* SD22 FUEL INJECTOR NOZZLE EXPERIENCE *

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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philip
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* SD22 FUEL INJECTOR NOZZLE EXPERIENCE *

#1

Post by philip » 14 years ago

I took a quick trip to Phoenix, AZ and back. 780 miles round trip in 24 hrs.

On the return leg, it became very evident that the injectors needed to come out for servicing.
They've NEVER been serviced in 155k miles. At one stop, one cylinder began dead misfiring
at idle. Gunned the throttle twice ... it cleared up. Also, on the grade before Quartzite and
the short grade after Blythe, I witnessed a couple of HUGE momemtary puffs of black smoke
at full throttle.

So today out came the injectors. Took them to an authorized Stanadyne/Zexel diesel shop
in Anaheim for rebuilding. On request, the shop owner bench tested them for me. NONE had
a decent spray pattern, #2 had a 'Y' spray pattern and #4 had a straight stream. Also, #2 had
much more fuel bypassed after discharge than the others. Pop-off pressures were all in the
1600 psi +/- 50 range.

In spite of these findings, the truck gave 35.5 mpg going and 36.4 on the return leg! Amazing.

Estimate 2-3 days for rebuild work.

Removing the injectors from the cylinder head was easy enough. BUT ... digging out the
copper crush washer at the bottom the the bore was a Pain in the Tusch!! After torquing,
the soft washer locks it's OD to the bore wall as well as deforming to the bore floor.
Furthermore, the washer's ID is the same as the opening into the prechamber. An
EZ out didn't work but an ice pick with the tip bent 90 degrees did. Again ... PIA !!!

Image

Note: This is an '82 SD22. It has flat crush washers under the injectors. Now, the SD23 and SD25 shown
in the sketch have a "formed" crush washer. Hmmm! :?

I'll follow up with costs and results after everything is back together.

-Philip

Image

Tools needed to remove the injectors from the engine:
17mm for the high pressure delivery line nut.
22mm for the metal overflow/return line set.
27mm (1-1/16") DEEP socket for the injector itself.

24mm to disassemble nozzle holder from injector nut (housing)

Image

Image
The SD25 uses this stamped design.

Image
The SD22 calls for the solid copper sealing washer but I do not see why the SD25 style crush washer could not be substituted. Washer OD dimension: 0.54" to 0.6" (13.7-14.8mm)

Image
When you get a "rebuild", the nozzle body and the HIGHLY precision fitted pintle valve inside are replaced with these NEW assemblies. But do not include the middle washer shown here to seal the nozzle nuts.
Last edited by philip 13 years ago, edited 13 times in total.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

glenlloyd
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#2

Post by glenlloyd » 14 years ago

I have always wondered why manufacturers use different types of seal washers in their applications when the injectors (or holders) are of the same type. Peugeot uses a copper crush washer, as does Nissan, but VW uses a steel washer with a cone shape and a very small opening. The cone edge sits against the nozzle and I think reduces the area where the nozzle becomes dished.

Peugeot is similar to Nissan with the problem of extracting the copper washer, but with VW they come out pretty easily. I have thought about using the VW washers in other applications but haven't yet. I may try this in the Peugeot when I locate a new motor.

Good points, injector maintenance is often overlooked on diesels, but the $100 or so it costs me to have the injectors cleaned, checked and adjusted I've found to be worth it. That doesn't include new nozzles however, which adds a lot sometimes, especially for the Peugeot 2.5 TD. I'd like to be able to do the work myself but don't have the tools for the job. I don't usually like to farm-out work but with injectors I've had to in the past.

steve a
97 Jetta TDI, 86 VW Golf D
89 VW Fox diesel, 92 MB 300SD W140

gir - won't the sploding hurt?
zim - silence!

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philip
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#3

Post by philip » 14 years ago

glenlloyd wrote:I have always wondered why manufacturers use different types of seal washers in their applications when the injectors (or holders) are of the same type.
On this point, a thought has occured to me. Feedback from field warranty work may have found an unnecessary expenditure of time spent on digging out the flat copper copper washers so ... in the interest of not paying more than absolutely necessary (I spent a good 30 minutes digging these four buggers out of their bores), the factory changed washers to something less determined to weld itself to the cylinder head.

snip
Good points, injector maintenance is often overlooked on diesels, but the $100 or so it costs me to have the injectors cleaned, checked and adjusted I've found to be worth it.
snip
steve a
For the four injectors I paid $210 to have new nozzle assemblies installed including shop labor. I pulled the injectors out and delivered them. The way I see it with these injectors, cleaning them is a waste of time because new nozzle assemblies are only $20-$25 each + labor. At that price, cleaning them is like pulling spark plugs, filing the electrode square again, sand blasting them, and reinstalling. Not at all cost effective.

