Zed Head

Just to tie this up and for anyone else that wondered, here are a few pictures. The resonator (actually an anti-resonator I believe, by definition?) does neck down a little at the inlet then back out at the outlet so does create a flow restriction. But the interior is pretty smooth. There are some holes in the interior but no "teeth" to create turbulence. For those interested in the esoteric Z stuff... (and of course, the obligatory shoe photo - Asics)

The water temp sensor tells the ECU how long to open the injectors. The colder it is the higher the resistance value. If it goes bad, giving infinite resistance, or you have a broken connection it will tell the ECU that your engine is stone cold and the ECU will continue to pour on the gas. Page EF-23 and EF-32 of the 78 FSM describe the test procedures (sorry, the 77 FSM is too hard to find things in). Measure across Pin 13 to ground. If you get infinite resistance you probably have a bad sensor or a bad connection. Resistance should be about 2.5 k-ohms at 70 F. 76 uses Pin 13 also so it's a good bet that 77 does too. The thermotime switch just cuts powers to the cold start valve if the engine is warm or if it's been cranked over recently, I believe.

Thanks for the insights ZCurves. I will try to avoid the Olds sound, but am not ready for Twice Pipes. Baby steps.

I have a complete original exhaust system from a 1978 Z that I am going to install on my 1976 280Z, non-CA model, to replace the original one, since someone smashed the exhaust pipe up against the differential when lifting, to about half volume. Plus the $30 O'Reilly's Cherry Bomb turbo muffler just doesn't sound right. Could anyone tell me what is inside the small "pre-muffler" up next to the transmission? The little mini-muffler. It looks to me like a place-holder for the California model's catalytic converter. Is it just hollow or does it create a flow restriction? If it's hollow I will just get a new muffler and install it as is, saving on gaskets and effort. If it is a significant flow restriction I will replace it with something else before installing. Thanks for any comments.

I have a flare wrench too but it has not always worked. Looking at those pictures, it may be vise-grip time. Once the points of the nut are rounded the wrenches are less effective. If you take great care in placing the vise-grips, and make sure the jaws still have good serrations, you can break those fittings loose with minimal damage. If you feel the grips slipping at all, stop and reset. And before you start, you should file the twisted off points of the brake fitting nut down flat to give a good gripping surface. The actual twisting of the wrench or vise-grip is 5% of the time involved. Getting the grip set is the other 95%. I have actually filed new serrations on my old vise-grips to get them to do the job. Clean the vise-grip jaws and the nut of any oil, grease or fluid. Any slippage at all is bad. Get everything set, double-check, then apply twisting force. If they are that tight, you may also bust a knuckle when it lets go, so have a band-aid ready. You can get pre-cut lines with the right fittings already flared on at most auto parts stores, for the short hard line. They are inexpensive. I made a bending jig with screws and wood but you can borrow real bending tools from the parts stores. Just take the old piece in to make sure you get the right style and length. If you decide that the hose is coming off no matter what, you could use a torch. Put a torch on the big end, watch out for bubbling brake fluid. Of course, once you bake the rubber hose, there is no going back.

sblake - I was joking about Tony D. By alter ego I meant the opposite of. From what's been going on over at Zcar I thought maybe someone had had enough and was stirring the pot a little bit. I meant no offense to Tony D, these guys aren't even from the same universe. If you were going to create two fictional characters to stir people up, these would be the two. When I read rzkas's posts I though "Is this guy real? Someone is messing with the forum." He breaks every rule of a good post - format, spelling, coherence, doing preliminary work - but he is just nice enough to get people to try to help him. Or was, I notice that his last post had 0 replies. ChrisS30 is the same. The first post was total immature nonsense, hard to believe that the person who wrote it could even find this forum to ask the questions. But again, just good enough to get some help. If these are fictional characters, the creator is a genius. I have to say that the Tool Shed concept over at Hybridz is a good idea. Keep the threads clean and purge the nonsense quickly.

I think that rzkas and ChrisS30 are one and the same. It's a test. Do I win a prize? (Maybe Mr. Tony D's, from Zcar, alter egoes?)

Vise-grips will work but you have to get it right the first time so you don't round the fitting end off. They do get freakin' tight and when they let go you'll think you broke it. Edit - it might help to take the hose end out of the mount so you can get a wrench/vise-grip on the big fitting and the broken end. Set the wrenches/vise-grips up so that you can squeeze them together rather than pulling on them.

Yes, that is the ECM. I have the same wires, non-connected. 1976, manual transmission. I looked closely when I was working on mine and decided that they weren't meant to be connected to anything full-time and just pushed them back under the cover. I could be wrong. That was quite a while ago. Maybe they are for diagnostics or a switch bypass.

It might have been the fuel pump switch in the AFM. When you turn the key to Start it is bypassed and the fuel pump is powered to start the car. When you let go of the key and it goes back to On, power to the fuel pump is supplied by the fuel pump switch in the AFM, which is allowed to close when the flapper opens in the AFM. If the contacts get dirty the power is not supplied and the car dies. It happened to me, with a new AFM. The car would start then die after about ten seconds unless I hit Start real quick (painful grinding noise) to energize the pump again and get the fuel pressure up. I had to clean the contacts to fix it. This was after I drove the car home with my fuel pump powered from my defroster circuit. Luckily I had enough wire to reach through the hatch and under the car. Sorry I didn't chime in sooner, you could have checked it out. But you were already pulling your gas tank, by the time I got here.

76 uses a contact switch in the AFM to kill power to the pump when the engine is not running. If you take the black side cover off, you'll see it, it closes when the AFM flap opens a few degrees. Move the counterweight and you can see it working. I have had the contacts get dirty and not close. Had to clean them up with a match book striker, they're small.

