alternativez

I'd pick up a used one with knowledge that it's working and correctly matched to your engine. Plug it in and see if the problem is fixed. Could be a poor wire in the connector?

Once resolved an exasperating no-start problem on my '85 BMW 635, finally determining the problem to be inside the ecu. By that time I was fearless or desperate, so I judiciously reflowed solder in suspected circuits. Worked in my case. Hope this is relevant. Good luck!

Wow! You've done an amazing job with your z, and it was surely a cool and exciting reward to take it on vacation! Thanks for sharing the story through this excellent thread!

Pick up a few feet of good quality small diameter vacuum hose at the parts store and cut to lengths. Larger moulded stock pieces you can get from your dealer or catalog. It's good maintenance to check or replace them due to age and operating conditions. They may appear decent, but soft hoses can collapse, and brittle hoses may leak at connections and at minute cracks, especially in cold weather.

I haven't worked on the L24 for a long time, but this sounds like the intake is trying to compensate for an air/vacuum leak. Check for loose fitting, hardened, softened, cracked vacuum hoses large and small and one-way check-valves. I'd say just replace all hoses due to age, but checking them while the engine is running will identify or eliminate where the problem is, if it is. Hose to mechanical advance in the distributor would be a good place to start. Also, I'm pretty sure those throttle return springs should be equal. Good luck!

The 280z has a ecu? I'm not so familiar, but I'm assuming it does. The ecu is the heart. Do they ever fail? Wild chance, I suppose, but I spent a month once with similar problem, different car. Checked and rechecked everything related, components, circuits, absolutely drove me nuts. Finally, i hit on the thing all manuals say to leave alone, the ecu. I took it apart, and of course it looked fine. Then I discovered my other car had the same ecu. Swapped them; car ran perfectly. I figured luck was on my side, so I judiciously reflowed some solder on the "mother board" and it was fine. Not prescribing this as your route, just maybe to say, don't overlook old electronics and the central component. Good luck!

6. Keep the fridge stocked. I think you shouldn't worry about replacing the core plugs just now. You can check compression as long as your timing chain is properly aligned to cam and crank and with tension. See your engine book. I'm hoping you find no fluid on the cylinders and no loss of compression at any piston. I'd be getting the pan off, if only to clean that goop out. Examine everything for anything suspicious. You haven't said if the motor uses oil frequently or leaves puddles or has seeps, only the small coolant? leak up front. And no white exhaust, which likely be steam from vaporized coolant, or blue, which would likely be oil. Yet, absence of proof is not proof of absence. Gotta be sure. I'll bet somebody knows what this problem is, and they're waiting for you to figure it out. Good luck!

And more zip locks. Daniel, are you still dead set on (A) changing the head gasket, or are you interested in ( repairing your motor? If you answered A, ignore this post, if B, I hope you have not removed the head yet. I suggest putting your timing chain right, too, if possible. You really should get compression readings for each cylinder. Can you take out the spark plugs and check for coolant in the cylinders? If so, use a syringe and piece of clear tubing, like for an aquarium pump and see if you can syphon it out and spray something to absorb the coolant and lightly lube the cylinder walls. Of there is no fluid in there, you and I will deserve one of those beers. I also suggest removing the oil pan. Check it carefully for shreds, crumbs and chunks of steel, aluminum, any thing. If nothing, I think we should have another. Could you post pics of any parts you've removed, especially inside, mounting surfaces, water pump for example. Get same for block. Get pics of the block from several views. Get your radiator pressure and flow tested. Do whatever you can to determine the cause of the coolant in the oil. Sorry for long posts. Cheers! Jim

Daniel, take detailed pics of everything as it is, before and during assembly. Don't assume anything is correct on your engine, such as hose connections. This is zen stuff. Patience and perseverance are valuable tools.

