Results 1 to 7 of 7

Thread: 75 280z bucking, lack of power...

  1. #1
    Senior Member
    Join Date
    Nov 2008
    Location
    Orange County
    Posts
    248

    75 280z bucking, lack of power...

    I'm at my wits end with this thing I'm probably just going to have a shop look at it, because if I keep working on it and having the same issue, I'll get angry and sell it.

    So, 280z, stock l28e... A few months ago I'd been having an issue with it bucking, going on and off power and clunking along, and having the idle go crazy, between 500 and 2000 and back and forth again. The engine lacked power, and when I took my foot off the gas, about three seconds later the car would sort of clunk, and I'd occasionally smell gas.

    I replaced every vacuum tube (a few were broken) in the engine compartment and a bunch of fuel lines on the rail, replaced the clamps... I had an issue with difficult starting that I rectified by finding another vacuum tube which was broken, and replacing that.

    ...so the car ran PERFECTLY for about a month, and now... I'm back to all the same problems as before, including the gas smell. I've checked all the fuel lines, re-checked all the vacuum lines, and I just feel really futile right now...

    ...My significant other and I just bought a nice z31, but until my car is sorted out, I'm in no mood to brag about it/post pics.

    Any ideas as to what this could possibly be? Bad ignition? Bad vacuum advance? Bad fuel pump/pressure regulator? Or, its off to try either Shinzo or Mike's z Shop. It just kills me that while I can find no difference in the engine bay between now and last week, when it was perfect, I have the exact same problem as previously.

  2. #2
    Senior Member
    Join Date
    Feb 2007
    Location
    Napa Ca
    Posts
    209
    If your car had carbs, I'd say you have a bent throttle shaft and the butterflies aren't closing. Since I'm pretty sure your car has FI, I'd guess a bad injector.

    Will

  3. #3
    Administrator john's Avatar
    Join Date
    Oct 2007
    Location
    Arlington, TX, USA
    Posts
    5,530
    Have you checked the big rubber tube between the throttle body and airflow meter?

  4. #4
    Junior Member
    Join Date
    Dec 2009
    Location
    dallas, tx
    Posts
    24
    not the problem mr roper.....the issue will be your CHTS, cyl head temp sensor, its the pricey little bugger on the front of the thermostat by your $15 water temp sensor.

    That should fix your issue, but its probably best you check the wiring going to it and find one at the junkyard or swap one off of a good running car, if you decide to buy one new (around 150-200 last i checked). Hope that helps as ive seen this and actually had it happen to me once. Also sign up over on hybridz.org....alot of info on that site but please SEARCH and you will find almost anything you could possibly want to ask.

  5. #5
    Senior Member
    Join Date
    Nov 2008
    Location
    Orange County
    Posts
    248
    Thanks for the advice all, I just have to step back from the issue for a while, whew, I take my car too personally.

    It's hard for me to feel like wasting ~$150 replacing sensors blindly if I don't really know how to test if they're bad in the first place, so I'm pretty ready to leave that up to the care of professionals and their judgement :P Ugh.

    I am 90% sure the fuel injector o-rings might be somewhat gone... A few of them seem to budge/wiggle with little effort. I might at least try doing that myself first, and that would account for intermittently smelling gas...

  6. #6
    Junior Member
    Join Date
    Jun 2008
    Location
    NorCal
    Posts
    17
    Check your dist. cap for cracks.

  7. #7
    Senior Member
    Join Date
    Aug 2009
    Location
    Los Angeles, CA
    Posts
    182
    the chts is a good place to check since the old efi sysstems just had 4 sensors to manage the fule ..1 the t.p.s. 2 a.f.m. 3 c.h.t.s and 4 crank signal ... the chts is a big part cuz if it gets unpluged the car will stutter and die it also dicides how much fule it will use at cold and hot operations .. to check it or how to check it you can look in to hains manuls from 77 810 datsun and efi 280zx. they have a boiling water test ...

Similar Threads

  1. Power seatbelt delete?
    By dan on a plane in forum Resto Tips, Wheels & Other Goodies
    Replies: 0
    Last Post: 09-09-2012, 08:58 PM
  2. 2M/4M power comparisons
    By palatine in forum Toyota Garage
    Replies: 3
    Last Post: 06-19-2012, 04:25 AM
  3. Replies: 20
    Last Post: 05-30-2011, 05:02 AM
  4. No power in car need help!!
    By syco781 in forum Toyota Garage
    Replies: 12
    Last Post: 11-28-2010, 11:27 PM
  5. ke70 more power!! please help!!
    By j.c grime in forum Toyota Garage
    Replies: 1
    Last Post: 03-11-2010, 06:55 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •