kensval

Just pored over the wiring diagram again. It's apparent that it really only needs to go to ground. Yet another place to clean up the P.O.'s questionable wiring skills. Thanks for your help. I also think I'll connect the BCDD to the yellow wire as it should have been before, and see if I notice a difference.

The 1976 wiring diagram seems to indicate that it goes to ground on the female bullet connector side. However, when I pulled the engine to have it rebuilt, I marked that female bullet connector DIST. Could it have been grounded to the distributor body? Should it have? The original owner of the car did some pretty messy wiring, so it's not always clear which wiring was original and which he had altered. For instance, he had the yellow wire for the BCDD hooked up to an electric fan in front of the A/C condenser.

My 280Z has a D6F4-01 distributor. The three leads at the end of it's harness are all the same color of blue, but I at least have them marked as to where they go from when I tore the engine out (they go to the terminal block near the front of the left fender well). My problem is the female half of a bullet connector that leads to a small condenser (which is close to the terminal block for the three blue distributor wires) that I marked "Dist" at the time I pulled the engine. I need to know where the other half of this wire would connect to the distributor.

That's what I thought, thank you. So then, when the distributor is back in place the rotor should be roughly pointed to the #1 position on the cap? I'm used to Chevy V8s, it works different for them.

Just to clarify... that's 11:25 when looking down into the dist hole from the induction side of the engine, right?

I have a '76 280Z. The (original but no longer bone stock) engine just came back from the rebuilder, but I think they got the oil pump/distributor installation wrong. The rotor does not point to the #1 position on the distributor when the #1 cyl is at TDC, but rather to the next cylinder position in the clockwise direction. In researching how to make this right, however, I'm seeing two different sets of instructions on installing the oil pump which sets where the distributor must go. The 1976 FSM says to line up the marks on the oil pump and the dist drive shaft then pull it out slightly and move the drive shaft one notch counterclockwise. Other sources I've seen on the internet say to just line up the dots on the dist and the oil pump drive shaft and install it that way. So, which is it? It looks to me that perhaps the rebuild shop just lined up the dots, and moving the shaft one notch back would solve the apparent alignment issue. I spent a lot of money getting this engine done, so I want to make sure everything is done right when I finally get to start her up. Thanks in advance...

I checked this thread out hoping to find a link to a detailed list of fasteners for my 280Z. I'm in the middle of reinstalling the engine after a rebuild, and would like to be able to go to the bolt store and get replacements for some of the fasteners on the car. Some I'll re-use, and I don't really care about the look or finish, just the strength of the fastener. Does anyone know where I might find such a list?

Thanks for the replies. It's a stock N42 head, stock height Fel-Pro gasket. I didn't realize the dish of the piston would not factor into overall displacement. Here's what the calculator spat out, after I added the overbore: Block Height= 207.87 mm Deck Height= -0.07 mm Chamber Volume= 44.6 cc Cylinder Volume= 458.9 cc Gasket Volume= 7.86 cc Dish Volume= 0 cc Deck Volume= 0.41 cc Uncompressed Volume= 511.35 cc Compressed Volume= 52.87 cc Compression ratio= 9.67:1 Total displacement= 2753.37 cc A different calculator I found today gave me a compression ratio of 9.975:1... may as well say 10:1. Have to be a little careful with the fuel and the timing I think. The bottom end looks stout enough, anyway, and I put in the good ARP fasteners with the rebuild. Now can anyone tell me what the new HP should be?

I've just had the stock L28 out of my '76 280Z rebuilt. It had to get punched out by 30 thou, and the dished pistons were discarded in favor of flat-tops. Can anyone tell me what the CC's on the stock pistons would have been, or even just tell me what my new displacement and compression ratio should be? I guess I'm also going to have to figure out what kind of timing to run with the new compression ratio. I was using premium fuel before, and now I'm going to need it for sure.

What are they charging you to restore your dash? My 76's dash needs work.

I bought some 10mm x 1.25 metric bolts to attach the engine to the stand, but the bolts will not thread into the block. The threads are too fine. What's the next coarser thread spec for the 10mm bolt... 1.0?

Thanks, Jim. Too bad the 240 ones can't be adapted. Eventually MSA or someone else will start making them for 260s and 280s, too.

