rd28 diesel n/asp.

[jean]

Hello all you Boffins!!
Seriously hope to get a remedy for my RD problem and extreme head-ache. Have a RD28. had the head + valves done(2X). New injectors + pump redone. Set cam + crank (Bdc) marks. However, pump mark (on sprocket) does never ever line up with mark on block. Always either half tooth over or below. Now for the last 3 mnths I am struggling to make this "monster" run properly/evenly. Had all injectors re-checked, pump rechecked etc. Timing ok. But.... On start-up, when cold, engine runs very rough, like on 5 cyls.' and lotta blue smoke. When revving to some 1500 rpm, motor starts running evenly and blue disappears. When motor has warmed-up, motor runs ok except does not go past 105km/hr. Also, slightest uphill and motor wants to "go into reverse" drops to 75-80 kms. I am just about to give the monster a shot of cyanide.. No-one here in South Africa even has details, let alone, knowledge of RD28 diesels. Is a wholly import here. PLEASE anyone with some info. Highy appreciated. JJ

[leadpaw]

sounds like your injection pump timing could be off.

[jean]

Hi, Leadpaw. I have tried all the variations possible with the belt and pump-timing mark. Absolutely no joy here. Just taken the monster out again. Lotta blue smoke untill motor has warmed up ( some 60 secs later). Then the horror runs smooth and fast (105kms) on the straight. The slightest uphill (even ever so slight), and it drops down to some 90-80 kms/hr. JJ

[rlaggren]

I'm afraid I'm not an expert, but there are many smart people here; I'll mention a few easy/obvious things.

Did the motor ever run OK? (helps to keep the faith up...)

Somewhere there is something Not Right here, so all the check points need to be checked again, paying especial attention to things you assume because they have to be fine, couldn't be any other way... It might be good to pay an pro to bench test the IP and check the hardware settings like cam timing, belt timing, pump timing, valve lash; IOW, get a (worthwhile) 2nd opinion vs, the previous checking you (and others) have already done. People can get in a rut and see and do the same thing over and over w/out ever actually seeing what they're doing, if you know what I mean. With the engine hardware vouched for you have fewer pieces of the puzzle to juggle.

Here's some other possibilities at random:
Is this a turbo? Does it work? Either NA or turbo, is the the exhaust flow clear (how do you know)? Intake clear (ditto)? IP linkages set up right? Done a compression test (probably not too bad if it starts)?

Something is slightly cocked with startup but maybe that's a separate problem... Or not. GP system needs checking of course, and maybe the starting problem relates to fuel not remaining in the lines.

Fuel restriction from the tank (if you have the Bosch V type this might affect IP advance)?

Does it smoke good on acceleration (hills)? Coolant temps OK? Coolant still there ? <g>

That's about it for my .02.


Best luck. Rufus

[davehoos]

from memory its a rd28T in a patrol?or a rd28 laurel?
not electronic controlled pump.

ignition timing at idle is 8 deg btdc.

mechanical VE pump on early types of often have a linkage to adjust the timing on start up.the american LD28[like the laurel] its water temp controlled but on a patrol its operated with a cold start cable,these are often not conected unless you live in snow covered areas.
ive seen le timing ring inside siezed but as the pumps been checked this would have easy to spot.also fuel delivery pressure.timing will retard if fuel supply is restricted.

my rd28 has a small lever on the side of the top,its adjustable.
its purpose is to set the injection amount at startup[not idle].i found it does more.IE it adjusts the fuel when cranking even if you have the throttle full open.

at work we have a ford transit for deliveries.been a long term project.
when we got it it blew a turbo---big clouds of smoke and no boost--exhaust full of oil.
a head bolt had junk in the bottom of the thread and gasses pushed into the oil supply passage for the turbo.this fixed it now runs ok.

recently the timing belt tension bearing died.it has a electronic injector pump.since i replaced it its lost power at 80+kmh.with 2 people on the hyway it needed full throttle prod to get it going and you have to work through gears.
when idling its allways hunted and surged,but now-when the a/c cuts in its runs rough.also has ignition bark when starting.

if the tensioner adjusted the timing i guess that it advanced it.

[jean]

Lo Dave. The RD28 in question was fitted inside a 110 landrover.As mentioned, pump has been overhauled. Crank set to +- 8 Degrees BDC. ( key facing down) Cam set on its pointer. Pump will only go either half tooth before or after mark. Have no other levers etc. on pump. Too hot here in South Africa. Water-heating disconnected. Just started up again. Plenty blue smoke, rough running untill revved-up or motor warm. Then running smooth. When I move crank 1 tooth AFTER bdc, keep cam + pump on their marks, Motor seems to run smoother. However noisy. I suspect piston to valve contact?. Is it perhaps possible that the piston-heads have to be "skimmed/cut"? because head was skimmed (is always done to isuzu engines) and only standard gasket is available here ( ex Laurel). Alternatively what about having a copper gasket made with greater thickness?. Am only thinking aloud. Perhaps you can advise?. Once again to inform you, that there is absolutely NO-One here who can help me with an RD28. (incl. Nissan agents!)Tks. Jean

[davehoos]

timing marks on the belt/cogs is for bdc.this is to allow the cam to be turned without touching the pistons.factory belt has a line on the belt X teeth apart.cam to ip is 25 teeth.crank to cam is 51.this is how yow fit the belt.

my timing belt had the marks on the belt and its rare for these to line up with the marks on the engine.

you can measure the valve lift to find the right possition for the cam shaft.
dont go moving the cam timing compared to the crank, it will kiss the pistons.

the pump can be moved to gain the best running possition-also fuel mixtures can be adjusted using small amounts-the factory settings are just a starting point.

valve clearance with pistons is adjusted by setting the valve seats.
there is no measure in the manual as my head reconditioner had to guess when i replace hydrolic lifters.top of piston is measured compared to valve possition and head gasket thickness is selected--mostly only the thickest is available and often shims are used.

injection timing of no 1 cyl is 8 deg bTdc at idle[or engine stopped]
you remove non return valve from the no1 injector pump and spill time the engine.the factory way is to messure the pump stroke.
special diesel electronic timing light can pick up the pulse in the injector pipe.
the water heated valve on the side of the pump adjusts the timing for cold start.it has to be adjust or removed for the normal advance to work.

the engine barks a little when cold-its an alloy head indirect injection engine.
water temp is important.thermostat is in the bottom rad hose and lets cold water in when the block gets to 82 cel.water in the top of the engine will be much much hotter.

[rlaggren]

Jean

re > loss of power

I just remembered that the LD28 can have intake manifold problems where it gets filled up w/grunge. Search "grunge" on this forum for the story. That could be restricting your intake air which would prevent you from getting much power out of the engine.

Rufus