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Two things here I just wanted to mention for the Zsters. My fuel pressure drops off immediately after turning off the engine, however never fails to fire right up. Just in case I have located a Kepner inline check that I plan to try. The second issue I had was much worse my car would intermediately just loose system fuel pressure and stall. Turns out the relay contact inside the mass air flowmeter would open and cutoff the fuel pump, I gave it a slight tweak to the right at it's base with the duckbill pliers and this kept the contact closed. The darn thing had me fix and study every other known condition because of it working on and off condition. I thought it was a blockage and cleaned the entire fuel manifold to the gas tank. Oh well

You could also install a inline check valve, I use them for 2000 psi hydraulics all the time. Think that is what I'll do for my Z has the same issue , injectors are good. So why must it hold pressure once the engine is shutoff? just asking.

I also placed red poly on the front of mine and have driven with no issues, even with stiff Cosmos coilovers on the front (which I am taking off and replacing w/ OEM coils for around town) the cheap coilovers are way too stiff on bumpy roads.

I finally found out that it was truly a MAFM (mass air flow meter) problem, I found a sweet 2+2 thaT had a meter just like it (same model part #) I guess I hesitated buying a rebuild because I had gotten a bad on from a Z shop and the current one on it had passed smog.So musch for that theory. So I cleaned & WD40'd the thing after a quick paint and hit the ignition....presto! started right up with minimal warmup on a cold morning, The main issue before this change was that I had to raise the return line fuel pressure (installed an inline shut off valve) > to set it HIGH: almost 50 psi! (so much for gas conservation) anyway now I set it to the factory spec of 36 psi, Outstanding! I also painted the car a (secret) metallic blue and getting ready to reinstall the stock front springs back on> bye bye front coilovers,you suck. replaced the rear hatch seal it was hard. Then to the rear I go> replace all the suspension bushings (with the ones I already bought) and renew brakes, new seats, ,there will be !#$%@$^% but compared to building and testing Oil drilling product for 20 years this is therapy, in addition to an occasional Coors light and gettin' jiggy wit it! Hope this helps - easy now

Anyone losing thier mind with this sort of thing -See this (keyword:return line)thread:http://www.classiczcars.com/forums/search.php?searchid=489644 Also:On mine I found this also EGR valve system worked per FSM manual checks however further followup reveiled that the EGR diaphram had an almost undetectable vacuum leak that caused much grief, it was found via the propane and small hose method by placing tip just under the EGR housing (hat) that covered the diaphram. F_K ME! My theory is that with the extra air bypassing the metering and management of the AFM/ECU,the fuel pressure then also had to be raised to compensate or for the motor to run smoothly just forget about gas milage!

On mine I found this also EGR valve system worked per FSM manual checks however reveiled that the EGR diaphram had an almost undetectable vacuum leak that caused much grief, it was found with a propane and small hose method by placing tip just under the EGR housing (hat) that covered the diaphram. F_K ME! My theory is that with the extra air bypassing the metering and management of the AFM/ECU,the fuel pressure then also had to be raised to compensate or for the motor to run smoothly just forget about gas milage!

I found that my return line had to be restricted to compensate for the vacuum leak I found in the EGR system, using the propane method I finally found it under the EGR cap around the valve bellow. Using a flow control needle valve fuel pressure was boosted and the car RAN GREAT! Open the line to a normal 36 psi and ran crappy especially at start up when cold. So I basically I need to fix this ? why it is opening when it should be closed, ? not being controlled, or ? just plain leaking through. good support

Use a substitute many aftermarket places supply a product that looks and behaves almost the same. It is made with fiberglass and aluminum coating. They typically use it to protect wiring harness (hello) and such . This is what I have done and to install a 83" aux. cooling fan on my 77' plus a hood blanket,battery,and AFM wraps, keep the old stuff working and protetcted. cheers Dave

I noticed in the FSM (factory service manual) that it shows using all metal tubing on the high pressure side, to be "butted end to end" with just Fi hose overlapping the splitline between the the tubing. This is a much stronger line than just FI hose only and does not allow hose fluctuation from pressure variances.