Has anyone seen advertised anywhere a replacement fuse panel that will work with a '76 280Z, and uses modern blade-type fuses instead of the old glass ones? My existing panel has a badly melted cover (the previous owner took some liberties with how to provide power for accessories he added), and all the writing is in Japanese anyhow, so I don't know what circuit does what. I've seen blade-type fuse panels for the 240Z up to '73 on the MSA site, but nothing for newer Z cars.

Here's another possibility (this happened to me): If your carbon canister is gone, and the vent line from your gas tank is hooked directly to manifold vacuum, then the pressure in your gas tank is being lowered not only by the reduction of fuel in your tank, but also by the manifold vacuum. Eventually, you starve your engine of fuel and it won't restart until the pressure equalizes. (I did not hook my vent line to the manifold, a supposed local Z-expert shop did. Not so expert.) Other possibilities: Loss of signal from the ECU due to a cracked PC board that expands when it gets warm, cutting off the signal to fire the injectors; an intermittently bad fuel pump; bad throttle switch. Good luck.

Thanks for the quick response! Though I'd find the info in the FSM, but I did not. K

Can anyone tell me the metric bolt size for the bolts holding the tranny to the engine on a 280ZX L28 engine? I just bought one for a spare engine for my 280Z, and intend to mount it on my engine stand. I'd like to have new Gr.8 bolts on hand ahead of time, but don't know the bolt diameter and thread pitch. Thanks in advance!

In your case, because there's already water in the oil, drain the oil now. You will absolutely have to waste an oil change to clean the system out. $300 sounds downright reasonable. My own L28E head is at the machine shop right now, and I don't expect to get out of it for under $700. I bought a 280ZX engine today for $150...and it runs. There are definitely bargains out there to be had. Got the engine from a member of my local Z club that needs to clean out his garage. Keep that in mind if things go from bad to worse when you get the head off... you have options. Well, back to polishing my valve cover...

Generally speaking, a car with a bad head gasket will start. If the leak is so bad that enough water to cause a hydrolock enters a cylinder, then the engine might not start, and you should be glad that it doesn't. Water cannot be compressed, so if your cylinder is full of it, and the piston tries to come up in the bore anyhow, something's going to break. Might be a connecting rod, a wrist pin, or the piston itself, but something will break. However, that being the case, a hydrolock would also likely stop your engine from cranking properly. From the sounds of it, you should find someone with more experience to assist you if you're going to attempt to change the head gasket yourself. Since your engine is an overhead cam design, if you're going to remove your cylinder head, you will have to disconnect your cam from your timing chain and gears. If the top and bottom gears somehow become misaligned during reinstallation of the head, your engine will be improperly timed and likely will not run and may even do damage to itself. (Perhaps someone else viewing this forum knows the piston-to-valve clearance of a stock L28E... I don't) Providing you get your head off without screwing up your timing, your head will still need to be checked out at an automotive machine shop. I submit to you that this is not even an option. The leak may well have caused damage to the gasket mating surfaces that would render a new head gasket useless, and then there's the need to discover the root cause of the leak. Your engine employs a cast-iron block with an aluminum cylinder head. Because the heat expansion and retention properties of cast-iron and aluminum differ greatly from one another, stresses are created when the engine is run that tend to cause the head to want to change shape. Normally, your head bolts are more than tight enough to prevent this from happening, but they will lose tension over time, making the engine more prone to this kind of damage. So, the head will likely have a little warp to it, and will have to be resurfaced to make it straight again, or the new gasket will leak almost right away. I would also highly recommend that you use new head bolts or studs. Using the old ones is a recipe for disappointment... every time. Because you say your oil is milky, I suspect that either your head is badly warped or it has a crack. Both, if the damage is not overly severe, can be repaired. Again, you'll have to send the head to an automotive machine shop. I would call around for one that specializes in Japanese engine work. As for your oil, I would recommend that after all the work is done you change out your oil and filter, run your engine under no load for a short period of time at normal temperature, dump the oil hot, and change the oil and filter again. You might also look into a special oil additive flushing agent to use with the first oil change to help clean your engine out. You want to do everything you can to get rid of all the emulsified oil/water in your engine. Since this could all run into quite a bit of money and trouble, you might also consider getting an entirely different engine if you can find one at a wrecking yard. You'd do best to find a yard that pulls and tests their engines so you'll know what you're getting. You need one from a 1975 or newer 280Z, or the head won't have the notches for the fuel injectors. An engine swap is easier to do for a novice mechanic, and you can always save your money up to have your original engine completely rebuilt at a later time. There is one last, way cheaper option available to you. It carries about as good a chance of screwing your engine up as fixing it, but you might not consider 50/50 odds all that bad, so here it is... Look for a product called Iron-Tite. It comes in a white bottle, is a clear liquid, and is an antifreeze additive like you mentioned looking for. I have actually used this product on two engines in vehicles I wished to spend no money on and didn't care if I killed in the process. Provided you can troubleshoot your engine to get it running again as-is, you just pour it in, get your engine hot, run it that way for 10 minutes, shut it off then let it sit for a few hours or overnight before running it again. It causes a reaction with the metal in your water passages to remove some of it and keep it in suspension in your coolant. The suspended metal gets clogged up in your leak and cures when you cool your engine out. The result can be a stopped or severely reduced leak, but there are NO guarantees. It could also screw up your heater core, react badly with the aluminum, plug some of your rad passages... you get the picture. Use it at your own risk. It'll also make the engine harder to clean out if you do eventually find the dough to send it out for a complete rebuild. You've been warned. I used it on a Buick 3800 V-6 engine with a mild head gasket leak on one cylinder bank and about 180,000 miles on the engine. The head gasket stopped leaking for over a year, and we drove the car from Saskatoon, SK, Canada to Minneapolis, MN and back in the heat of the summer with no trouble. I drove the crap out of it and it held... for a year. Again, I knew the chance I was taking when I used it, and if it hadn't worked I had other options for transportation and the car wasn't worth spending money on to fix correctly. Anyhow, that's my long winded 2 cents worth. Good luck.

