D-max up and running!!

Discuss (and cuss) the Nissan LD-series OHC Six diesel engine, popularly available in the US in 1981-83 Datsun/Nissan Maxima Sedans & Wagons.

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asavage
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#16

Post by asavage »

Allen wrench on the bright spool-shaped spindle (with the big spring on it). Loosen it and the other bolt, push tensioner against the spring.
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#17

Post by RacnJsn95 »

I ended up just taking off the tensioner all together, since I couldn't find anything in a search... So here's my next dilemma... I can't find a mark on the crank at all! There are 2 paint marks, one on the end of the crank shaft, and one on the timing cover (I guess the mechanic was lining them up?) but I don't see an indentation...

Also, what's the torque spec on the front crank bolt (27mm)? I accidently broke it loose while turning the engine over with a wrench.

*EDIT*
Here's what I have to go off of...

Image

I spun the crank around 3 times, and I can't find a mark... when I look at this picture here : http://img215.imageshack.us/my.php?imag ... rk2qd9.jpg, it kinda looks like the mark is on that "flange" behind the IP belt gear... When I turn the engine over, that "flange" on my motor does not move at all... It's about dark, so I guess I'm done for the night :(

*EDIT* Well I went out and felt around that flange, and I found the mark... But since that doesn't seem to be connected to the gear anymore, what can I do? That "flange" actually turns by hand now that I've actually gone out and messed with it...

So if you go back to the first post, by the PO, you can see it says the mechanic said he thought he had the timing wrong the first time because it was blowing white smoke! I bet the first time he had the IP, on the B mark, but was off on the crank shaft, since there is really no REAL mark to go off of.
82 Maxima Diesel, Auto 164k
77 620 k/c 4x4, 4spd, L20b (wishes it was an LD20)
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asavage
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#18

Post by asavage »

What you should be able to do is use the look-though-the-oil-filler-hole method to get to near TDC (on the correct stroke), then pull the plastic plug out of the bellhousing cover (about 1" dia., above the starter) and line up the real TDC mark.

At that point, I think the crank TDC/belt mark is straight up, and you should be able to ignore the flanged area not moving.

Crank bolt torque spec is 101-116 ft/lbs. Use loc-tite.
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asavage
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#19

Post by asavage »

That belt guide with the timing mark is keyed. Somebody may have shoved it onto the crank and then put the woodruff key in, in front of it, and just mashed the guide when putting on the crank sprocket.

I don't think I have a spare guide, but you might want to use your puller and remove the sprocket and look behind it. I pull it off whenever I have to replace the front crank seal, it's not hard, but does require a puller (ie you can't pry it off with a BF screwdriver).
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.
RacnJsn95
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#20

Post by RacnJsn95 »

Oh yeah, I forgot about that. I went out and cleaned all the grease off so I could see the marks. Where I have it sitting right now, lined up with the paint marks the mechanic made, it looks like it's about 1/8"-1/4" off from the marks on the flexplate, and trans cover plate. I'll line them up tomorrow, and hopefully you're right about the mark being straight up.
82 Maxima Diesel, Auto 164k
77 620 k/c 4x4, 4spd, L20b (wishes it was an LD20)
RacnJsn95
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#21

Post by RacnJsn95 »

Well it's running, but there is LOTS of white smoke. I guess I'll double check the timing, and see if maybe I got it off by a tooth. It's a pain in the ass to start cold. The glow plug light only stays on for 5 or less seconds, so my Dad says it much have some burnt out flow plugs?
82 Maxima Diesel, Auto 164k
77 620 k/c 4x4, 4spd, L20b (wishes it was an LD20)
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kassim503
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#22

Post by kassim503 »

I think the gp's only run for a couple of seconds when the key is turned to the on position, it turns itself off so it dosent heat up the gp's to the point where they burn out. Try cycling the key from acc to on 2-3 times before starting, letting the gp's run for like 15 seconds. The starting would probably get better, 5 seconds of gp time probably isnt enough for winter cold starts.
'83 maxima sedan, l24e, a/t, black

227K SOLD 6/7/2012
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asavage
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#23

Post by asavage »

Kassim: you don't know what you don't know.

Racn: Listen for the main GP relay to drop out. It's loud and sounds like it's behind the glovebox. Don't crank when the dash light goes out, wait for the clunk.

On the rigs I've had, most of the Maximas will not really give a second glow cycle by cycling the key.

Lots of white smoke sure sounds like too advanced. Stutters too?

