Crazy477280Z

Talk about the ghost in the machine!!! I came out and reinstalled AFM because I took cover off last night to check fuel pump contact point, and it was clean and making good contact when flap closed, and every thing looked good when I opened flap. Potentiometer is making good contact and operates smoothly.[i bought it new two years ago.....] anyway, I could hear fuel pump operating, so I plugged solenoid wire up, and also connected a 12 volt tester light to outgoing end of #4 fusible link. It lit up fine and I left it hooked up so I could see if it lost power there when car died. It started right up, and ran for over half an hour wwwwwwhile I shook,twisted, and flexed every wire and wiring harness to try a..nd simulate condition...No dice...car kept running until Ishut it off. It started right back up so I timed it,and now Ime going to do FI tests again. Maybe it just had a cold and its all better now?? I sure wish it was that easy because now I have this problem that could pop up any time unless I fix it,and now how do I know when Ive actually fixed problem. Thats sure not going to leave me feeling too comfortable driving it when it could suddenly drop out from under me. Ime still going to trace down fuse link by battery just to check condition if nothing else. I will let you know what happens.

Yeah, that has alot of info that might prove useful. Thanks siteunseen!!

If it is there its buried in the middle of wiring harness,because all my wires on pos. side are wrapped to within 6 inches of batt. Doesnt seem like a good idea to cover a fusible link like that, but it looks stock to me. I will unwrap it tomorrow and see what I see. Is there any chance it might be under dash on passenger side where harness comes through firewall? I dont know if manufactors would put a fuse link on inside of car,but I sort of doubt it.

Both AAR and fuel pump lose power when EFI relay loses power. Ime thinking that it has something to do with power supply to EFIrelay.After car started,and then died, I replaced EFI relay with brand new one instantly,and was still at no start condition. I can let it sit for 5 or ten minutes,then turn key to start position with starter solenoid unwired,and still am able to hear fuel pump running. I can then start it up,and it runs very well but then just dies. I still have spark at coil though, so Ime thinking[and I might be wrong about this as electrical problems are my weak point] that the ignition portion of COMBO relay is still getting power while fuel injection side loses it due to bad,corroded,or weak connection. Is there a fusible link between battery and ignition switch,or between ignition switch and EFI combo relay? I dont want to have to hire an electrician for this as Ive never had to do that before. Ive worked on every car Ive owned for the last 34 years with help and advice from wherever I could get it.This one is very uncommon,and is beginning to mess with my head. No one seems to have had this particular problem before,so its a mixture of reasonable deductions and alot of testing wires for good connections and continuity I guess.I will post again if I can find something new or definitive as to problem.

I have narrowed problem down but I dont know whats causing it. Apparantly EFI combo switch[EFI and ignition switch] loses power. I unhooked solenoid energizing wire,and could hear fuel pump running with old EFI relay. I hooked solenoid back up,and it started right up. It ran for about 5 minutes,then died. I unhooked solenoid again and fuel pump was not working again. I instantly changed EFI combo relay,and still no fuel pump noise and no power back at fuel pump. On the safety cutoff at switch...Are you talking about oil pressure sending unit? And I will try hooking up fuel pump direct and see what happens.OOh, and my oil pressure sending unit is working fine while running.

I have found that ime getting no fuel because fuel pump is not working due to no power at pump.I will check air flow meter also just to make sure everything is working correctly.Ime going out to work on it in a bit.Will stay updated till solved. Thanks for tips!

I went through EFI tests today and got a couple of readings that were off. Water temp sensor resistance at 50 degrees was 2134- Fuel inj. relay should have continuity... I have a tone on my multimeter that sounds when continuity has been made. All I could get when test probe is on number 20 on ECU connecter,and neg. probe is to vehicle ground, was barely a chirp that cut off right away...on cold start system test, I got battery voltage instantly. No battery voltage at pin 34 for\at air regulator. Air flow meter resistance #2 should read continuity[small resistance]. I have it reading 185.2 ohms. I think that might be a little much for small resistance. Also air temp sensor resistance was 2476 at 50 d Anyway, even though I had just replaced EFI relay, it looks like I get the pleasure of doing it again as fuel pump now appears to not be working.I cant seem to find any kind of voltage at fuel pump and aux. air regulator are on the same circuit. Seeing as how I just replaced EFI relay,and water temp. sensor,and just cleaned my air reg,should I be thinking that something is causing these things to fail prematurly? Ive got a Bosch 332 514 120 combo relay coming in morning.95 bucks!!!!! Every thing electrical for Z cars is priced like they are gold.but I guess they areni or they would conduct better. I will fix and replace what I can, andlet you know where Ime at after Ime finished. Thanks to Rossi and Blue for your comments on possible fuel system problems.

I just replaced it when all this began. Then the coil, then converted to zx ignition with used E12-80 module,replaced that with new E12-80 module,now changed over to GM HEI ignition,,,,,and I still have same problem,only now it only runs for about 10 seconds. It will start up again after another 10 to 15 seconds.Ime going to start from square one again and see if I can figure this out. I will post my findings later, if anything new,butt what a pain in the rear area!!!

Well, I switched over to GM HEI . Car ran for 10 seconds, then died. Still getting good spark at coil. I am still running the 81 zx coil,because I really havent researched what coil would be best to run with the stock GM module.So Ime going to start back at beginning starting with EFI tests, then tracing and troubleshooting every wire in ignition series. Ive been tempted to pull my matchbox dizzy and coil out of my running 81 zx,and installing them in 77 just to see what happens. I just dont want to needlessly burn something up, if there could be something causing this. I still might do it if I cant find a problem anywhere else. I will see what happens tomorrow and post what I find. Ime going to find out what coil will work the best. I just read your post on condensors also Blue, and will be sure to check them. I cleaned out fuel tank last summer and also run two fuel filters, but a good tip anyway. If anyone could give me a good coil choice to run with a 77 280z dizzy,GM HEI module....please throw a post my way...I thank you greatly!

