carb issue?

[thestrange]

Now that i have my truck running reliably, i am having another small issue. i can drive all day long with no problems, but when i shut off my truck it will chug for 5-10sec with the key off. it also has a high idle after it's warmed up. the idle is probably from a vacuum leak, that i know. but what would make it keep running after its shut off?

[Dat Lurka]

Anti Dieseling Solenoid can be the culprit.

The wire can go bad like mind did OR it's not plugged in.

But then again I have no idea what engine or carb you have.

It will also cause the high idle.

It is a solenoid at the carb. I'll find a pic.

[Dat Lurka]

[ggzilla]

If that is not plugged in, the engine won't idle.

 

One thing tha can cause dieseling (run-on) is if the valve is stuck open, or someone has removed the needle valve from inside the valve.

[datsunaholic]

They rarely get stuck open. What happens is they get stuck CLOSED (or are disconnected) and someone then resolves the resulting no-idle condition by cranking the idle speed screw in, making it idle on the mains. Then it will sure as hell diesel. Especially if they cranked the idle speed screw in so much they made it idle fast (since it doesn't idle very well on the mains to begin with).

[Smyrna720]

They rarely get stuck open. What happens is they get stuck CLOSED (or are disconnected) and someone then resolves the resulting no-idle condition by cranking the idle speed screw in, making it idle on the mains. Then it will sure as hell diesel. Especially if they cranked the idle speed screw in so much they made it idle fast (since it doesn't idle very well on the mains to begin with).

 

Quoted for truth. Seen it just this last weekend on an 86 B11 Sentra.

[thestrange]

It's the z22 with a weber carb, not sure which model. When i first start it, it idles at 800-900 rpms. its only after i drive it for a while and its warmed up, that the idles at 1700-2k rpms. Only then will it try to run after the keys off.

[datsunaholic]

Depends on if the weber has an idle cutoff solenoid or not. Some do, most don't. But high idle like that indicates the choke isn't set right, and is remaining partially closed, leaving it in high idle. And that will cause run on, though Webers are notorious for run-on anyway (particularly the one without the idle cut solenoid).

[thestrange]

I'll have to poke around the carb tomorrow.

thanks for all the feed back.

[thestrange]

It appears to be the 32/36 DGEV. It will also sputter when the secondary opens (most likely clogged jet?) I fiddled with the choke a little by cleaning the wire contact, and making sure the spring inside was clean. Then I put it exactly back the way it was. Should I try adjusting the choke housing, to see if that's the issue? I also plan on gutting and cleaning the carb when I get some cash, can I just get a weber gasket kit from autozone or Napa?