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Glliw

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About Glliw

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  • Map Location
    Sheboygan, WI
  • Occupation
    Mechanical Engineer

My Cars

  • About my Cars
    SOLD: Mostly Stock, mostly original '74 260z. Original 95,xxx mile L26, 280zx 5spd, header, '70 round top SUs, foam air filters, some kind of exhaust, repainted 10 years ago Dodge red.

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  1. I just ordered a car's worth of these last night to replace my crapped out stock ones. I'll post up on my experience after the fact. For $130 shipped even if they don't last that long I can't complain. He'll that's near the price of one corner for the better options out there.
  2. Glliw

    Hanging RPM

    That's a good point, Kurby. I think I'll buy an egr block off plate and rule that out entirely then. I haven't had a chance to look at it any this week and won't until the weekend most likely.
  3. Glliw

    Hanging RPM

    I will double verify this tomorrow, but I have done this already with no effect as I recall.
  4. Glliw

    Hanging RPM

    Wouldn't that show as a vacuum issue on the gauge that I just tested with though? I would have to be below -15 in. Hg to begin to think I had a strong enough vacuum leak to create this effect I think. That and the whole works fine at cold temps part pushes me away from thinking vacuum.
  5. Glliw

    Hanging RPM

    It sure does, but it also happens when my foot isn't on the brake so I don't see a correlation there. In the videos above, I am not on the brake at all. Just run it up in 2nd gear and put the clutch in. I just did the vacuum test. I tee'd in at the brake booster line, at the firewall mount to try and include as much of the system as possible. From my perspective, I look pretty solid from a vacuum stand point. It hold at -18in.Hq at idle with maybe a 1/4 to 1/2 in. Hg fluctuation towards positive values. When blipping the throttle, it spikes to 0-ish, and returns down to -20 and settles back in at -18, just as it should. If there are any vacuum leaks at all, they are very minute and I do not think they are a driving factor here. I also inspected the underside of the intake manifold. I did not see anything obvious under there.
  6. Glliw

    Hanging RPM

    It always is something simple. Only thing is that there are 30 simple things in the system. Thanks again for the help, I definitely appreciate it. How long roughly should it take the intake to leak down during yogurt cup testing? 5, 10, 30 seconds? I'll buy a cheapo vacuum gauge and a mirror here shortly and follow this write-up: http://www.atlanticz.ca/zclub/techtips/vacuum/
  7. Glliw

    Hanging RPM

    I would think the same except the issue isn't there at cold engine temps. Also, EGR is effectively non-existent since the vacuum source to it is blocked off via the BPT block off, unless a massive leak is at the gasket surface. I do not have a vacuum gauge handy. The a/c idle control is disconnected and can be seen as such in the pic above as I had the same thought. Doing so had no effect. A few days ago I did do the "yogurt cup test" by using a yogurt cup to block off the intake after the AFM, creating a closed system. I pulled off the brake booster hose and pressurized via that. During that, I could pressurize with my mouth to a point and could hear a leak, probably past the valves. It would hold the pressure for 5-10 seconds. I sprayed soapy water at each nipple connection on the intake manifold and did not see any bubbling. The AFM boot does not have any tears in it.
  8. Glliw

    Hanging RPM

    Thanks for the thoughts, Mark, as well as everyone else. Though i do not think that is it. While the 280z does come with a "rev cushion", that has long since been removed as that was the first item I thought to look at. To back up my statement on how the car performs when cold, please check out this video. The rpms act as one would think they should and return to idle in a reasonable period of time. Once the engine begins warming up, the issue will persist. I also popped the cover of the TPS and checked its function. I cleaned the contacts with a electric parts cleaner. Everything looked cherry in there though. Do you think one of the temp senders may be playing foul here? I didn't think any interact with the system like this, but with it only happening at warmed up and consistently then I don't know what else to think.
  9. Glliw

    Hanging RPM

    Seems to happen only when warm. I have not checked the AFM. Yes it has been an issue since Ive owned the car. I'm complaining now as I only drove it from purchase origin then to body shopwhere it sat all winter. That used to help. I cleaned up the space around the throttle plate and added the helper spring which helps it come down quicker initially but still slow at2.5k downward.
  10. Glliw

    Hanging RPM

    It did this before the deleting began.the deletes were part of troubleshooting.
  11. Glliw

    Hanging RPM

    Between left and center pin, resistance is infinite at closed throttle and goes to zero throughout the whole range. Between the center and right pins resistance Is zero at closed throttle and goes to infinite slightly off of closed and stays that way throughout the full range. Between left and right pins there is infinite resistance throughout the range except for a small window of approximately 5 degrees off of closed.
  12. Glliw

    Hanging RPM

    Yep, it is. I pulled the AFM boot off and watched it return. Comes to a shut nicely. When the engine is not fully warmed up, say, around 1/3 temp gauge and below, a throttle blip will result in a quick rev and return to idle. The problem is greatly pronounced once at operating temperature.
  13. Glliw

    Hanging RPM

    Here's an engine bay shot.
  14. Glliw

    Hanging RPM

    Yep, both the torsion spring and the linear spring are in place. I installed a secondary linear return spring to see if it was a worn spring issue but did not see to help.
  15. Glliw

    Hanging RPM

    I'll take one here in a bit. The car is in the first post. There isn't a mods list because there aren't any, except for the vaccum deletes whilst troubleshooting this unless you think the front air dam affected this.
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