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WaiDai

Car not starting 1983 280zx turbo

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thanks for reply cgsheen!

yes i checked plugs and they are in normal condition.

UPDATE!

i started the car today and it ran fine. soo its not a fuel or any of that kind of issue. i let it run and warm up. rpm ran nicely then droooooped slowly... till it finally was at like 600 rpm.. i was sure at this point its something related to that.. soo i shut off the car already expecting that it wont start. and boom it didnt. soo i checked timing and it is fine. fuel is fine.. but what can this be? it just keeps dropping. of course i can just hold in the throttle but that wouldnt be good.. soo it seems i have to wait a few days before i can start it each time.. any clue? O2 sensor? iono... but it seems once i wait a few days itll start again.. and this is a few days with the negative off of the battery (no power) soo... any idea? i figure the ecu wipes itself either immediately on these cars.. or withing a few hours.. but why must i wait a couple days? help me figure this out! thanks again!

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There is nothing to be "wiped" on the ECU so that is not it. The symptoms sound like there is gunk that clogs your fuel pickup which then settles out after some time so that you can start the car again. I know you measured fuel pressure, but did you measure it while the engine is struggling/dying? That is necessary to rule out the fuel problem. You could also run your fuel pickup and return hoses to a gas can and see if that makes a difference.

 

The other thing that seems weird is that your timing seems to be changing on the fly. Maybe your crank angle sensor (in the distributor) is failing as it heats up. If you have access to an oscilloscope you can probe the contacts at the ECU connector (check FSM for which ones) and verify that you have a pulsed signal when the engine is turning over.

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There is nothing to be "wiped" on the ECU so that is not it. The symptoms sound like there is gunk that clogs your fuel pickup which then settles out after some time so that you can start the car again. I know you measured fuel pressure, but did you measure it while the engine is struggling/dying? That is necessary to rule out the fuel problem. You could also run your fuel pickup and return hoses to a gas can and see if that makes a difference.

 

The other thing that seems weird is that your timing seems to be changing on the fly. Maybe your crank angle sensor (in the distributor) is failing as it heats up. If you have access to an oscilloscope you can probe the contacts at the ECU connector (check FSM for which ones) and verify that you have a pulsed signal when the engine is turning over.

 

would a bad crank angle sensor still generate spark? i figure one that is failing due to heat may prob just cause an adjusted spark and throw off timing. thanks for the reply. i think there probably was gunk clogging the fuel system. i dont have access to a pressure reader at the moment but by how spontaneous the non starting issue is. it seems like it may be right, will clean out the tank when i get the chance. thanks DCZ

 

Update : got car to start again.. shut it off while it was still cold (1k rpm range) tried to start again.. wouldnt start. checked the plugs.. coated in black (fuel). i dont know if this can also be related to a bad crank angle sensor. or if i have a vac leak somewhere.. but at the same time.. i figure even with a vac leak.. my car should still start and run.. but just rough. i cleaned the plugs with brakecleaner and a lighter as explained to me by my brother (mechanic for honda for many years...) and cheked for spark, still got plenty. maybe there is a relation to all this? or just separate problems..

 

update (july 17th) started the car. for like 5 seconds.. then turn it off.. tried to start again.. it didnt go.. hmm help please?

Edited by WaiDai

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replaced o2 sensor and crank positioning sensor..

 

Problem.

car only starts once .. no matter how long i let it run.. even if it were for a brief second.. the car doesnt start up a second time. usually have to wait about a day for it to start again... veryyyy weird.. its not a flooded system either.. and spark is still there.. sommmeeeonnnnee helllllpp mee!!!

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get a can of starting fluid. use it see if you can get a second start out of it. If so then pretty likely you have a fuel delivery issue. need fuel, fire and air to run. load check your battery and be sure your cables are clean, tight and free of corrosion on both ends. Z's don't like low voltage. you can get the amps to crank but not the voltage to run the electrics (ask my wife about the time I took her for a ride and we couldn't get off the ferry). Get a can of Deoxit by CAIG. clean the connectors for AFM, TPS and ECU with it. you've done so many other things time to be looking at very basic stuff. You say you measured fuel pressure after the regulator which is the totally wrong place. the fuel comes from the pump to the filter then to the fuel ring and then to to the FPR. your gage needs to go between the filter and the fuel ring. You really need to understand the fuel system. try downloading the fsm from xenon and READING IT.