True that make certain timing is correct for an OEM setup, mine was doing that also until I timed it, before I tuned it up and retimed it ...no bueno ..backfiring.

So Cal is very dry...low rust gents.New Mexico & Arizona is too hot but good also. I understand that if you want a non rusty body.

Found somthing interesting on this system and more on the fuel dampner...@ the AustraliaK-Jetronic site plan. THE FUEL ACCUMULATOR, OR BETTER KNOWN IN AUSTRALIA AS FUEL DAMPER, is located just after the fuel pump. So it's location is between the fuel pump and fuel filter. All K-JETRONIC systems must have this very important component fitted into the fuel supply line. The housing of the fuel accumulator is split into two parts, the same as the fuel distributor. The difference is that the top part houses a very heavy compression spring, and as well, it has a safety fuel bleed outlet or, in other words, atmospheric discharge opening. The joining point to the bottom half is a metal folding lip and houses a heavy duty diaphragm. The bottom part has internally a metal fuel deflection plate, where the inlet fuel line is connected to a metric fitting. The fuel outlet is then taken off from any part of the bottom housing, as well from a 14 mm metric fitting. The exact location of the fuel accumulator is as close as possible to the outlet of the fuel pressure pump, or main pump. This will inhibit any fuel pressure noises from the fuel pump. As we have learned, the relationship between fuel flow and fuel pressure, are constantly changing. The fuel accumulator will now assist in keeping the pressure and flow in the fuel distributor bottom half always the same. The fuel accumulator now has the ability to take into itself the reserve pressure and flow from the fuel pump. Due to the long fuel line to the engine bay, known as fuel pipe flow friction and the system pressure regulator valve in the fuel distributor head, this keeps the diaphragm of the fuel accumulator compressed and therefore stores more fuel while the pump is running. By acceleration, some of the fuel FLOW AND PRESSURE will enter the top half of the fuel distributor, which can only go ONE WAY to be discharged by the injectors. The diaphragm in the fuel accumulator can now compensate for the fuel diversion to the injectors, or fuel diversion via the system pressure relief valve. The fuel accumulator also plays the role of controlling the fuel flow ' back up '. Either to the injectors or via the system pressure valve.

I cleaned the fuel pump strainer and added a clear,inline fram fillter. The system was clean with no debris present. Unless the return hose is clamped the pressure drops to below 30 psi and car runs really rough, clamp it off and I have up to 60 psi on fuel rail. I think I will go with another fuel pressure regulator (adjustable) maybe the new one I bought from the old shop on a sunday had been on the shelf forever and no good? but first really check the vacumme from the air intake, I have been over that thing looking for leaks every which way but as you know there are many places to look. I suppose one way is to place a vacumme gauge at the FPR Valve intake port and measure then compare to that of the FSM? I have not studied this in the manual yet and I am not too familiar with a vacumme system except to know one does not want leaks!!(which I should not have now) after all the lines have been replaced,clamped, tighted,sprayed you name it! Also I already made certain that the fitting was unrestricted with a pipe cleaner and there was not any fuel present. High Ho High Ho off to fix the problem when my Gfriend is not looking I go!! pls wipe off your cyrstal balls on this one, does it sound familiar!

Thanks Stephen,David all great ideas that I will heed to. Where did I get the notion that the Fuel dampner (snubber) was not required was not needed ?? () a post somewhere like this one. Yes fellows I'll be putting that back on now I am thinking perhaps of a bit friendlier location just before the fuel filter.Not noticable there either. What do you think? *My fuel rail arrived today from Juan on Ebay and I got a nice little 20 buc,0-60 psi marshall gauge for it. *I will be pinching off the fuel tank line and cleaning the pump inlet screen and installing a nice see through line filter to monitor the tank cleanliness from here on out.I should probably just throw in a new pump and tidy the wiring....hhhmmm 200 bones. Second thought Ill send that in for rebuild I've seen somewhere that a guy does this and has much expertise and we will see what happens after that. Can't thank you fellows enough Dave