Bear in mind that you do not need to reassemble the engine to test run it, as long as you don't run it very long (over a minute, for example). The LD28 is a lot of cold, cast iron. If you have the radiator out, with an AT you do have to run a loopback line on the AT cooler lines though.
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.
RacnJsn95
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#24

Post by RacnJsn95 »

Well the weather is finally good enough on my day off to work on the car again, without getting rained/snowed on.

I reset the timing, and quadruple+ checked it, and it's dead nuts on. As far as the glow plug relay goes, the first time it "clunks" as after about 5-6 seconds, which is generally when the dash light goes off, or shortly after, no more after that.

If I just try to start the car with no throttle it will fire and die... If I try to start it with Half throttle it will start and keep going, if I keep it going for about 20-30 seconds it will idle on it's own.

It sounds fine, runs fine, but blows the white smoke out still! I'm going to try to retard it back one tooth from where it "should" be, and see what happens. Aside from that all I can possibly think of is that it has a blown head gasket, or a bad IP pump....

When my Dad's 92 (N/A diesel) 7.3 ford's IP started taking a dump, it started blowing white smoke similar to this Maxima, and was really down on power... He talked to some diesel mechanics and they told him to change the IP... He put a new one on and it stopped smoking, and had all it's power and then some back!

What do you guys think?
82 Maxima Diesel, Auto 164k
77 620 k/c 4x4, 4spd, L20b (wishes it was an LD20)
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asavage
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#25

Post by asavage »

From the top . . .

My LD28s liked to glow about eight seconds exactly in most weather. It was almost never enough time for a truly smooth start.

The "Wait" light generally goes out a couple of seconds before that.

You are certain about the timing being right. Next most likely (on an LD28) would be an injector. It would not run smoothly though, but then again you've never heard this engine run smoothly so you do not have anything to compare with. To test, get it idling on its own at the lowest speed it will idle reliably (but no lower than normal). One at a time, loosen each injector line -- the larger, steel line from the IP to the injector. Loosen at the injector. Use two wrenches to prevent line damage. The idea is to let the fuel that would normally be squirted by the injector to just leak out instead. This is called "cracking the lines" or "cracking the injectors". At idle, and for the under ten seconds you will have the line loose, it does not amount to much fuel. The cylinder will fail to fire and will not contribute to keeping the crank turning.

What should happen when you loosen the line nut is that the engine should drop in speed and run very noticeably rougher. If it does that, tighten the nut and move on to the next injector.

When you find a "dead" cylinder, loosening the line nut will elict no (or very little) change in the way the engine is idling. That is the suspect injector to check or swap or have rebuilt first.

A single cylinder with low compression (burned valve, misadjusted valve, blown head gasket, worn cylinder/piston/rings) will give the same result on the above test.

Low compression or a bad injector are the most likely causes of white smoke if the injection timing is correct.

WRT your dad's 7.3l, that Stanadyne/RoosaMaster DB2 IP is a very different critter than the Kiki Diesel (Bosch licensed) VE-style IP. I do not recommend swapping or rebuilding the LD28's IP for a white smoke symptom. Rebuilding a DB2 is cheap, maybe one-fourth the cost of rebuilding the LD28's IP, and the DB2 is not noted for going a long time between rebuilds.

I can rent you a setup that lets you verify (somewhat) the IP timing without too much work, as long as your engine will idle. See the FAQ: IP Timing section for more info. You will need to supply your own timing light (std gasser tool). My tool has a pickup which clamps to the No. 1 injector line, and its output is a signal that your std. gasser timing light can read. You get the engine idling, connect all this stuff up, and shoot the TDC mark on the flex plate, through the hole under the rubber plug above the starter. There is only a TDC mark available. The tool I have lets you advance or delay the trigger signal for your timing light, so you can "line up" the TDC mark even though it's actually firing several degrees BTDC. Then you read the offset you dialed in to get to that point, and read the number of degrees advance on my tool.

On my rigs, 8° BTDC at idle is about right (so far: we do not yet know the exact correct figure). If you are off of that figure by more than a few degrees, you still have a timing problem.

But try the line crack test first. If cracking all six injectors gives all cylinders dropping idle speed correctly, you'll have to look harder at timing, and overall compression.

HTH
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.
Carimbo
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#26

Post by Carimbo »

RacnJsn95 wrote:I reset the timing, and quadruple+ checked it, and it's dead nuts on.
Curious to know: HOW did you set the timing? This is not an easy task, even w/ the specialized (difficult to procure) tools. Or are you talking about the gross IP-to-crank cogs count and pulley orientations relative to each other?
RacnJsn95
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#27

Post by RacnJsn95 »

When I say timing I mean the pulley orientation, and number of cogs on the belt.

