Dave WM

I quickly tried it, very low pressure air, could hear leak but could not see any bubbles from water/soap. Yes too much pressure and I suppose you could blow out a seal (front or back). I will post up if I develop a massive oil leak.

Hmmm I wonder if simply plugging the exhaust tail pipe and the air cleaner would effectively seal the engine? less fooling with unhooking stuff. Then add smoke at the brake booster port.

Nice fix. Now redo the vacuum gauge and see if it looks steady and more in line with what the vacuum should be. I presume all the other stuff like removing the oil fill cap now works as it should.

Mine was missing, I got a correct one for it recently and decide it was time to install. well after about an hour of fussing with it last night I decided a different approach was in order. 1st remove the ECU and disconnect the fuel relay plugs. This gains a bit more clearance. next glue in the little plastic thing that mounts to the top of the dash, used some gasket cement. This keeps it from dropping out just at the wrong time. hook up the SHORT side of the spring to the clutch pedal (I presume this is correct, same as the brake IIRC). and maneuver the spring over the into the correct position. Depressing the clutch pedal makes this a bit easier (the attach to pedal part that is). Now the fun how to stretch the spring and hook onto the plastic piece attached the dash frame. I used a long flat blade screwdriver and carved in a small divot using a dermal tool on the side of the blade near the tip, this lets you hook the spring and move it up and down whilst extending it out enough to catch the hold point. took about 20min total getting everything out and back in, the hooking part was the fastest part of the process. Anyway a small victory and a much better feeling clutch pedal.

the dremel may work, doubt you could get the cut full length of the nut due to the manifold getting in the way, but I bet you could get 3/4 of it any way then use the nut splitter to open it up with out the need for power tools.

I used the nut splitter AFTER I snapped of and had it on the bench. as installed getting the splitter on is still possible but getting the impact driver hooked up no so easy. It get real cramped in that space by the time you get the splitter on (its about 3-4" long, then the impact socket, so you have to try to figure out a combo that fits and lets you get the impact driver on it as well. Of the 3 nuts on the down pipe, the middle one seems the best shot, the back not so easy and the front I cant really tell since it was the one that was broken off.

after snapping one off (and deciding to call it quits before I do any more damage) I decided to try the nut splitter on the brass nut from the snapped off one. No joy with hand tools but with an impact driver it split that baby in seconds, then it came of real easy. Now the issue is how to get the impact driver on the nut splitter with everything installed and not loose out it the open. I am pretty sure the back the middle one with a swivel joint and extension with the windshield washer door up you could do, the other may be more of a challenge. just FYI. I plan to take it too a shop at this point since my confidence has been shaken. I presume the correct approach is oxy/acty torch.

Plan B go to a local muffler shop to see what they would charge to loosen up those done pipe nuts, and get the snapped on out.

will do, plan to go some time next week. I attempted to get started on the trans swap, car on jacks, penetrating oil on exhaust studs (remove exhaust pipe for access) impact gun, promptly snap off nut.... enough of that I will take it in and see what its going to cost. I prob should have heated with oxy/ace torch, all I had was a propane, not hot enough i guess. Anyway enough of that. I will check them out and let you know. I would have thought there would be more folks here that have used them.

rev up engine hold at say 2k. I am assuming you can get it running well enough for this. load test, load test, load test....by disconnecting one spark wire at a time. listen for a noticeable change. should be a drop of about the same RPM and miss that is consistent with each plug disconnected. You really need to determine if its a overall cylinders issue or just some not working. Then you have something new to consider.

An air leak so bad that it would not be effected by removing the oil filler cap should be noisey as heck.

been in bus since 1980 looks like, he is the owner. I will drive by and talk see how it goes. I don't mind paying as long as I know its done right.

http://www.ztechorlandofl.com/ spoke to Avi (sp?) still there. He said bring the car by during the week, with the transmission to discuss.