Fuel Injector Rebuilder

DSI Diesel Specialists, inc
Authorized Bosch, Stanadyne, CAV
Nippondenso, Roosa Master

Edgar Sibiglia
350 E. Orangethorpe Ave. #12
Placentia, CA 92870
9714) 528 8442

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Last edited by philip 14 years ago, edited 3 times in total.
-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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philip
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#4

Post by philip » 14 years ago

Follow up.

I installed the re-nozzled injectors. Intersting things discovered when I took some closeup pictures of the pintle valve tips. For all the fuel injector cleaner and B20 I've run in the past 10k miles, it didn't do squat at the most important point ... the pintle valve and nozzle.

Right away, the engine ran different. More responsive, better torque in lower gears, and sootier exhaust. Hmmm. The exhaust smoke thing was fairly visible in the side view mirror. So I removed the altitude compensator and fiddled with the smoke screw adjustment screw while charging up some hills until satisfied with the smoke output. Reinstalled and readjusted the compensator linkage. BTW, gaining access to the smoke screw is facilitated by using a shorter oil filter. I've been using a Wix 91068.

Last night was the first opportunity to check fuel mileage on a trip to Oceanside and back. 105 miles consumed 2.6 gallons (60 mph cruise on I-5). Considering the coolish ambient temperature, that's a 4 mpg increase!

The first image is with a cleaned up pintle valve. The second is typical of all four.

Image Image
Last edited by philip 14 years ago, edited 3 times in total.
-Philip
Passed 08May2008
My friend, you are missed . . .

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

TheDieseliminator
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#5

Post by TheDieseliminator » 14 years ago

Philip, I thought you said after you get your injectors rebuilt and installed you wouldn't see a fair amount of increase in your fuel mileage. That's what I said look to see happen after you test drive the truck with the newly rebuilt injectors on the Nissan/Datsun 720 diesel board. Not sure if you remember, but I guess I was right about you getting a good increase in fuel mileage. I'm not boasting, but I just wanted to see if you'd remember or not. :wink: Otherwise, I'm glad to see you're getting that much increase in fuel mileage after your first test drive and you gotta love that. Hope the efficiency lasts for another 155k miles.

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philip
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#6

Post by philip » 14 years ago

TheDieseliminator wrote:Philip, I thought you said after you get your injectors rebuilt and installed you wouldn't see a fair amount of increase in your fuel mileage. That's what I said look to see happen after you test drive the truck with the newly rebuilt injectors on the Nissan/Datsun 720 diesel board. Not sure if you remember, but I guess I was right about you getting a good increase in fuel mileage. I'm not boasting, but I just wanted to see if you'd remember or not. :wink: Otherwise, I'm glad to see you're getting that much increase in fuel mileage after your first test drive and you gotta love that. Hope the efficiency lasts for another 155k miles.
I said that I did not EXPECT much and then quoted "Unfulfilled expectations are the seeds of depression."

After installing the rebuilt injectors, the first MPG test would have been LOWER fuel mileage. Exhaust smoke was visible on every significant nudge on the throttle and continuously when accelerating. Obviously over rich. That necessitated snipping the security wire on the smoke screw and monkeying with the adjustment to get the new situation corrected. Took about 1 to 1-1/4 turns clockwise to correct. That's significant. I set the smoke level were the exhaust could not be seen at all at 38 mph in 3rd gear at full throttle. We have several grades around here for testing. :wink: With this new setting, the truck still hits the engine speed governor in 5th gear (83 mph indicated).
-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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philip
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#7

Post by philip » 14 years ago

After installing the rebuilt injectors, the first MPG test would have been LOWER fuel mileage. Exhaust smoke was visible on every significant nudge on the throttle and continuously when accelerating. Obviously over rich. That necessitated snipping the security wire on the smoke screw and monkeying with the adjustment to get the new situation corrected. Took about 1 to 1-1/4 turns clockwise to correct. That's significant. I set the smoke level were the exhaust could not be seen at all at 38 mph in 3rd gear at full throttle. We have several grades around here for testing. :wink: With this new setting, the truck still hits the engine speed governor in 5th gear (83 mph indicated).
Update: I've got 3,000 miles on the newly rebuilt injectors. At the time, I also changed the engine oil and filter (NAPA 15w-40) and reset (leaner) the smoke set screw on the Injection Pump sufficient to stop all visible smoke on heavy acceleration.

