loose Distributor CAP = Perfect idle

[dutchzcarguy]

8 hours ago, Zed Head said:

cylinder head temperature sensor (CHTS).

is'nt that a knock-sensor?  the temp one is on front of the engine?  or is a knock sensor to modern?  As it is a turbo i never had one so don't know ..  to me that one looks like a knocksensor..

If injector 6 makes no diff.. get a new one and/or measure the signal on it.. does it get a signal? a scope is these days affordable for everyone.. (look for a oscilloscope)

EDIT !!  No the knocksensor is sitting near the oilfilter left and above it..  IT IS A WATERTEMP sensor indeed.. (I saw this in my 1982 280zx turbo manual!  just now..) 

Edited November 23, 2020 by dutchzcarguy

[dutchzcarguy]

on pic 2 you have the oilpressure sensor.. get a new one they are leaking oil inside so there is were the oil comes from.. also the oilpress. meter does not tell the correct press. any longer (it's actually a combination sensor 1 contact is a on/off for your red oilpressure control light (in your meter!) and the other contact is for your gauge.)

[ira]

i could swear i uploaded some stuff last night.  

couple of short videos showing car idle after 15min warm up starting to show blimps and missing.  Then cap was raised, car ran for 2 hours almost w no signs of any idle issues.

unplugging inj 6 made no diff, while unplugging others clearly showed a difference.

there is an incredible amount of exhaust smell to the point i take outside of the garage immediately.  you can smell that even outside in the open.

is there a video or steps to help conduct a signal test? could it be the ignition is not sending correct signal to ECU?

 

[ira]

not sure which oscilloscope to look for..  id appreciate it if one can be recommended on amazon or ebay.

i see digital ones, some say for car audio, others diode testers.  DC/AC

[Dave WM]

disable 6 when cold does it have any effect on idle?

after warm up disable 6 does it have any effect on idle?

swap 6 with 5 repeat test cold and warm

the video did not work for me btw.

Lastly something to consider even when everything is working, the enrichment circuit adds fuel right after startup for a few minutes, this is above the normal CSV and temp sender enrichment.

Its very hard to remote diagnose even if the video worked. You mentioned a strong gas odor, that would make you think its maybe not getting a good spark and perhaps when it leans out some after warm up #6 is just not igniting. the color tune will help with that. put it in 6 observe the color (should be yellow cold) then watch to see if it goes to blue (correct mix) and then dark but for a spark (flame out).

 

the car may run just a tad rougher when idling after fully warm vs when cold just do to the leaner enrichment. I am not talking big differences here, at least on my car that is the way it is. I have thought of adjusting the AFM bypass to see if I can richen up the circuit (presuming that is why its just a tad rougher idle when fully warmed up), but have never bothered to try it as its really minor. The EFI is rather primitive (batch fire, open loop) so its prob setup to pass emissions on the lean side of things.

I don't think the above statement is your issue, just stating my cars operation from cold to fully warm.

 

 

 

 

 

Edited November 24, 2020 by Dave WM

[JSM]

To add more to the mix, I had an 82 Turbo that ran fine cold, but once warmed up it would run really rough at times.  The ECU was exposed right by my foot.  I accidently bumped the plug going into the ECU and it ran great!  When ever the car would do this I would do this and it ran great.  It was repeatable.

Those ECU plugs have known connectivity issues.  I'm pretty sure there are some guys who have upgraded to the Z31 ECU plugs because of it.  And I'm not talking about upgrading to the Z31 ECU, just the plugs.

Edited November 24, 2020 by JSM

[ira]

7 hours ago, Dave WM said:

disable 6 when cold does it have any effect on idle?

after warm up disable 6 does it have any effect on idle?

swap 6 with 5 repeat test cold and warm

the video did not work for me btw.

Lastly something to consider even when everything is working, the enrichment circuit adds fuel right after startup for a few minutes, this is above the normal CSV and temp sender enrichment.

Its very hard to remote diagnose even if the video worked. You mentioned a strong gas odor, that would make you think its maybe not getting a good spark and perhaps when it leans out some after warm up #6 is just not igniting. the color tune will help with that. put it in 6 observe the color (should be yellow cold) then watch to see if it goes to blue (correct mix) and then dark but for a spark (flame out).

 

the car may run just a tad rougher when idling after fully warm vs when cold just do to the leaner enrichment. I am not talking big differences here, at least on my car that is the way it is. I have thought of adjusting the AFM bypass to see if I can richen up the circuit (presuming that is why its just a tad rougher idle when fully warmed up), but have never bothered to try it as its really minor. The EFI is rather primitive (batch fire, open loop) so its prob setup to pass emissions on the lean side of things.

I don't think the above statement is your issue, just stating my cars operation from cold to fully warm.

 

 

 

 

 

i swapped inject6 w inject 5, and the problem followed. as soon as i unplug harness on any injector engine will act up except on the new injector which i snow in position number 5. 

 

So even though it sprays can it be a bad injector?

Whats next?

[ira]

3 hours ago, JSM said:

To add more to the mix, I had an 82 Turbo that ran fine cold, but once warmed up it would run really rough at times.  The ECU was exposed right by my foot.  I accidently bumped the plug going into the ECU and it ran great!  When ever the car would do this I would do this and it ran great.  It was repeatable.

Those ECU plugs have known connectivity issues.  I'm pretty sure there are some guys who have upgraded to the Z31 ECU plugs because of it.  And I'm not talking about upgrading to the Z31 ECU, just the plugs.

Hey JSM, and tnx for sharing.

my ECU was replaced by my trusted mechanic few years ago.  my dad accidently plugged the battery backwards and fried few things. several parts were replaced at that point.  one of which the distributor.

  im pretty confident its a healthy ECU but i don't have a way to prove that.  as for the connectors, they are nicely snug and safely covered.  i dont mind upgrading connectors if u have link for one.

[Zed Head]

1 hour ago, ira said:

i swapped inject6 w inject 5, and the problem followed. as soon as i unplug harness on any injector engine will act up except on the new injector which i snow in position number 5. 

 

So even though it sprays can it be a bad injector?

Whats next?

It does sound like that injector is bad.  I would replace it.  Make sure you get a turbo injector.

We might never know what's going on with your distributor cap.

[ira]

43 minutes ago, Zed Head said:

It does sound like that injector is bad.  I would replace it.  Make sure you get a turbo injector.

We might never know what's going on with your distributor cap.

i had previously put a link for the injector i purchased and it was for sure fit for the turbo model.  can some one recommend a brand?

 

tnx

[Zed Head]

Take it back and exchange it. It's no good.

People like the Standard products.  Here's one.

https://www.oreillyauto.com/detail/b/standard-intermotor-5820/fuel---emissions-16775/fuel-injection-16471/diesel-fuel-injector-17271/fuel-injector-12310/8cc64890b5e0/standard-intermotor-fuel-injector-new/fj23/6010627/1982/nissan/280zx?q=fuel+injector&pos=0

[dutchzcarguy]

9 hours ago, Zed Head said:

Take it back and exchange it. It's no good.

sayd it before.. new does not mean "good" .. the injector is one of the (many?) problems.