* Won't Shut Down, Smoke, IPC link rod *

SD diesels were widely available in the US in the 1981-86 Datsun/Nissan 720 pickups, and in Canada through '87 in the D21 pickup.

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Zoltan
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Location: Honolulu, HI

* Won't Shut Down, Smoke, IPC link rod *

#1

Post by Zoltan »

Hello Philip, happy to see you back on line...

This is becoming a convoluted EGR system mess on my hands ... My goal is to return oil consumption and running temperature to normal. A bonus would be the de-Californiazation of my engine. I am looking at EC-29 in the FSM and I am not sure how I could get rid off the EGR without affecting the sub-ventory vacuum port and, ultimately, without affecting throttle valve position. It seems to be all connected.


1. EGR vacuum tube is disconnected from the vacuum amplifier. If EGR vacuum tube is connected I get high idle.

2. Idle and engine shut-down seems to be OK now with the EGR vacuum tube disconnected, yet the engine is still running hot (it's steady in the middle).

3. Thermostat is new, water seems to circulate well in the radiator.

4. Just replaced a quart of oil ... (after less then 150 miles). Result of hot running engine?

5. No smoke from tail pipe, but plenty smoke from road draft tube.

6. DPC control looks new, IPC seems to be doing the right thing (only did the quick and dirty check, didn't do the check with a test light and adaptors)

Where do I go from here? Need some help, please! A list of things to do in logical order ... so I can go down the list and report back to this thread
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
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philip
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#2

Post by philip »

Zoltan wrote:Hello Philip, happy to see you back on line...

This is becoming a convoluted EGR system mess on my hands ... My goal is to return oil consumption and running temperature to normal. SNIP

1. EGR vacuum tube is disconnected from the vacuum amplifier. If EGR vacuum tube is connected I get high idle. SNIP
Nice to be back. Opportunistic infection required 7 days of hospital IV antibiotics.

Reconnect the entire EGR system exactly. And I do mean EXACTLY.

From the Coolant Temperature Sensor located on the side of the oil heat exchanger, remove and plug off the hose from the CTS connecting to the metal vacuum line that feeds the pneumatic governor apply side vacuum. Done.

Oil leaves the crankcase by way of:

1. Seals (external leaks)
2. Seals (internal leaks ... valve guide seals and piston rings)
3. Thinned oil due to fuel contamination and/or excessive heat.

These things can be brought about by:
4. Injection timing occuring too early.
5. Running sustained rpm way in excess of max torque rpm range.
6. Oil returns from cylinder head/valve train restricted. (valve area fills with oil).
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
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Zoltan
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Location: Honolulu, HI

#3

Post by Zoltan »

Reconnect the entire EGR system exactly. And I do mean EXACTLY.

From the Coolant Temperature Sensor located on the side of the oil heat exchanger, remove and plug off the hose from the CTS connecting to the metal vacuum line that feeds the pneumatic governor apply side vacuum. Done.
DONE. please check this picture to make sure that I disconnected the right tube.


Image

I noticed a small metal cylinder inside the disconnected rubber tube that, I assume, restricted/controlled the airflow towards the pump. If I cover the hole on the metal tube, the engine will shut down. Is that normal?

I reset the idle to 674 rpm and set the smoke screw. I am waiting for Al's custom made pressure tester he is kindly lending to me to see what compression I get in all cylinders.
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
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philip
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#4

Post by philip »

Zoltan wrote:DONE. please check
Image

IF ... you find that capping the metal line port has anymore than a small effect on idle RPM, then adjust the throttle body idle stop bolt and maybe the smoke setscrew again. This assuming the pneumatic governor diaphragm passes muster.
Last edited by philip 14 years ago, edited 1 time in total.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
User avatar
Zoltan
Posts: 136
Joined: 15 years ago
Location: Honolulu, HI

#5

Post by Zoltan »

As I said, capping the metal tube would shut the engine down. I have a new diaphragm, so I will install it and see if that helps.
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
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Zoltan
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Location: Honolulu, HI

#6

Post by Zoltan »

I took off the daphragm cover, and there was about a tablespoon of motor oil in there. How did it get there? The diaphragm looked intact and soft (no wonder, it was soaking in engine oil).
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
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philip
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#7

Post by philip »

Zoltan wrote:As I said, capping the metal tube would shut the engine down. I have a new diaphragm, so I will install it and see if that helps.
Cap off the metal line spigot (earlier illustration) and then readjust the air butterfly stop bolt so that the engine does idle.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
User avatar
Zoltan
Posts: 136
Joined: 15 years ago
Location: Honolulu, HI

#8

Post by Zoltan »

I capped off the metal line spigott and adjusted the rpm to about 700. The engine immediately started smoking, so I adjusted the "smoker" bolt as well and took it to a test drive. I kept adjusting the smoker screw until I didn't see smoke coming from the tailpipe and the truck was pulling normally.

Now the shut-down problem came back. When I turn the ignition key off, the engine keeps running LOOONG time. If I turn the key ON again and a few seconds later turn it off, then it shuts down. Could this phenomena be due to oil feeding into the combustion chamber from bad valve stem seals? Also, could the oil, I found behind the cover of the pneumatic governer diaphragm, have come from the same source through the EGR?
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
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philip
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Location: Southern California, USA

#9

Post by philip »

Zoltan wrote:I capped off the metal line spigott and adjusted the rpm to about 700. The engine immediately started smoking, so I adjusted the "smoker" bolt as well and took it to a test drive. I kept adjusting the smoker screw until I didn't see smoke coming from the tailpipe and the truck was pulling normally.
I'm curious, ... how much smoke screw adjustment was required in the "lean" direction?

