Killermiller

After fixing the air/fuel mixture problem by swapping the whole throttle body that was off the old engine (vacuum was ok, injectors, maf and tps too... perhaps there was some dirt clogging some duct or some vacuum valve sticking closed or open, I don't know), I performed a compression test. Values 1 to 4 cylinders are 155 - 150 - 150 - 155 psi with COLD engine (specs are 131 min and 173 max with HOT engine, so I should be on the high side); squirting some oil inside the chambers made me gain an additional 20ish psi per cylinder. I think this is ok for a 30 y. o. junkyard engine. The engine pulls strong and sounds good; only when going on LPG is not perfect yet (as said elsewhere, this car has an additional LPG fuel system fitted by the previous owner, with a 58lt LPG additional tank). Having zero experience with LPG fuel systems, I still haven't figured out what's the problem, but it shouldn't be anything major, Also, a new window regulator has been installed (being the steel wire of old one messed up) ... and a new rear window switch

If you're talking about the injectors harness, I would suggest to buy some standard automotive waterproof connectors, cut off what's left of the old connectors/wiring, and rewire the throttle body using the new connectors. If you lost the ones that go into the MAF sensor or the TP sensor, instead, I would use some fastom connectors. Little more tricky and needs to be waterproofed someway afterwards, but better than nothing.

Yes, three times a 55 code. I've finally bitten the bullet and swapped the entire throttle body, including sensors, injectors and everything, with the one taken from the old engine. This solved the problem but also leaves some questions unanswered, which I don't like, but hey... Now the engine runs smooth and fine, without missing a beat. I had to enrich a little on LPG, though. I will go on with the restoration during this summer and will put it back on the road in autumn; by then, I will be able to perform a good and long test drive. About what happened to the last engine, here is the (horror) story:

Absolutely no difference with the O2 sensor unplugged. Also, I did perform a self-diagnosis and 1) apparently no codes are stored in the ECU, and 2) no codes are thrown during real-time self diagnosis (mode 5); I did not drive the car, but I was struggling to avoit stalling by depressing continuously on the gas, so I guess this should be enough for the ecu to detect a malfunction. This puzzles me, but also MIGHT indicate a vacuum leak too, since in such case everything should look fine to the ECU, only the ECU itself is unable to correctly provide the right amount of gasoline needed for a correct stoichiometric ratio. I didn't look at the spark plugs, but, judging by the exhaust smell, it seems running rich to me. I've seen on the manual and there is that valve inside the throttle body, a V.C.V. valve (vacuum control valve?) that might be worth taking a look at. In the meanwhile thank you, I'll keep you updated.

Hi to everybody, my newly installed Z24i has some fuel-related issue. It hardly starts, stalls immediately at idle, stalls when keeping the gas pedal depressed. The only way to keep it running, is to bleep on the gas continuously, and, even doing so, it is impossible to go past 2000 rpm. When in limp mode, runs apparently fine (except for the 2.800 rpm limiter, of course) and idles well. This should narrow a little the possible causes list, because at least TP sensor, injectors and almost everything ignition-related should work fine (otherwise it won't run on limp mode neither, I believe). I've replaced the MAF sensor with a known-good one with no difference in behaviour. I've looked for some vacuum leak letting some unmetered air into the manifold, but didn't find any. I suspect a bad O2 sensor, although it shouldn't give such a drastic symptom (the car is absolutely undriveable). The car has an LPG system installed by one of the previous owners, and it exhibits the same problem when running on LPG, except that it will run fine if I clog the intake duct with a rag (hence my vacuum leak theory). Nonetheless, the rag trick won't work when switching to gasoline. I didn't perform an ECU self diagnosis, yet (which will do perhaps tomorrow). In the meanwhile, any input would be greatly appreciated.

Thanks, jjonez. . Today I started the engine for the first time. Has some issues I believe due to something injection/related* and/or some vacuum hose disconnected, but otherwise sounds pretty good. *The Z24, unlike KA24 and the VG30, has a single-point injector. As far as I've figured out, it doesn't have a fuel rail, but sprays fuel inside the intake manifold from above, acting more like a carburetor. It sat for years, so it might need to run a little to clear up.

Yes! Just like Mary Poppins' oil pan! By the way, why double tightening torque on the manual? Is that a minimum and a maximum? Also, is it mandatory to replace the six flywheel studs or can I reuse them, perhaps using some thread lock just to be on the safe side?

Differential down. Manual says to drop the diff with the crossmember still attached. Didn't work for me. I've spent almost an hour sweating and cursing under the car, till I've finally decided to remove those three studs securing the diff carrier to the crossmember. Two minutes to remove the studs, 10 seconds to drop the crossmember, 10 seconds more to drop the differential. A couple of bellhousing upper studs a little tricky to get at... ... and off it came with no particular hassle. This is the inside of the oil pan: The grayish slime is mostly iron dust. You can see, on the right, one of the pieces of the timing guide. The rectangular thing is a magnet I've previously dropped inside the pan in an as desperate as unuseful attempt to limit the damage. I have no idea about the round thing that looks like a broken washer. I will investigate this, just for the record. More and more amazed by the fact that, in spite of the knock, the missing tensioner, that mysterious washer and all this ferrous debris in its guts, this engine was still going without burning any oil. ... and voila - that's the reason for the knock: #1 rod bearing spun and broken. This is the crankshaft... ... and that one on the background is the rod. Maybe can be reground, maybe not, but - since I went to the route of an engine swap - I think is pointless for now. Perhaps, if not beyond repair, I will keep both crankshaft and rod as are and, in case I should need them in the future (knock on wood) I will have it machined then. That's all for now.

In the meanwhile, a little cosmetic won't hurt (even the eye wants its share, as we say here in Italy, I'm sure you have a saying for it, too ;-) ) Yesterday I dropped the front differential, which seems to be mandatory, since otherwise the oil pan won't allow enough clearance for the engine come off. A pain I wish I could avoid, but did it in the end. Also, I'm thinking about blanking the EGR with a 2c coin, since I have the engine off the car. Any advice about this and how to do it properly will be greatly appreciated. More photos will come.

Hi! As you can read here in my "new member" introduction post, http://www.nissanpathfinders.net/forum/topic/44173-wd21-from-italy/, I'm slowly restoring my '89 WD21. Some of you might like to take a look to some photos of the "work in progress", so... My engine developed a rod knock which I believe is due to debris from a broken timing chain tensioner which clogged oil passages in the crankshaft (I will check this later). Anyway, I decided to buy another motor. Z24 engines are very rare in Italy (where offroads vehicles are mostly diesel because petrol prices being insanely high); the only one I could find was 700kms away. I could have it shipped, but did prefer to go to pick it up in order to check it as thoroughfully as I could (was off the car). Crank was good, compression seemed to me a bit low (turning it by hand), but was very clean under the valve cover and decided to take the risk. After all, I can always use the head from the other engine in case compression leaks should be imputable to the head. As said, in spite of the dirt on the outside, the inside is super clean, surely a sign that the engine had correct maintenance. Oil pan super clean, too. Clutch is pretty worn The engine will receive a new timing chain kit, new spark plugs, new oil seals, new air and oil filters, new distributor cap & rotor, a new clutch and 0w40 full synth oil. Water pump and crank pulley, slightly bent from the impact (the engine is off a crashed car) will be taken from my old engine (this will be a budget repair).