From where I had it yesterday, I retarded one tooth on the IP pulley, as it was suggested the white smoke was a "too advanced" symptom. Maybe I had it off before both times? Now the car starts much easier (although I still have to keep it running for 10-15 seconds before it will idle on it's own), but still smokes while it's cold... If I let the engine build some heat (even though the gauge is still on the cold mark, or slightly above), it stops smoking. Seems to run fine, no stuttering, etc., and I drove it for the first time last night seemed to have good power for what is it, I actually expected less.

My Dad says it looks like it just needs to be driven and burn the crap out of it, and the exhaust system, and it will probably clean up from where it's at now...

How much do you rent your timing tool out for Al?
82 Maxima Diesel, Auto 164k
77 620 k/c 4x4, 4spd, L20b (wishes it was an LD20)
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asavage
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#28

Post by asavage »

There's not really any crap to "burn out", and after a couple of full-load run-ups, the running condition isn't going to change unless you change the fuel to something else. Carbon doesn't "burn", at least not at the temperatures available, and while I've had motor oil in an exhaust system take a long time to dissipate, that was a gasser with a holed piston that dumped a lot of oil into the catalytic converter. The only thing you should have in your exhaust system is fuel, which isn't going to remain in the exhaust very long.

====================================

The Kent-Moore Tach-N-Time J-33300 is available for use to established forum members for free. I own two of them (just as I have two compression testing setups), so I still have one available while one is on loan.

The borrower pays shipping both ways.

My concern is about loaning it and actually getting it back. I've had one "scare" already, so I'm getting so I'm not as comfortable loaning it as I used to be, and I've gotten screwed twice in the last year. Folks who have been here on the forum for a long time, I send off a unit pretty easily. Other folks who have dropped in and don't have history with us, I have to have a hefty deposit.

Basically, I now require a credit card number to loan it out. If it doesn't come back, I have to be able to replace it.

I will charge a modest amount to the card immediately to cover the outbound shipping -- this verifies that the card is active. If the unit doesn't make its way back to me in a reasonable period of time (like more than a month, for example, unless there is a good story involved), then I would charge the card to replace the $1200 Tach-N-Time -- based on the two I've purchased, I'd probably charge about $300 -- again, only if I don't get it back. They can be had for less than that, but not retail and not in a hurry.

(I have a $330 MT257 but have not tested it yet.)

If you have a modern gasser timing light that has built-in advance/retard controls, I have a Snap-On MT257 that only provides the trigger signal and does not do advance/delay of the inductive trigger signal. The MT257 is cheaper to ship because it's a much smaller unit.
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.
RacnJsn95
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Location: Central Point, OR
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#29

Post by RacnJsn95 »

Well at this time I'm not interested in renting any tools since you put it that way.

Upon checking out the car some more, I accidentally advanced the IP a tooth instead of retarding it. So I'm gonna go retard it back one tooth from where I've been setting it at where I presume is stock and see what happens.

Upon further inspection, the cold start thing vacuum line isn't hook up to anything (vacuum line with a white or yellow stripe), and also a line with a red/orange stripe on it that goes to the vacuum pump isn't hooked up... I'm gonna search for a vacuum diagram, but if someone could tell me where these lines are supposed to go?

I haven't "cracked the lines" yet, because it seems to be running fine on all cylinders, and I'm not really sure about the timing BS...
82 Maxima Diesel, Auto 164k
77 620 k/c 4x4, 4spd, L20b (wishes it was an LD20)
goglio704
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Joined: 18 years ago
Location: East Tennessee

#30

Post by goglio704 »

The Cold Start Device does not have any vacuum connections. It has coolant hoses and mechanical linkage. The only vacuum device on the IP would be the valve which modulates the vacuum signal to the transmission. It should have a connection to the vacuum pump and to the transmission's vacuum modulator. With a line disconnected, the transmission should be shifting hard and late.

Also, some white smoke while warming up is not unusual. If the car runs well and doesn't smoke once it is warmed up, I'd say the timing is acceptable.
Matt B.

83 Maxima Sedan, LD28, 5 speed, white, 130k miles. My original Maxima.
83 Maxima Sedan converted from gasser, LD28, 5 speed, 2 tone blue, 230k miles
82 Maxima Sedan, LD28, 3 speed auto, 2 tone Gray/Silver, 140k miles
81 810 Sedan, LD28, 3 speed auto, rust, rust, and more rust!

2005 Jeep Liberty CRD
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