Head-Bangin' SD22 DEAD CYLINDER WOES

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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Cmdr. Ron
Posts: 23
Joined: 10 years ago
Location: Middleburg, Fla., U.S. of A.

Head-Bangin' SD22 DEAD CYLINDER WOES

#1

Post by Cmdr. Ron »

Greetings & HE-E-E-ELP!

Short & not so sweet: New injctrs, rings, etc. 141,xxx miles. BLACK SMOKE so I replaced hole-riddled Leather Diaphram of infamy just as you guys showed me - else I'dstill be wondering.
Now WHITISH SMOKE - #3 & #2 NOT FIRING!
#3 gets fuel.
Not sure #2 gets any fuel.
Swapped Injctrs to see...no change.
Left out DELICATE Spill Tube...slightly snappier pedal response, but all else same.

NEED t o SEE Supplement Pages covering this, IF it does.
You guys got ANYTHING on this?
Greatful for ANY & ALL HELP.[/u]
'82 DATSUN 720 SD22, '77 Fiat 124 Spider, '81 Toyota HiLux, '64 Chevy Corvair Monza
The Blessing of Abraham is mine!
Nissan_Ranger
Posts: 267
Joined: 14 years ago
Location: Canada

#2

Post by Nissan_Ranger »

First things first; check the injector pump for proper functioning at idle.

You can check any injector circuit for fuel by loosening the injector fuel line (the high pressure line!) for that circuit while the engine idles, one circuit at a time. Good injection pressure would be evidenced by rhythmic pulses of fuel leaking from the fitting that is thus loosened. A properly functioning pump will have the same amount of fuel leaking from each fitting as it is loosened and in a properly functioning engine causes the engine to stumble while the affected cylinder is not getting fuel.

If the pump is functioning properly, then it is time to check the compression.

Keep us posted

N_R
The old 'six gun' was as popular as the cell phone in its time and just as annoying when it went off in the Theater.
Cmdr. Ron
Posts: 23
Joined: 10 years ago
Location: Middleburg, Fla., U.S. of A.

#3

Post by Cmdr. Ron »

OK . . . Here's the Skinny:

Insufficient flow on Cyl #3
Mere trickle on Cyl #2

Must open pump. Have no pix, instruction, precautions.
Only have '82 FSM.

Pump output side appears clean.

GOT PIX?
GRATEFUL for Experience shared.
Thanks,
Ron
'82 DATSUN 720 SD22, '77 Fiat 124 Spider, '81 Toyota HiLux, '64 Chevy Corvair Monza
The Blessing of Abraham is mine!
rlaggren
Posts: 541
Joined: 14 years ago
Location: San Francisco

#4

Post by rlaggren »

A French guy (I think) on a VW forum did a tear down in photos of a similar IP. I think it's referenced here somewhere but don't recall where. Somebody?

But that's just to cover the bases. I doubt seriously whether you want/can do that sort of thing. The whiz with the pics _was_ a whiz and at that he took a few short cuts IIRC. IOW, your mileage _will_ vary.

If indeed something inside your IP is bonkers, you need to think very seriously about how much it's worth to risk screwing the pooch, totally. And balance that against the going rate for a diagnosis and then a possible rebuild. I'm sure it's possible to rebuild one of the things on a home bench and if I didn't have anything else to do for a month or so and a few hundred for parts and tools I might even be willing to try it. But not if I didn't have another IP to put in the vehicle.

I'd try real hard to find the problem _outside_ of the IP before I thought about problems inside it. You might want to set things down, walk away from the problem for a week, then come back and re-think and re-do everything very slowly, carefully and thoughtfully, crossing all "i's" and dotting all "t's" <g> to make sure you have no choices left before you consider the inside of the IP.

Best luck. Rufus
82 Maxima wagon
Cmdr. Ron
Posts: 23
Joined: 10 years ago
Location: Middleburg, Fla., U.S. of A.

#5

Post by Cmdr. Ron »

:roll: THANKS for suggestions.
Daily Driver, Out of cash...must fix this problem
Anyone have spare IP?

Found manual in my library that covers these - near complete rebuild how-to! It has NO Diagnostics, just how-to. 5 or 6 pricey special tools not in my box.
A pal who went thru diesel school & worked it awhile says more likely injctrs. - no guarantee the new ones (2,500 miles) are OK. Swap & see.

Navy MM trained on some pumps +
1 yr diesel apprentice = DANGER, Will Robinson!

It's always easier to burn, break, or blow-up things when ya don't know what you're doing.
'82 DATSUN 720 SD22, '77 Fiat 124 Spider, '81 Toyota HiLux, '64 Chevy Corvair Monza
The Blessing of Abraham is mine!
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asavage
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Re: Head-Bangin' SD22 DEAD CYLINDER WOES

#6

Post by asavage »

Cmdr. Ron wrote:New injctrs, rings, etc. 141,xxx miles. BLACK SMOKE so I replaced hole-riddled Leather Diaphram of infamy just as you guys showed me - else I'dstill be wondering.
Now WHITISH SMOKE - #3 & #2 NOT FIRING!
Rings? You had the pistons out?

I'd do a compression check first.

The Inline style IP is nearly bulletproof (other than the leather pneumatic governor diaphragm, and the primer pump).
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.
Cmdr. Ron
Posts: 23
Joined: 10 years ago
Location: Middleburg, Fla., U.S. of A.

Still Broken

#7

Post by Cmdr. Ron »

GREETINGS!

THANKS for the input. :lol: . . . Could I have some more, please?
(PC calamity delayed this. . . Al ain't the only one with computer hairballs.)

This has STRANDED me WAY 2 LONG! :evil:

Oh, Yes sir, Al, I did have the pistons out. Soaked 'em in Carb cleaner & PB Blaster. Dry Graphite coated the skirts & ringlands & Rod Bearings.
- Couldn't figger it out, so I got everything but Liners for an INFRAME.
- Had a broken OIL RING.
- Had 5 or 6 "frozen" rings (All 3 on #4)
- Much hard, coked gunk
- Exhaust Manifold nearly blocked by soot build-up
- Roughness occurred SUDDENLY while at a stop light
- Instant lack o power evident when pulling away from same light
:?:
Still Only 2 cylinders firing, yet I have OVER-FUELING situation.
- Does CHANGING the Gov'nor DIAPHRAGM require adjusting the SMOKE SCREW?
- Would backing down Smoke Screw reduce OVER-FUELING?
- Why does the AmounT of FUEL TO INJECTORS vary so much? (a drip on #2, #3 trickles)
'82 DATSUN 720 SD22, '77 Fiat 124 Spider, '81 Toyota HiLux, '64 Chevy Corvair Monza
The Blessing of Abraham is mine!
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