Mike, Beautiful car! Great wheel/tire set up for a potent looking stance. Your son has good taste, too. The pilots are the top choice on my wish list for my '70 z project. I've had michelins, but not pilot sports, on a high spirited '76 BMW 2002 for a couple of years, and I just can't wear them out! Mine are great except for snow traction, but I have dedicated snows for Midwest winters; not so relevant in Texas, I suppose. Any feedback from your driving on the pilots? Are they everything one expects from Michelin, partularly on the rwd z? Quiet on highway, I assume?

This is perplexing; I recommend more troubleshooting, at least some info about your latest sequence. Was the coolant at the proper level in the radiator before you drained it? Any chance you pressurized the cooling system before you removed the radiator and water pump? Did you remove radiator, then water pump and thermostat? Removed block drain plugs? Did you collect all that coolant? Earlier you had reported no oil in the radiator. Was there no oil in any of that, just good, clean, bright green coolant? So, with three gal or more mixed from the oil pan, how much fluids were in the engine and radiator? Have you removed the oil pan? Have you noticed any evidence of steel or aluminum shavings or bits? Are the insides or mating surfaces of any of the parts or block badly pitted or corroded? I favor defining the cause of the problem or at least an informed hypothesis and using further disassembly to gather as much fact as possible. You may well end up replacing lots of parts to correct the problem, but you don't want to replace a lot of parts and not correct the problem. You pretty much have to imagine or know what all the possible problems could be and eliminate them, and this is likely a combination of problems. As you started with a "hack job," I imagine you don't want to end up with one. I think you have some empathy here because many of us have decades of personal and professional auto mechanics experience, yet we've all had to learn a lot of it the hard way, as you seem just as willing to do. I don't usually hang out on forums, but I'm literally laid up with some muscle injuries, so I've been very interested in your story. I do hope you get this figured out soon, before I'm back on my feet! I'm still looking for reasons why coolant has been pumped into your lubrication system, but doesn't seem to have returned as that mixture to the radiator, and doesn't seem to have made it into the compression chambers. Good luck!

I admire your spirit. I know you're pretty tied up; maybe spare a few to put up some pics? Wish we'd had the internet when I was young. Woulda saved me a lot of trouble. Good luck!

Indeed. I'm out. Pretty far from Indy. Perhaps now someone local will pick up on this. Good luck.

If coolant has contaminated the oil, as it seems to have done, either as the engine was running or just sitting for a while, that answer has many parts. Have you been driving the car prior to discovering the problem? Don't try it, but do you think it would start and run now otherwise? You need to know if your engine is damaged in order to know what you need. Otherwise, you assume the worst and study up on rebuilding your engine. A first hands on step would be to drain the oil pan to see how much coolant has gotten into the oil, and drain some coolant to see how much oil is in the coolant. You will eventually be draining both entirely, no doubt. Once you get some specific task to do, there are excellent threads on this site to help you. You will also get good advice. Several threads are documenting engine rebuilds right now. I've not actually worked on an L24 for a really long time, so I'm just trying to help you with a a little general diagnosis. Sounds like you are willing to conquer this, but you need many parts like gaskets, thermostat, hoses, etc. You do need to determine the extent of problems and the extent to which you reasonably will have to go to repair. A professional estimate by a local shop is recommended. The more you can tell them will help them figure it out. Good luck!

Milky fluid on the dipstick and in oil pan,too? Please provide a little helpful history, i.e. How did you arrive at the point where a car seems only driven briefly or slightly has this problem? Was it being driven and something happened? How long has the problem existed? What condition is the car in general? Pretty much dead? A beater? A project? Usable for daily driving? Taxi? Won it at cards? Just kidding. Update though, if you will. Seems like you may have to do a little more than just change a gasket. Say you didn't take your uncle's spotless toy out and slam it around while he's out of town. Still DIY, what with a garage, beer, tools, and oh yeah, desperation? You're ready. Psst. Fly me (and my wife, of course) first class from Indiana and put us up comfortably for as long as it takes (read the fine print) to put this vehicle to rights, all meals and clothing allowances and customary day trip stipends included, of course...Sorry, not presently in the market for offspring, however, as your earlier post suggests. I hope I'm safe presuming you still have a sense of humor, a great ally at times like this.