Hey Gent's If I might just say thank you all for your valuable experience,patience,and tenacity. I recently bought a (weekend warrior)a 77' 280Z in brea Ca. The guy kept it in really good OEM condition but did not drive it much in the 30 years he owned it. Now I am down to the issue posted in this thread, unfortunately the new fuel rail I ordered on Ebay has not yet arrived to gauge the pressure and return line scenario to collect data.I am just resting from doing all the front end bushings,struts,etc but when I find the problem(w/your help I will post here) At this point I will review the injector hoses to ensure they are FI variety and the FPR it was not Nippon but some local US mfg so I am suspicious. At present it runs darn good but fades or lacks the "power band" when shifting at 3500- 4000 rpm I think perhaps some adjustments may need optimized EFI tuneup butalso related to this, as soon as I release the return clamp it runs like $^!#! FYI- My fuel problem through me off because it simulated an almost "cold start condition" it would barely idle until it reached normal temperature and then it would occassionally cough in the intake manifold I retimed it and found that went away when I clamped the return line- idle picked up,engine smoothed out.I think the injectors are fine they are also new plus the fuel and vacumme systems have no leaks- *all have been replaced recently I must have tightened and stared at those$#%@$% 30 times! *Some things the original owner had done to sell and smog the rest I figured what the hell it was a thrty year old car so just did it. But I did replace the: FPR filter Cold start valve Thermistime switch *coolant switch wiring connectors air Press. reg. (I had an extra one from my 80 Z that was stolen years ago) None of which helped the issue above. I removed the fuel pressure snubber device near the Fuel pump and found no difference, somewhere I read that with modern fuel pumps it is no longer required hence the reason it is not found after 1977. Also the Original owner stated that he changed the pump back in 97' w/oem. Sheer determination wll prevail Dave

It all went good, but unless you want to grind down all the speed bumps in your community I say set the new spring perch supports and lock rings flush to the top of the threaded standoffs. The old struts and coils looked good ;but worked bad these should be nice with the KYB struts and bushing kit that I installed. Later I'll do the rear,resting now because the new clutch slave cylinder wont bleed even with a power bleeder- probably will be fine after a nap. All kidding aside it was pretty labor intensive the first time around but saved alot of bucks and bragging rights (anyone can pay a mechanic to do it) Dave

Well fellows here is my 2 cents. I must be the 1977 280z experiment here without knowing much I had bought these off EBAY. Fortunatly enough 4 me they appear to be alright (thanks cosmo) with very light if any modification. At first glance you want to cut at the top of the old oem bearing support and slide that onto the aluminum top that Cosmo supplied. So as far as the installation being "as advertised"? 4 me it is going well for the type of job we are talking about. It is my first time tackling suspension.(gotta man up sometime) FYI-The illustrations in the cosmo manual showed more of a shock or rear type application but I surfed the net and found couple examples. However we will see AFTER I load it all up and test drive, which will be a bit later. cURRENTLY I am replacing the bushings,brake pad,boots ...all that. ..................................................................................................... Thank god I am lucky lucky this was operated in Brea California who had an anal owner (like me now) for the last thirty years, I am enjoying going through this car with the factory manual. Mods so far: valve job New 2 1/2 ehaust and high flow converter (tried to keep it looking stock with OEM manifold and large stock muffler for quietness) still it growls all std. services done injectors & replaced clutch replaced Radiator/thermostat Thermistine switch,wtr cool switch

1977 OEM 280z: thirty some years one owner. No oxygen sensor on mine. And thats a fact jack

Yes I see that this requires more impartial testing that some mentally challenged "nay sayers" (not saying I agree or disagree) are not willing to try & would rather codemn all those who do from the vantage point of thier arm chairs. () good analysis over time should reveal any merits of this acetone use then we can thank all those for sharing the findings of thier hard work. To the nay sayer I say thanks for keeping things honest. To the acetone tryers - don't get it on your paint. stay kewl Zsters