With these changes, the engine has been consuming quite a bit LESS engine oil. It's down 1/2 quart in 3,000 miles. Typical consumption would have been 1 qt by 2,500 miles using Shell Rotella 15w-40.

The previous owner and I have performed oil changes in the 2,500-3,000 mile range. But the oil analysis on the last oil suggested I was changing the oil way too soon. Hmmm.

How/why did new injectors and different oil make so much difference?
-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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philip
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#8

Post by philip » 14 years ago

mikej678 wrote:Where do you guys get injector crush gaskets from? The Nissan dealer here isn't very helpful.
My friendly local independent diesel shop. I do not recall the OD/IN dimensions but I think they came from some GM application. These copper washers DID need their OD reduced about 0.015" so that they would fit into the bore.

The tip washer should be:
OD: 0.54"
ID: 0.27"
Thickness: 0.040"

Use ONLY the injector tip sealing washer.

If you are given this :shock: larger washer as the sealing gasket, the injector nozzle will not seal correctly or transfer heat from the tip correctly, resulting in damage and tip coking.

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

1982 Datsun 720KC SD-22

"Im slow and I'm ahead of you"

moose60
Posts:168
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#9

Post by moose60 » 14 years ago

I recently (Aug 2006) had my injectors rebuilt at H and H Diesel in Milton, WA for $230 including tax. They were able to do the work in about two and a half days. They will give you SD25 style crush washers for the injector tip, but can supply the SD22 style flat copper ones, if you ask.

The rebuild cured 95% of my cold start smoke show and rough running problems.

Fuel Injector Rebuilder

H&H Diesel
407 Porter Way
Milton, WA 98354
(253) 838 3030

Milton is about 5-6 miles east of Tacoma.
Byron

82 Datsun 720 KC SD22

MPG Machine

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asavage
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#10

Post by asavage » 13 years ago

I'm working with my "Orting Truck" today.

In this illustration:
Image

The metal return line (ref. 16670N) is fastened to the injectors with the 22mm hex nut (ref. 16627M). Between the nut and the rail is shown a copper washer (ref. 16627C).

My return rail has been off, at least a couple of times. When I took mine off, those washers were between the rail and the injector nozzle holder (ref. 16611M), and looking at the parts, that looks correct. But the parts illustration shows the washer above the rail, where sealing doesn't need to occur. I surmise this exploded view is incorrect.

Can someone verify where their washers are?
Regards,
Al S.

1982 Maxima diesel wagon, 2nd & 4th owner, 165k miles, rusty & burgundy/grey. Purchased 1996, SOLD 16Feb10
1983 Maxima diesel wagon, 199k miles, rusty, light yellow/light brown. SOLD 14Jul07
1981 720 SD22 (scrapped 04Sep07)
1983 Sentra CD17, 255k, bought 06Jul08, gave it away 22Jun10.

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philip
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#11

Post by philip » 13 years ago

This is the way my engine came in and that's how I put it back. I seem to recall there was some kind of thing o-ring or crush into the top flat nut. But I'm not certain. There is a reason for those washers having 4 holes. It permits DRIBBLE fuel to pass from the injector to the line exiting.

There is green paint on that line except where flecked off next to the flat nut. The copper washer is pretty clear. Right or wrong, you can see this way does not leak. :)

Image

Also ... that 16635 is NOT correct. Scroll back up to see what happens when you do use it. The tip is the only correct washer and location.
-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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#12

Post by Zoltan » 13 years ago

Great picture with the mirror! Took me a second to notice...
- Zoltan -
________________________________
'82 Datsun 720 SD22 California model
'86 Ford Escort 2.0L Diesel

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philip
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#13

Post by philip » 13 years ago

Zoltan wrote:Great picture with the mirror! Took me a second to notice...
Hahhaa. At the time of doing this little creative artistry, a twin injection system occured. One for Indirection ... one for Direction. But why? :wink:
-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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asavage
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#14

Post by asavage » 13 years ago

That's just a little too subtle for me, Philip . . . can you expand on that?

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philip
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#15

Post by philip » 13 years ago

A little less left brain, a little more right brain than before. Subtle reconsiderations when I see things now. This is an example. :wink:
-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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