78 280z idle problem

[Captain Obvious]

I haven't dug into technical details, but for those of you who are already looking into it... Remember that it's a 78.

Might be different than what you are used to seeing.

[Jack Pearcy]

19 minutes ago, Captain Obvious said:

I haven't dug into technical details, but for those of you who are already looking into it... Remember that it's a 78.

Might be different than what you are used to seeing.

Yeah that’s what it feels like, all the diagrams don’t match up and it feels like I have different components

[Dave WM]

 

45 minutes ago, Captain Obvious said:

I haven't dug into technical details, but for those of you who are already looking into it... Remember that it's a 78.

Might be different than what you are used to seeing.

oops right CO. That single lead sensor kinda looks like a switch for a cooling fan.

[Zed Head]

It's kinda looking like you might have a ZX or Maxima engine, or head, in your 78 280Z.  They use a cylinder head temperature sensor in place of the water temperature sensor.  It does the same thing and has the same temperature profile.  Those engines also had several extra temperature switches on the T-stat housing.

Take a picture of your engine's serial number area, and the head ID area.  You'll know more about what you're working with.

[Zed Head]

16 hours ago, Jack Pearcy said:

. Also the clutch fork is about 4.75 inches or 120.65 mm from the front of the bell housing.

 

Edit - actually I can't tell what you're measuring.  I measure to the bolt head.

Edit 2 - it looks though, like your fork is bottomed out on the hole it sits in.  Can't go any farther.

This is at rest, no foot on pedal.

Edited July 14, 2019 by Zed Head

[gwri8]

Zed Head is correct. Apparently  you have a transplant in your engine bay.  Here is a shot of the thermostat housing from a 79-83 ZX engine.  Looks like yours from what I can tell.  That certainly changes which parts to order.

[Jack Pearcy]

3 hours ago, gwri8 said:

Zed Head is correct. Apparently  you have a transplant in your engine bay.  Here is a shot of the thermostat housing from a 79-83 ZX engine.  Looks like yours from what I can tell.  That certainly changes which parts to order.

Yes that’s exactly what mine looks like

[gwri8]

Now to figure what it connects to. Once you confirm which head and block you have, you'll need download the proper FSM for a ZX and figure out which EFI wiring harness is in your car since you have since you have a dangling connection on the sensor.   One for the 78 or 79?   I know you have a 78' but which month was it produced?  I don't have first hand knowledge of the ZX but I'm curious as when they started changing parts for the new model in the production.  Maybe someone here can answer.

[Jack Pearcy]

6 hours ago, gwri8 said:

Now to figure what it connects to. Once you confirm which head and block you have, you'll need download the proper FSM for a ZX and figure out which EFI wiring harness is in your car since you have since you have a dangling connection on the sensor.   One for the 78 or 79?   I know you have a 78' but which month was it produced?  I don't have first hand knowledge of the ZX but I'm curious as when they started changing parts for the new model in the production.  Maybe someone here can answer.

My z was made in December of 77

[Jack Pearcy]

I’m also still having clutch issues, I dropped the trans again and reinstalled my old pressure plate, but it still won’t disengage the clutch. From what I can tell the clutch fork is hitting the bell housing meaning it’s being fully engaged, that should have some effect on the clutch right? It acts the same trying to get it in gear with my foot on and off the clutch

[Zed Head]

2 hours ago, Jack Pearcy said:

 I dropped the trans again and reinstalled my old pressure plate, but it still won’t disengage the clutch.  From what I can tell the clutch fork is hitting the bell housing meaning it’s being fully engaged, that should have some effect on the clutch right? 

We've produced several threads describing the measurements you should take to be sure your parts will work correctly, before installing them.  92 mm.

Not clear what you mean by the fork is "hitting" the bell housing.  Also not clear which throwout bearing sleeve/collar you're using.  You put the old pressure plate in but did you use the old sleeve?  There are a bunch of bad combinations of sleeve and pressure plate out there.  Clutch problems are common with the Z's.

You're doing a lot of stuff but not providing much info to work with.  Numbers.  Good luck.

[Jack Pearcy]

8 hours ago, Zed Head said:

We've produced several threads describing the measurements you should take to be sure your parts will work correctly, before installing them.  92 mm.

Not clear what you mean by the fork is "hitting" the bell housing.  Also not clear which throwout bearing sleeve/collar you're using.  You put the old pressure plate in but did you use the old sleeve?  There are a bunch of bad combinations of sleeve and pressure plate out there.  Clutch problems are common with the Z's.

You're doing a lot of stuff but not providing much info to work with.  Numbers.  Good luck.

The pressure plates are definitely different in size, and here’s a video of what I’m talking about, you can hear the clutch fork bump the bell housing. Also I replaced the throwout bearing and I’m using the original sleeve and clutch fork. The throwout bearing I installed is identical to the one I removed