It's not the plate that goes between the transmission mount and transmission? That's what it looks like. Not sure what you mean by "lined up."

Different years use different power control to the pump.

1976 has the 3.54 R-200. You would need the half-shafts, mustache bar, etc. to use the R-200 in your 240. I think that you'll need 12, 14, 17 and 19 mms to get the various nuts and bolts off. The standard manual transmission for 76 was a 4-speed also, so you probably won't find a 5 but you never know. And, not to be more of a downer, the 76 alternators were externally regulated too. But the alternator looks to be higher output than the 240 (I show 72 as 50 amp by the FSM and my 76 came with a 60 amp), so it might be a bolt-in upgrade.

To tie it up - I replaced the transverse link bushings with polyurethane, and left rubber bushings in the back on my T/C rods (for the reasons jmortensen proposed) and kept the urethane in front. The steering is now much tighter and the wheels don't shift when I hit the brakes, like they did before. So I came out ahead, overall, after the motivation of the broken T/C rod. FWIW, even with the old rubber bushings off, it is hard to tell that they are bad. You can stick a big screw driver in the center, brace it and reef on it to get them to move, but it's not obvious. The cracks in the rubber are only visible when it's stressed. By the way, a Truecraft 27mm 3/8 drive socket, part #45227 (manufactured in the early 80s, may be different now) is a "too perfect" fit for pressing out the complete bushings from the transverse links. Too perfect because it takes as much force to press the socket back out as in, but it's easy to fixture the socket with a bolt or rod to press it back out since it is solid and you can press on the center. But it fits the outer bushing ring perfectly. Thanks for all of the input.

Quoting myself above. Kind of nonsensical. Four small bolts plus one big one - I'll just take the LCA off...

Thanks all for the comments. I feel comfortable now with poly front/rubber back, although the steering does feel looser. Replacing the LCA bushings will probably help that, I'm sure. ktm, I'm just telling a little story here, and trying to add to the body of Z Car knowledge, with some pictures and solid facts, for anyone to use as they choose. That's all. No intent to offend or ignore anyone else's hard work.

Good point, thanks for adding. I did notice that my control arm bushings were worn also, with visible cracking, and thought that it may have contributed. Before I took the broken T/C rod off I found that I could grab it like a handle and move the control arm around easily, with play visible in the control arm bushing. The end of the broken rod actually hung about an inch below the bushing mounts because of the worn control arm bushings, so there was probably a side load on the rod also when in use. I didn't want to do the control arm bushings yet so just went with the rubber in the back for a short-term fix. Has anyone replaced the bushings with the arm still in the car? I enjoy laying under my car so might try it...:classic:

Changed mind on comment...

Here is a picture of one more Z car T/C rod gone. I installed MSA polyurethane bushings front and back on the T/C rods of my stock 1976 280Z about 4 months ago and have put about 3,000 fairly easy road miles on since then. I had read the various accounts of broken rods but the evidence still seemed iffy and most of the descriptions seemed to be for the later model cars with front-oriented T/C rods and not the rear-oriented Z cars. So I decided I would do both sides with polyurethane on my car and see what happened. It looks like fatigue cracking started top and bottom and just worked its way through the bar. The coup de grace may have been when I backed the front wheel in to the curb while parallel parking. About ten miles later, that evening, I heard something bumping off the bottom of the car, but had not seen anything in the road. So I took a look under the hood in the morning and saw that the rod end on the passenger side was almost worked out of the bushings, the rod was broken at the base of the turned-down end, and the big washer on the inside was gone. That was the noise. I had a spare rod from a 78 and used the rubber bushings on the back on both sides, in place of the hard polyurethane, as described around the various forums, to take some of the bending pressure off the rod end. For the record, for those still wondering.

The fuel pressure regulator (FPR) has a vacuum line attached to regulate fuel pressure according to manifold vacuum. Yours looks like it is probably working correctly. If you want to check the FPR, you can pull the small wire from the starter (it comes off by hand, no tools needed), then turn the key to Start to run the fuel pump. The fuel pump will run (you'll hear it), but the engine will not turn over. Without the vacuum from the motor, the FPR will give a higher pressure. 36.5 psi is normal for 1976 and most years, I believe. A lot of people have the problem with rough idle after starting a warm engine. I have seen one proposal for vapor lock but no followup. Have not seen a good remedy yet.

It could be that your front or rear brakes are low on pressure. Either leaking or need bleeding. There is a valve that measures the balance between the front and rear systems and activates the dash brake light if the balance is off. I had the same problem on my 76. Found out that a PO had put the front calipers on the wrong sides, making them impossible to bleed correctly. I could pump the brakes up while driving and make the light go off, but it would always come back. Here is a page from the FSM describing the system. 74 260 Brake Page.doc

Hey Jennys280Z, does your car actually run like it used to now, and run well? I'm curious since your AFM resistance readings were the same as mine, which was definitely bad. Just trying to learn something. Thanks.

Post #3 in this thread, Chris's writeup with pictures, will help you guys out a lot. The pictures show where the clips are and how to get them out. The clips are on the inside, unlike most American-made cars. They are probably covered in old grease and dirt, hard to see. http://www.classiczcars.com/forums/showthread.php?t=27855&highlight=u-joint

I live in Portland Oregon, fairly cold up here, and have been driving my car all winter with the cold start valve fuel supply disconnected. It just takes a 1/2 second longer to start but once it's going it's fine. I will not be reconnecting it. I think that it may have been leaking a little. The left over fuel supply line makes a good spot to install a fuel pressure gauge.