I can't recall exactly where I found mine, but it was a free download, and not hard to find using Google. I'm no expert, but you may have two bad pin connections at your ECU.

Do you have the factory service manual for the car? I have one for my '76, and it details many tests you can do to troubleshoot problems with the EFI system. A good number of things can be found by doing continuity tests with a multimeter on your ECU connector. You should be able to find the FSM in PDF format on the internet for free. I don't know if the EFI from the '78 and the '76 are identical, but I checked my diagrams and the #3 and #6 injectors are connected to different dropping resistors, so likely there is no problem there. I would definitely check the connection to the ECU. Good luck.

I only recently purchased the car from a guy in Florida. I really couldn't say how well he did or did not take care of the engine. The valve seals do let a little oil out at startup, so the head needed to be done anyway. Did the valve lash not too long ago, and the cam and valve train all looked/felt good. I was going to have the engine rebuilt at some point anyhow. The only difference it will make is in the order in which things on the car get done. Engine this year = suspension next year, and bodywork the year after that. Since we're in the EFI forum, let me ask this... can I remove the EGR valve and blank it off on the intake? I've got a header on the car right now and no provision for EGR from it. It would be nice to clean up the look of the intake side of the engine, and probably reduce the possibility of vacuum leaks in the future, too.

@ Philip: Thanks for your help. Not the news I was hoping for, but not a big surprise, either. I live in central Alberta, so while you couldn't really consider it a "warmer" climate (not by a long shot!), the car only gets driven in the summer months, and so the loop under the air regulator is likely unnecessary. As for the the head gasket leak... Well, with 95,000 miles on the engine, I may as well get the whole thing rebuilt. I mean, if I just replace the gasket, it might not do the trick, but if I'm going to have the head shaved, I may as well do the valves. Do the valves, and the oil control rings will probably start passing from the increased compression... and it just snowballs from there. Probably cheaper to pull the whole engine and have it done in a one-shot deal. Ken

I've got a 1976 280Z with stock fuel injection. The FI was not on the car when I bought it, and I had a shop in Edmonton, Alberta restore the car to FI using parts from a donor car. They did an incomplete job. Recently, I've been having trouble with the thermostat opening way too late. I noticed that the lines that run from the cooling water through the intake manifold (or a piece attached to it, just below the secondary air regulator), were not connected. I got a look at a 280ZX and saw how they were meant to be hooked up, and restored the connections to my 280Z. My thermostat now opens smoothly, but there's another problem. The car now seems to be burning antifreeze until warm. Lots of white smoke from the tailpipe until it's at temperature. Is there any chance that the connections I restored are allowing cooling water into the intake? If not, just what does that cooling water loop do, anyway? Any temperature-based modifications to the FI system should be handled by the temp sensor and the thermotime switch, both located in the thermostat housing. Any help would be appreciated. I plan on disconnecting the water from the EFI intake manifold and looping it back on itself to see if the problem persists. If it does, I've likely warped the head and caused a head gasket leak.