM's lack of data on the Inj Pump.
WHERE did you get all this data? (I'll be chasing threads for months to sort it.)
Why not attach the go pedal to the Inj Pump lever like other diesels?
WHY is there a governor on them?
WHO successfully welded his exhaust manifold? Is he the one who mirror polished it? Got a pile of questions about that.
Thanks, guys.
Clear sailin',
Cmdr. Ron

#71

XDAC wrote:When i pull the cable the lever doesn't move, its always in the run position. Sometimes i give the pedal a little tap to start it in the mornings.

See the rod running down from the bellcrank to the IPC motor?
The image below is from this first post in this thread.

It connects the IPC motor to the IP fuel control bellcrank. If you're going to use a manual cable, you have to disconnect that rod.

XDAC wrote:We got lucky and put some power to one of the wires and got it to go to the run position again. Havent fooled with it since and im looking for some more knowledge.

The testing procedure is in the FSM, part of which is copied in this post.

dn29626 wrote:I believe you can use a 3 way toggle. Wiring diagrams are here somewhere for the controllers.

I put the basic diagram on how to do that (install a switch to control the fuel mode) in that same post linked above.

dn29626 wrote:You will not find many SDs without the cable.

I disagree. While one of my several SDs had a cable, all my others had the OEM system in place. They can be diagnosed when they're not working, and the OEM system automatically shuts down the engine in the event of low oil pressure. If you read this thread from the beginning, several common weak areas are explored, and ways to fix them discussed.

The cable retrofit, as it's usually installed, doesn't allow the IP to be put into the excess-fuel Start mode. If you live in a cool clime, as do I, that doesn't work well for cold starts. The OEM system does.

#72

The cable retrofit, as it's usually installed, doesn't allow the IP to be put into the excess-fuel Start mode

It's not hard to install it so it does allow the excess fuel mode. I adjusted the positioning of the control cable mounting on my pump to let the control lever all the way forward for enriched mode. Once running, I pull the cable out to a predetermined scribed line which marks the normal running position of the control lever on the pump. Twist to lock, and it's set to drive. To turn off, unlock and pull all the way out. Never had a problem with it yet.

N_R

#73

That's why I said, " . . . as it's usually installed . . . ". I've had several trucks brought to me with the cable setup, and every one was installed such that excess-fuel mode was not available.

TajMan · #74

'81 Datsun Diesel 720 here,
from the information I found in this thread, my DPC box ended up testing as bad.

#75

ok, jOE... JUST BRING IT HERE & WE'LL USE IT TO FIX MINE. ok?

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* DPC MODULE & INJECTION PUMP CONTROLLER *

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