280z from 1977: startup and idle problem | The Z Club of Great Britain

280z from 1977: startup and idle problem

Discussion in 'S30 (240Z,260Z,280Z) Engine' started by cpresslmayer, Sep 17, 2017.

  1. cpresslmayer

    cpresslmayer New Forum User

    Hi z-community,
    I have some trouble with my 280z engine - it is starting very hard - needs a lot attempts and then runs very weak - after getting warm the engine run is getting better, but takes gas very bad - nearly stopping when cold - and misfiring often ...

    With the following link you could experience the behavior:
    ... the engine run half a hour before, so was not too cold. without this it would need 8-10 start attempts until coming to live ...

    What did I try hitherto:
    1. as the fuel pump that was mounted (also not original) whas very loud - I ordered an aftermarket pump from zcardepot.com (https://zcardepot.com/electric-fuel-pump-fuel-injection-280z-280zx.html) and mounted this ... it also is getting very loud when the engine is running :(
    2. i checked the spark plugs - exchanged them to the originally recommended NGKs - and adjusted the distance to 1,1mm als recommended in the service manual
    3. checked ignation cables and connectors - all looks normal
    4. checked ignation distributor - is new and looks normal - adjusted the ignition moment towards preignation - so the engine runs a bit smoother
    5. removed the from the previous owner in Phoenix mounted open sports air filter and mounted the repainted original filter box with a new K&N filter

    Would should I do next to optimize the engine run?

    Does anybody have the some experience and a solution form me?

    I am very thankful for every hint and help!

    thank you, Chris from Austria
  2. A2Z

    A2Z Forum User


    With the 280Z engine, which is fuel injected, try posting up the problem on the US Classic Z car website:


    They will be more familiar with any issues associated with the 280Z, which wasn't officially sold in Europe.
  3. SeanDezart

    SeanDezart Official Trader

    Frequently, the air temperature sender has rusted away - open up the pipework from inlet manifold towards the radiator and check it out.
  4. Mark N

    Mark N
    Z Club Member

    It looks like some components have been deleted/substituted (EGR and air regulator)!
    Might be worth checking this has been done properly.
    It looks like some kind of valve where the air regulator should be.
  5. Huw

    Z Club Member

    Could also be a cold start injector issue. But as above You do apear to be missing some components. This manual is worth getting as gives I depth info into the fuel injection system.

  6. cpresslmayer

    cpresslmayer New Forum User

    in between did organize the original manual in german from a local workshop - did also order the cold start injector and will try to reapply the air regulator the former owner had removed in phoenix - but do not manage to get a new fuel pump regulator ... :(
  7. vipergts

    Z Club Member

    All that US emissions **** was chucking in the bin.

    Chuck some carbs on it and skim the head..
  8. cpresslmayer

    cpresslmayer New Forum User

    You are right - the previous owner removed the EGR and air regulator - told me he wanted to optimize the performance and air regulator is not necessary in his surrounding in Phoenix ...

    ... I will try to exchange the critical elements for a continuous fuel and air supply (fuel filter, fuel damper, fuel pressure regulator and air regulator) - already exchanged the open air filter with the original air box and a k&n filter, the spark plugs with recommended ones and optimized the ignation timing - but with minor positive results ... and check the fuel pressure with a separate gauge

    ... next step is to clean or exchange the injectors if necessary ...

  9. cpresslmayer

    cpresslmayer New Forum User

    a and also organized a new cold start injector
  10. cpresslmayer

    cpresslmayer New Forum User

    achieved status quo after various adaptions over the last weeks ...

    Hi there, after weeks of work with different trials and part exchanges I achieved the following result. Sounds and feels definitely a lot better from my point of view!


    I did the following things:
    1) replaced plugs (with 1.1mm gap as manual shows)
    2) cleaned and replaced fuel pipes
    3) replaced fuel pump
    4) replaced fuel filter (in engine bay before fuel reaches injectors)
    5) placed extra fuel filter before fuel pump directly after tank to visualize tank / fuel condition
    6) placed pressure damper before fuel pump (missed this part before)
    7) exchanged fuel pressure regulator (in engine bay - did find a similar Bosch part in Puerto Rico)
    8) placed (the original) air regulator (former owner did remove it)
    9) replaced injectors (former once where in parts original and some had already been replaced earlier - did find reworked ones at rockauto)
    10) adjusted ignition timing to best possible engine run

    Currently the following activities are still planned to do with the engine:
    - exchange fuel pipe from the fuel pump in the back to the fuel filter in the engine bay to apply a steel flex mantled pipe - current one is pure rubber
    - exchange fuel pump once again - the after market piece is getting very loud ... ... hope the second after market pump is doing a better job ...

    In parallel I am working on the under carriage (removing original protection fluid, have to do some welding in of steel sheets and then applying new layer of under body protection), reworking of the drive line (incl. bushings) and further more ...

    ... and in spring repainting of the whole body is planned
  11. jonbills

    Z Club Member

    Well done Chris, that sounds pretty good. Have you any pics of where it needs welding?
  12. cpresslmayer

    cpresslmayer New Forum User

    as in my posting about full underfloor panels stated:
    ... one of the former owners did correct rotted spots without welding - only riverted some thin steel sheets ...
    ... the passender side has 2 major and and the side towards the wheel housing is fully replaced only with a riverted sheet
    ... at the drivers side only 3 minor spots (2 holes where normally rubber plugs should be applied) had been riverted and 2 further unsolved areas did I find

    https://www.dropbox.com/s/wqj0081o45... 41.jpg?dl=0
    https://www.dropbox.com/s/1kuo8n8mhl... 17.jpg?dl=0

    do you think cutting out rectangular forms and welding in new sheets would be enough and reduce effort?

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