Dealing with all subsystems specific to the diesel powered Datsun-Nissan 720 pickup trucks.

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plenzen
Posts: 891
Joined: 16 years ago
Location: Cochrane Alberta Canada

#1

Post by plenzen »

Ouch!
Odd Ball?
A 1987 D21 Nissan KC with an SD25 diesel engine, dual batteries, LSV for the rear brakes, 14 inch wheels, dual piston calipers, and multi sealed fuel injector’s (two gaskets I might add, not just one) yada, yada, yada, is NOT AN ODD BALL!!.
It's at best,,,,, perhaps an anomaly!!

Political correctness you know!! Not quite as harsh!!

Paul
Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
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philip
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Location: Southern California, USA

#2

Post by philip »

plenzen wrote:SNIP- ... and multi sealed fuel injector’s (two gaskets I might add, not just one) ... -SNIP- Paul
These injectors are not to have TWO gaskets. If you do ... there is danger of not sealing TIGHT the nozzel face to the cylinder head. In spite of what you find as replacement part, ONLY the nozzel gasket should be installed.

Doubled gasket horror

You will find that entire thread interesting.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
plenzen
Posts: 891
Joined: 16 years ago
Location: Cochrane Alberta Canada

#3

Post by plenzen »

Even if the FSM says to use both? I had them rebuilt and installed them with the two gaskets like it said and pulled them to the required torque of 51Lbs. I was not aware that there were issues in this matter? Should I remove them again and get new tip washers and reinstall without the copper ones?

Paul
Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
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philip
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Location: Southern California, USA

#4

Post by philip »

plenzen wrote:Even if the FSM says to use both? I had them rebuilt and installed them with the two gaskets like it said and pulled them to the required torque of 51Lbs. I was not aware that there were issues in this matter? Should I remove them again and get new tip washers and reinstall without the copper ones?

Paul
The FSMs does NOT show two gaskets (nozzle and nozzle nut secured to cylinder head) ... nor did I find in my ORIGINAL "nozzle nut" on my 1982 SD22.
Image

Please revisit *Injector Nozzle* thread

Do notice that the 'Zexel' replacement parts are used for many applications. In this case, the middle gasket (of three) is not used in this SDxx application.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
plenzen
Posts: 891
Joined: 16 years ago
Location: Cochrane Alberta Canada

#5

Post by plenzen »

I scanned the picture from the FSM and will post it with this. Pretty sure that is shows 2 gaskets, although I could be wrong

Paul

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Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
exsimguy1
Posts: 27
Joined: 17 years ago

#6

Post by exsimguy1 »

My SD25 (an 83 US model engine) had both gaskets as delivered from Nissan (mine had never been removed). Upon re-nozzling, the supplied replacements (upper washers) were too thick to properly crush the SS "dimple washers" at the tip. Somewhere there must be dimensions available to account for the tolerance stacking that happens when nozzles are replaced. It would be better to have both sealing washers in place with the proper crush. The alternative is to use just the nozzle seal (copper or SS "dimple washer") and torque to spec. It does work.
Terry
1987 D21 w/1983 SD25 drivetrain
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philip
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#7

Post by philip »

"exsimguy1" ... thank you VERY much for that personal information. :)

My '82 had the nozzle solid copper washers ... no nozzle nut gasket included at all.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
exsimguy1
Posts: 27
Joined: 17 years ago

#8

Post by exsimguy1 »

Phillip,
I think the upper (larger) sealing washers would tend to keep contaminants (such as water) from leaching down past the threads and settling on or around the nozzle. This "stuff" tends to fall into the hole upon removal. With the upper washers in place, my usual high pressure air application to dislodge anything around the injector usually limits any intrusion of "stuff" into the combustion chamber (pre-chamber actually).

Terry
1987 D21 w/1983 SD25 drivetrain
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philip
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#9

Post by philip »

exsimguy1 wrote:Phillip,
I think the upper (larger) sealing washers would tend to keep contaminants (such as water).... -SNIP-
Terry
Well then ... a hard rubber or nylon washer would be sufficient and could not affect the smaller nozzle gasket thickness.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"
plenzen
Posts: 891
Joined: 16 years ago
Location: Cochrane Alberta Canada

#10

Post by plenzen »

"Upon re-nozzling, the supplied replacements (upper washers) were too thick to properly crush the SS "dimple washers" at the tip. Somewhere there must be dimensions available to account for the tolerance stacking that happens when nozzles are replaced. It would be better to have both sealing washers in place with the proper crush. Terry
I have a set of Nissan copper "Nut Gaskets" here and they are .061 - .062 thick each. They are used however, but were the ones in there when I re-tipped a couple of years ago

Paul
Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
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