You might find this useful? Venting what should not get vented
Zoltan wrote:Now the shut-down problem came back. When I turn the ignition key off, the engine keeps running LOOONG time. If I turn the key ON again and a few seconds later turn it off, then it shuts down.
A "looong" time is more than 30 seconds? But a repeat ignition switch OFF cycle results in immediate shutdown? I would push aside residual oil ... for now. Turn the engine OFF. While it is still trying to shut down, push the Fuel Control Lever a little bit further to the left (CCW). If that's all it takes to complete the shut down, then the nylon bushings on the rod linking the Fuel Control Lever to the IPC are quite sloppy or your over-run adjustment on the Fuel Control lever pin is not centered in the hole when the lever is in the RUN position.
Zoltan wrote:Could this phenomena be due to oil feeding into the combustion chamber from bad valve stem seals? Also, could the oil, I found behind the cover of the pneumatic governer diaphragm, have come from the same source through the EGR?
Each time I have removed the diaphragm cover, there has been oil present ... the same goop that I had earlier installed on the OTHER SIDE of the diaphragm for "preservative" purposes. The seal between the diaphragm and the housing is not perfect.

Image
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
EvergreenSD
Posts: 70
Joined: 15 years ago
Location: Eugene, OR

#10

Post by EvergreenSD »

My link rod does not have bushings either. Most likely they sawed themselves in half and disappeared long ago. Another interesting
sign of wear on this pump is the way the altitude compensator has
carved a divot into the pin that it can act against.
'82 SD22 720 Kingcab with flatbed
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Zoltan
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Location: Honolulu, HI

#11

Post by Zoltan »

zoltan wrote:
SNIP Now if I set the smoke screw so that the engine runs strong without smoke (or not as much smoke that I can detect in the rear view mirror), then the engine shuts down normally.
********************************************************************************************************************
EvergreenSD wrote: Another interesting sign of wear on this pump is the way the altitude compensator has carved a divot into the pin that it can act against.


Mine looks ecactly the same... so I am not sure it's the works of the altitude compensator. Perhaps it's factory made, it's where the altitude compensator is supposed to grab into ?

OK ... I will get those plastic bushings and see if that helps.
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
User avatar
Zoltan
Posts: 136
Joined: 15 years ago
Location: Honolulu, HI

#12

Post by Zoltan »

DID ANYONE REPLACE THOSE BUSHINGS BEFORE? ACCORDING TO MY PART CATALOG, THE CONTROLLER ASSY COMES AS ONE UNIT (CODE# 16836) AND THERE ARE NO LISTINGS FOR THE BUSHING....

I'LL TRY ACE HARDWARE
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel
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philip
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Location: Southern California, USA

#13

Post by philip »

Zoltan wrote:
EvergreenSD wrote: Another interesting sign of wear on this pump is the way the altitude compensator has carved a divot into the pin that it can act against.


Mine looks ecactly the same... so I am not sure it's the works of the altitude compensator. Perhaps it's factory made, it's where the altitude compensator is supposed to grab into ?

OK ... I will get those plastic bushings and see if that helps.
In case you need more on the Altitude Compensator.

With the truck at sea level and idling, the compensator tip must only rest ... on the fuel lever pin.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
User avatar
philip
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Posts: 1494
Joined: 15 years ago
Location: Southern California, USA

#14

Post by philip »

zoltan wrote:SNIP Now if I set the smoke screw so that the engine runs strong without smoke (or not as much smoke that I can detect in the rear view mirror), then the engine shuts down normally.
Then stop mucking with the setscrew. Inconsistant shut down is a matter of MOVING the fuel control lever far enough to kill the engine.

There are two points to inspect/adjust.

1) worn linkage rod pivot bushings
2) correct fuel lever overrun adjustment

There is a plastic bushing on each end of the link rod. Linear slop will diminish the IPC's ability to push/pull the fuel control lever considerably and thus ... starting and shutdown reliability.

This image shows the Fuel Control Lever in RUN ('drive'). AFTER you get new plastic bushings on the link rod AND with the engine idling, loosen the two adjustment screws and move the overrun plate so that the 'pin' is centered in the hole. The adjustment slots WILL be way off at one end as shown. Test. :wink:

Image
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
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Knucklehead
Posts: 148
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Location: Phoenix

#15

Post by Knucklehead »

DID ANYONE REPLACE THOSE BUSHINGS BEFORE?
When I first got my truck back in about '90 everything was worn out. All linkage ends and spindles were nearly worn through, bushings long gone. I built most things up with brazing rod, including both contact points for the altitude compensator. On one spindle on the pump linkage that I didn't want to do because I didn't want to discolor the zinc, I have always just used a 1/4" brass ferrule (which is slid over in the picture so the wear is visible). I have replaced most bushings a few times since. I usually use whatever is at hand or modify something from the hardware store. Quicker and cheaper than going to Nissan.

Image
Image
Last edited by Knucklehead 14 years ago, edited 1 time in total.
'82 standard cab 3 axle SD22 turbo
'89 int'l 9700 Cummins 444 (855 ci)
'29 HD FD export model
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