Engine idleing at 1500 and running rich...

[sonofzzzap]

I have a 1977 280z, and I have been troubleshooting this area since I got her home on the 27th. It seems to be in great running condition, no smoke or any other problems that I have found. She runs a little rich(you can smell the fumes) and the engine idles at 1500rpm (which is too high). I would just like to get some feedback on the subject, maybe some possible solutions? I appreciate it guys. *Note* I can idle her down, I don't know if it would change the richness

[Gav240z]

idle her down it should not change it's richness.

Fumes are a common complaint and there are many topics in our archives that discuss where they come from and how to prevent them. Do a search and you should find your answers.

if you still have questions just ask!

[sonofzzzap]

thankyou very much! I'm a first time Z owner and there are many things I need to learn, I appreciate your help

[webdawg1]

You might want to download and print out the "EFI Bible" for starters at the following link.

http://www.72hours.net/~zcar/

Also get a FSM (Factory Service Manual) for your model year (1977) as the "EFI Bible" makes reference to various pages and troubleshooting steps in the FSM. You can find them on eBay pretty much all the time. I can also send you a wiring diagram (PDF format) for your model year (1977) if you will PM me with your email address.

webdawg1

[AChev]

Like you, I was very recently all new to this Z stuff. You will find here that everybody is looking to help, any questions you have people jump to help you. About the idle, like Gav said adjust the idle to lower should not adjust the richness as there are two seperate adjusments for the fuel/air mixutre and the idle speed

[sonofzzzap]

I appreciate all the help guys, im slowly learning. I wanting to get into them and work on them alot more. I love my 280, and I dont think I will ever get rid of her.

[sblake01]

Have you looked into the thermotime switch/cold start valve combo? A leaking CSV or a faulty TTS could cause this slight richness you speak of.

[sonofzzzap]

Hmmm, do you have more info on that one blake?

[sblake01]

The thermotime switch senses coolant temperature. It gets a signal from the starter while cranking. If the temperature is cold enough, I believe below 35 celsius, it sends a signal to the cold start valve which is basically an extra fuel injector used for cold starting only. If the thermotime switch sticks closed, it will continue to send that signal even when warm which will make the fuel mixture rich. Also if the cold start valve leaks it will also cause richness. You really should get a FSM or read through the 'EFI Bible' as it covers the procedure for checking the function of these two items. These are not to only things that can cause richness but it's where I'd start.