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cclxxxz

1978 280z Engine Sputtering/Bogging ..

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Hello Ladies and Gents!

 

New here.. been lurking around reading here and there.. thank you for all the tips and advices!

 

A little background about me.. i have a very basic to moderate understanding when it comes to automotive work.. ive worked and own a 1986 toyota corolla gts for over 10 years .. and this 280z is my first Nissan platform..

 

Its a father and son project .. we picked up this 280z in san francisco .. january 18th of this year.. so we trailered the car back to Irvine california.. 

 

first day.. drained the fuel and inspected the fuel and its clean so i decided not to drop the tank..  check out the dipstick and the engine oil still looks good.. radiator green coolant was full to the top and was clean.. 

 

so i decided that its safe to try and start the car.. and it started right up.. i let it run until its in normal operating temp.. took the car same day to get smog and pass smog (legally) .. this was a good 100 miles back and forth..

 

drove the car for about a week from home to work.. (25 miles a day) until after one week.. after work.. the car wouldnt start.. it cranks.. so i decided to check the fuse block.. check the spark plug wires.. so the car started right up but idling rough and when i step on the gas it dies.. i decided to drive and crawl the car home.. if i dont gas too much the car is fine.. but anything more than that sweet spot the car bogs down.. and dies..

 

anyways..fast forward what was done so far..  i change the fuel filter, fusible links, all the fuses.. cleaned all of my grounds.. 

 

noticed everytime i touch and wiggle the water temp sensor connector the car idles and revs fine.. until after a day.. the same problem happened again.. so i decided to remove the water temp sensor .. inspected it and cleaned it.. and installed it back (lost a little bit of coolant) upon inspecting how much coolant left inside my radiator i noticed white gunk all around the fins.. so i would assume its throughout the whole radiator.. anyways i started the car and its idling and revving fine now .. drove it around for about an hour .. got back home and its still good..

 

this morning on my way to work the car just bogged down while i was in 5th gear cruising at 65mph and died.. started the car again and it started right up and made it to work.. 

 

my plan is to buy a new water temp sensor, water temp sensor connector, thermostat and a new radiator .. 

 

have any of you guys experience this problem before? am i on the right track? could it be something else?

 

excuse this long post .. my aologies in advance.. 

 

 

 

 

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3 hours ago, cclxxxz said:

we picked up this 280z in san francisco .. january 18th of this year.. so we trailered the car back to Irvine california.. 

 

so i decided that its safe to try and start the car.. and it started right up.. i let it run until its in normal operating temp.. took the car same day to get smog and pass smog (legally) .. this was a good 100 miles back and forth..

 

anyways i started the car and its idling and revving fine now .. drove it around for about an hour .. got back home and its still good..

 

this morning on my way to work the car just bogged down while i was in 5th gear cruising at 65mph and died.. started the car again and it started right up and made it to work.. 

 

my plan is to buy a new water temp sensor, water temp sensor connector, thermostat and a new radiator .. 

 

Looks like you have a new problem.  The diagnosis on the first and the fix was good.  Not sure that you need those new parts, cleaning connections is usually good enough.  Bad connections are a major problem on the old Z's and ZX's.  Poor sealing and weak metal.

 

Did you notice what the tachometer needle did when it died?  If the needle still followed engine RPM as you coasted to the side of the road that means you still had spark.  If the needle dropped to zero even though the key was on and engine turning that means you probably lost spark.

 

How long was the car sitting before and why did they park it?  Might be that the ignition module, the "match box" on the side of the distributor is going bad. (Edit - screwed up here.  1978 doesn't have the match box.)  Or the stator magnets in the distributor .  Super common problems.  The module heats up, engine dies, cools off, engine starts.

 

 

Short - check the inside of the distributor.  Check the teeth of the six pointed rotor for wear.  The bushings go bad and they move and rub.  Clean the matchbox connections.  Check the breaker plate bearings for rust.  Most old ZX distributors have died or are about to die.

 

Since you passed smog and it runs well don't go too crazy.