I will try your tips tomorrow.O Reillys is going to test module though how they can tell its bad when it doesnt begin to fail until after it heats up. Zed Head,did you mean ground wire coming from tach? I wouldnt think you would ground resistor,right?

I will try you tips tomorrow. Thanks Zed Head!!!

Well, after performing 280zx ignition upgrade on my 77 Z,I had thought problem was solved except for tach issue. Today I drove it for about 2 hours straight then parked it with no problems. I took it out half hour later ,and she began having same symptoms as before upgrade. I do have good spark coming from coil right after it dies and it will start after 1 or 2 minutes, but die again after 20 or 30 seconds. Tach also immediatly drops to 0 RPM like it has rock tied to end of tach needle. Could I have burned out module [new],allready,or could this indicate a different problem.I love these cars, but they sure suffer from some uncommon malfuncti

I did think about loose wire in vicinity of clutch pedal but tach didnt even quiver when I pulled,bent,and shook wires under dash.Ime starting to believe that when clutch pedal is pushed in the clutch disengages,and engine is freed up from drag,and then tach begins to want to work again.Bad tach? I dont know but with tach working for half a day,and then acting like this,it could very well be a possibility. Is there a way to test it besides hooking up to different Z car?

Two days ago I upgraded my ignition on my 77 280Z to a ZX ignition system using E12-80 module,ZX dizzy,ZX coil, and soldered all connections,and protected all with heat shrink tubing. My tach worked fine until this morning. When I started it, tach jumped to 1400 RPM. As car warmed up,tach dropped slowly until tach reached 1000 RPM,and then it dropped to 0. I can give car gas and tach will work as long as RPMs are above 1000. I can also push clutch in,and tach will act like its trying to work,but as soon as I let clutch back out, tach drops to 0. I should have mentioned that this is happening even while in nuetral. Has anybody that has done this upgrade ran into this problem,and maybe might have found a solution?

Does anyone have a link for installing a GM HEI module in place of E12-80 on 77 280z?

Its not too surprising it quits leaking after warm up due to expansion of head and block. Probably pinches head gasket tight enough that it doesnt leak when hot. I take it that you have no other symptoms...Pressure build up in radiator,or white steam cloud out of exhaust?

I looked up that link you posted on the modules Zed Head...yeah-nasty,but the info was golden.thanks again.

Thanks Zed Head. I will measure coil tomorrow and make decision from there. Todays been a pretty long one for me. Thanx for the help,and I will give back whenever I can.

I have one more question regarding the 280z to 280zx dizzy swap to bypass TIU. Should I switch to a zx coil or does it matter? It ran good,but I dont want to run chance of prematurly burning up 280z coil if I can help it,especially since it was new yesterday. Ithink I remember reading a thread that said you should run 280z and 280zx dizzys with thier respective coils.Does anyone know the truth behind this?

Color this one solved! Just got back from driving my 77 after bypassing TIU,and installing ZX dizzy.My favorite Z doesnt have to live in garage for a couple of weeks.I went ahead and just switched modules so I didnt have to deal with any unknowns. You were right Zed.the right one was an E12-80. Thank you for all the help and hopefully in future Ican help some of you out.Karma is a wonderful ideal!

Thanks for the advice. I have fuel injection bible,and ran through tests yesterday because I did have a warm up issue.That led me to replace water temp. switch and aux.air valve.I replaced fuel filters and then drove it.Same thing...tach instantly dropped to 0. then started up one minute later.7 times later,I pulled into driveway.YEP...Ignition unit.So I looked at link from Blue(THANK YOU-MUCH APPRECIATED)and thats the way Ime goingto go since I also own a 80 and a 81 ZX with alot of spare parts.Inow have another question...I have two ZX dizzys...one has the module on side with the two spade conneon top. The other one is the same except that it also has some sort of sensor plug on the side of module.My question is...Can I remove module with sensor conn.,and replace it with correct looking module?The dizzy that has correct module on it is pretty worn and vac. advance doesnt work.NO.-D6K8-02.The other dizzy with incorrect module...NO.-D6K81-01...is in great shape with working vac. advance. So what do ya think?

thanks for tips. I willl change filters as it has been a while but I dont think it is a fuel issue.Tach does drop instantly to 0 when it dies and it doesnt take long to start back up...In fact,it died when I was 3 blocks from home,and I was able to compression start it within a block of home.I had thought coil was going bad and failing after warming up due to how tach was acting when it died which was why I had replaced it. It still died after warmed up,and this time I heard EFI relay clickas it died so I replaced that. SAME THING.So Iwent through all connections I could find that were related to fuel,ign.,and spark. then I ran fuel injection tests through ECU,and replaced water temp sensor,and auxillary air valve,and now cold start system works right,but it still dies after warmed up. I will replace filters and see what that does,but Ime still suspicious of trans ign unit.Is there a way to test the ones on the 280z?OR IS THERE A WAY i can connect a matchbox dizzy to my 77 and bypass the one inside car?

Heres a confusing one,at least it is for me. I have a 77 Z that I drive daily. 4 days ago it died on me. It started up again after a couple of minutes,but died again a few minutes later.Long story shortened...In the last 4 days, I have replaced coil,EFI combo relay,and cleaned and checked every elec. connection I could find. I still have same problem. Car will idle indefinitly,but will only drive for about 15 minutes at best.and then dies. It will start again after a minute or so.Ime beginning to suspect that it might be the TIS on the passenger side behind blower motor. Any body have any ideas? I know those trans. ignition systems arent suppossed to go bad all that often,but I would like to know if this is feasible with these symptoms.