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get a can of starting fluid. use it see if you can get a second start out of it. If so then pretty likely you have a fuel delivery issue. need fuel, fire and air to run. load check your battery and be sure your cables are clean, tight and free of corrosion on both ends. Z's don't like low voltage. you can get the amps to crank but not the voltage to run the electrics (ask my wife about the time I took her for a ride and we couldn't get off the ferry). Get a can of Deoxit by CAIG. clean the connectors for AFM, TPS and ECU with it. you've done so many other things time to be looking at very basic stuff. You say you measured fuel pressure after the regulator which is the totally wrong place. the fuel comes from the pump to the filter then to the fuel ring and then to to the FPR. your gage needs to go between the filter and the fuel ring. You really need to understand the fuel system. try downloading the fsm from xenon and READING IT.

i measured both areas for fuel pressure to detect whether if the fpr was working also.. i figured that if the fpr pumped enough pressure.. then that is just before the injectors sooo yea... ill try out the CAIG stuff, never heard of it. i already tried starting fluid. that didnt work, same response. i checked the battery with my jumper tool and bars are still nice and green. i truly understand the fuel system. i just took extra time to check fuel pressure in other locations other then just whats given on the fsm. i spent alot of time reading it.. and i mean a WHOLE lot. its been a long year. so most definitely i paid attention to the fsm. the caig idea ill try though. the issue seems very weird. i cant even google its symptoms.

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You mentioned lots of blue smoke with a fuel rich smell, in the first post. Have you pulled a plug or two right after it won't start? It sounds like it's flooding, and it takes a day to dry out.

 

Check your CHTS, if it's not working or disconnected, you'll end up with too much fuel.

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You mentioned lots of blue smoke with a fuel rich smell, in the first post. Have you pulled a plug or two right after it won't start? It sounds like it's flooding, and it takes a day to dry out.

 

Check your CHTS, if it's not working or disconnected, you'll end up with too much fuel.

That has been fixed. it wasnt blue. it was just super super super rich fuel. it got fixed by replacing the afm. the only issue left is the car only starts once. a day ish (havent bothered counting hours, but its longer then 3 hrs). i pulled the plugs and cleaned them. so plugs are giving excellent spark. i wondered if it was flooding too..so i started it after like 3 days and let it run for only like 2 seconds. and it wouldnt start again.. it literrally only starts once =[

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You should check the fuel pressure as it struggles and dies.

Also check the vacuum reading as well.

You'll find a clue within one of those readings.

A vacuum gauge is very helpful.

 

Also, you said it finally worked after you switched the maf.

 

It reminded me of a situation where my car wouldn't start, or it would start and die fast, or it would drive for 15 minutes and die suddenly.

I kept trying to restart but it kept flooding. thought it was alot of things alternator/ starter/ ign/ fuel.

 

But i had spark/fuel/air. switched alot of things...

Ended up being a loose maf vacuum. when it was close to the vacuum line, it worked, but when a bump or overtime/vibrations, it moved apart and the engine died.

Check all your vacuum lines if you haven't. make sure theres no leak or anything easy. They have a spray you can use as well. Or do a smoke test where you blow smoke into a line when the car is on and see if it pops out anywhere.

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Sorry to hear that you are having so much trouble with getting it started but it seems to me you are picking and choosing what advice to take and what to disregard. First get rid of the fuel problem and run a remote gas can with pump and filter. (I am betting this will solve the problem) Then check your timing and vacuum lines with it running. If that wont solve the problem then you have a faulty connection somewhere check grounds and connectors. Hope you are taking this with a grain of salt I am not trying to cause any strife.

 

Happy wrenching.

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its been a LONNNNG journey... but finally figured it out. i noticed today as the car warmed up its idle gets lower and becomes too low till it dies.. also the air fuel ratio goes bad as its warming up.. then boom it dies and doesnt start up.. soo i figured it has to be the chts. i took a part i ordered that apparently isnt for my car via rock auto (coolant temp sensor) and stuck it where the chts is. i read post about its functions and that its similar THOUGH its not something i should leave on in the long run due to its ideal usage is for liquid heat and not i gues metal contact heat? anywho i stuck it in its place. started car... and was able to start any time i wanted.. i warmed the car up then it warmed and lived among 2-3 bars but usually around 3 on the rpm.. and today.. i finally drove my car around the block =] was able to park and drive it again... life is great! but now to find another 280zx to compare ideal stock performance... since i dont know whether if my car is struggling or if that's just how it is. either way its fun to drive! =] i am loving my Z now..

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