Edited by NewZed

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37 minutes ago, NewZed said:

 

Looks like you have a new problem.  The diagnosis on the first and the fix was good.  Not sure that you need those new parts, cleaning connections is usually good enough.  Bad connections are a major problem on the old Z's and ZX's.  Poor sealing and weak metal.

 

Did you notice what the tachometer needle did when it died?  If the needle still followed engine RPM as you coasted to the side of the road that means you still had spark.  If the needle dropped to zero even though the key was on and engine turning that means you probably lost spark.

 

How long was the car sitting before and why did they park it?  Might be that the ignition module, the "match box" on the side of the distributor is going bad.  Or the stator magnets in the distributor .  Super common problems.  The module heats up, engine dies, cools off, engine starts.

 

 

Short - check the inside of the distributor.  Check the teeth of the six pointed rotor for wear.  The bushings go bad and they move and rub.  Clean the matchbox connections.  Check the breaker plate bearings for rust.  Most old ZX distributors have died or are about to die.

 

Since you passed smog and it runs well don't go too crazy.

 

Thank you! 

 

actually my tachometer never work it was not functioning prior to buying the car and havent got around fixing it.

 

previous owner stated that it has been sitting for atleast 1-2 years and they never had time to do anything due to too many projects going on at the same time.. until they lost interest and needed space ..  

 

so yes the key was on .. because of car and wind noise not exactly sure if the engine died .. i wouldnt doubt it didnt.. but as soon as i pulled over i started the car right away and it started and it drove fine for another 20 mins and no problem.. i guess what im trying to say is that the car didnt really cool off so would that still point to the “match box” ?

 

i check if i had spark from my ignition coil and yes i do.. i havent inspected my cap and rotors just yet..

 

 

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51 minutes ago, NewZed said:

 

great write ups and websites! will definitely come in handy! thank you very much!

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15 minutes ago, cclxxxz said:

. i guess what im trying to say is that the car didnt really cool off so would that still point to the “match box” ?

 

 

It could.  They'll cool off pretty quickly.  They're exposed and attached to the distributor.  It's heat generated from inside the module that overheats them.  Sometimes as they're going bad they'll only die at higher RPM when there's a lot of current flowing. 

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2 minutes ago, NewZed said:

 

It could.  They'll cool off pretty quickly.  They're exposed and attached to the distributor.  It's heat generated from inside the module that overheats them.  Sometimes as they're going bad they'll only die at higher RPM when there's a lot of current flowing. 

 

i mean it was literally about 10-20secs when the car died until i made it to the side of the freeway.. so i doubt it cooled off that fast.. 

 

ill inspect all of the parts that you mentioned and go from there..

 

did a quick search and that matchbox is pretty expensive and not available in most Z parts stores online . can it be rebuilt/cleaned up? 

 

thanks!

 

 

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30 minutes ago, cclxxxz said:

 

i mean it was literally about 10-20secs when the car died until i made it to the side of the freeway.. so i doubt it cooled off that fast.. 

 

 

You've gained expertise amazingly rapidly.  You should have it solved soon.  Good luck.

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8 minutes ago, NewZed said:

 

You've gained expertise amazingly rapidly.  You should have it solved soon.  Good luck.

 

NewZed,

 

My fault I didnt mean to sound like I knew exactly what was going on.. more of just trying to brainstorm  to see if there should be any other problem i should look into.. thank you for your time and i really appreciate the tips and advice .. thanks!

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With these old EFI systems and just general wiring of the cars it pays to assume that anything could be the cause and check out all possibilities.  "It can't be that" has wasted a lot of time for many people.

 

If your tach worked you could just take it for some test drives and watch the needle.  The tach is connected to the ignition circuit and the EFI computer and might even be part of the problem.  Might be worthwhile to check the wiring to the tach.

 

Download the 280Z FSM. It's full of good test methods and wiring diagrams.

 

p.s. I screwed up and thought you had a ZX.  Your 1978 distributor doesn't have the match box unless somebody swapped one in.  They still go bad though.  MY 76 had the high RPM problem and would restart just fine right after stopping.

 

Edit p.s. #2 - the little"i"s and texting mode punctuation kind of irritated me, hence the tone.  It's common but still...  Carry on, good luck.

Edited by NewZed

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