280z 280z 78 Wont idle, Running Rich, out of ideas.

[Cyrillink]

8 minutes ago, Reptoid Overlords said:

Not to throw you off the troubleshooting track that's been laid out, but is there a chance that the guy who worked on it before you removed the injector connectors and cross connected them, or in other words, put the wrong connector(s) on the injectors?

Sent from my Coolpad 3310A using Tapatalk
 

Interesting Idea, let me double check the correct wire pattern

[Cyrillink]

14 minutes ago, Cyrillink said:

Interesting Idea, let me double check the correct wire pattern

Checked the injector harness looks to be plugged in correct

[Zed Head]

The injectors all open at the same time.  You can switch plugs at will.  

The throttle valve switch is a possibility.  Stuck at wide open.

Another piece in the meal.

[Zed Head]

[Dave WM]

1 hour ago, Cyrillink said:

Yes, plugs had moisture on them.

What I meant was are the carbon fouled? Also how is the ign timing set?

[Cyrillink]

11 minutes ago, Dave WM said:

What I meant was are the carbon fouled? Also how is the ign timing set?

I tossed in a new set of plugs first thing i did. and timing was set by some one else. i am about to get a timing gun and double check it my self.

[Cyrillink]

34 minutes ago, Zed Head said:

 

Just checked, Looks good to me

[Dodd23]

I had that issue. And I pulled the water temp sensor plug off. Jumped it with a paper clip to close the loop and it ran like a dream. $18 later for a new sensor and all good...... at that time. It thought it was cold and was dumping extra gas from the cold start injector. 

[Cyrillink]

4 minutes ago, Dodd23 said:

I had that issue. And I pulled the water temp sensor plug off. Jumped it with a paper clip to close the loop and it ran like a dream. $18 later for a new sensor and all good...... at that time. It thought it was cold and was dumping extra gas from the cold start injector. 

Thanks for the recommendation going to try the paperclip.

Already have the new sensor installed as well. 

[Zed Head]

3 minutes ago, Cyrillink said:

 

Just checked, Looks good to me

Just like the coolant sensor.  You have to get the numbers at the ECU plug.  The ECU determines how long the injectors stay open.  They do that based on what's coming in through the connection to the harness.

You're on the very well-worn path of people new to the Datsun EFI.  Trying one thing at a time.  By the end you'll have measured all of the things you need to measure, just in two weeks time instead of two hours.  No offense, it is very common.

Your symptoms are also what happens when the ECU goes bad, or the connector gets loose.  People have fixed it, temporarily, by banging on the side of the ECU.  If you had all of the test results and they were in spec. then replacing the ECU would be the last resort.

[Dave WM]

25 minutes ago, Cyrillink said:

I tossed in a new set of plugs first thing i did. and timing was set by some one else. i am about to get a timing gun and double check it my self.

The reason I asked if they are carbon fouled was the early post about running rich. Wet does not mean rich, could be just not igniting. I just wanted you to confirm the initial diagnosis that its running rich. Smelling fuel could be a fuel leak somewhere. I like to start with a new set of plugs, then run it for a few minutes, under varying loads if its drivable, maybe put 10 miles on them, and then pull and examine. A properly setup EFI on a 280z should result in nearly white insulators given that test. I just don't want to be chasing a false premise.  Poor running could be a massive vacuum leak that may not show up as leaking smoke under the hood, say if its a stuck EGR as an example.

 

Edited December 16, 2019 by Dave WM

[Dave WM]

also, did you ever try removing the oil cap while it was running? normally it should stumble and perhaps die while idling. This will help find if the mixture is set incorrectly as well since unmetered air into the system in a correct working system tends to lean out and die. Again this assume all the EFI is in place and properly hooked up.