Prob been covered before, I searched found some old data. I keep putting off doing my trans swap (rear main, clutch, trans swap 5 for a 4 speed) due to fear of the unknown. anyway looking for good shop that knows how to work on old Z's (1975 280z). Found a website for Z tech in longwood FL. any others, looking for feed back on Z tech or other shops for this kind of work.

you can load test by reving the engine if it will run better above idle, run the AC and lights to load it down some. Changing too many things can lead to issues, before replacing all the injector wires see if you can hear them ticking. FYI when I was replacing the injector boots (yes just the boots, the plastic parts were fine), I ended up with a ruff idle. I was doing ONE injector boot at a time, would start the car and make sure all was good. well on #3 I must have not fully inserted the metal socket back into the boot cause all of a sudden I developed a miss. Easy to find since I had just done one thing so all I had to do was check that. Lesson being unless you are real good at diagnostics its best to only change one thing then like the eye doctor says "better or worse". I am still thinking you have some clogged or non functioning fuel injectors (wiring or injector, maybe even ECU if you have the leads swapped around) from what you described in the prior load test, I would try to confirm that before doing too much more. The problem with the noid light test is it will only confirm a pulse of electricity to the injector ( a good thing but not definite proof of a working injector) hearing it tick will confirm the pulse and a reaction from the injector, still not definite since there is no way to know its not plugged up. the only way to know for sure is to test them out of the manifold under fuel pressure with a pulse so you can see the spray pattern. This is quite a bit of work and is why I think the load test is important as you only want to do this if you are SURE that its isolated to one or more but not all the injectors. If all the injectors were not properly metering fuel I would look to pressure, signal, duty cycle (AFM/ECU). Don't forget the CSV I don't recall you saying it was checked that is easy, pull the two bolts out (don't drop them in the manifold) pull the CSV up and look at it, is it leaking at all while the car in running, it should ONLY fire when the key is in the start position and then ONLY if the engine is cold, like less that 70f. The remove the oil cap test is a good one as well, a well running engine will stumble and die at idle that is assuming the emission stuff is hooked up.

1st thing to try if the gauge is not working would be to simply test it by removing the SINGE wire bullet connector at the temp sending unit, and ground it. This should make the temp gauge swing fully to the right (hot). this verifies that the gauge itself it working. If to does not move then you need to look there. If to does move then it could be the sensor or the wiring or the connections. at the sensor. You should consult with the FSM to make sure you know what sensor you are to be looking at for the gauge. The FSM is VERY complete and will walk you thru what I just described.

you should get a service manual, it will help you with what does what.

different things. there is a temperature sending unit for the temp gauge there is a thermotime switch for the cold start circuit there is a temp sensor for the EFI enrichment circuit.

fyi easy way to compression test, get a momentary push switch, get a few feet of 2 conductor hookup wire attach one end to switch, the other end put a alligator type clip and a female spade connector. with car in neutral , disconnect the starter solenoid wire and use the swiched wire to activate the starter (female end to starter solenoid spade, alligator to a positive supply (right there on the starter if you like). now you can turn the engine over with the key in the off position. I use this sometimes when adj the valves as well to bump the cam shaft around.

back to a dead cylinder (if you find one that fails the load test), since you have checked for spark, next check for fuel, start with a stethoscope and listen to the fuel injector, should hear it clicking away, compare to the others. If you have a dead cylinder and you have compression and spark, then it pretty much has to be fuel. If the injector passes the click test, next up would be to pull it and do a flow test. But don't do any of this without conducting the load test 1st.

load test the white plug cylinder. See if that one is dead by pulling that plug wire off with car idling, does it change it idle, it should. make sure you have the correct plugs, with the correct gap, correct heat range, use new ones, try again and note if they look carbon fouled. for over rich check fuel mix which is what it looks like, check water temp sensor AT THE ECU resistance, compare to chart in the FSM for correct reading given water temps. CONFIRM operation of CSV (pull it out and check for leaking) check Air filter to make sure its not clogged, seems like the AFM would deal with this but what the heck. check fuel pressure regulator, confirm pressure 36 psi engine not running but pump on (pull starter solenoid wire and turn ign key to start, read pressure). check pressure again with engine running, should be somewhere near 30 psi. Reseat the ECU 35 pin connector. when all else fails (all sensors are reading right at the 35 pin, and reseating does not help and you have eliminated ALL other possibilities like fuel pressure/CSV, then consider the ECU itself. hopefully no one has monkeyed with the AFM settings.

my 2 cents, fix it with out having to rig something up, one issue at a time. Its not that complicated, just a relay and the ignition switch (at least the start position) like zh said before, disconnect the starter solenoid wire, have some one turn the key to start, begin tracing to see where the problem is.

compression check should be one of the 1st things to check. A load test by disabling one cylinder at a time is quick and easy too. May point to a problem isolated to just one cylinder.

ditto, put the old one on since that is when the prob started.

yes went on easy seem to work well on my 280z