Extremely high idle

[Hrududu]

Okay, so i took my 77 280Z into the shop to get the ball joints replaced as well as my front struts. While it was there, a fuel hose connecting to my fuel filter apparently had a bit of a leak, so they tightened down the clap. I got the car back today and now it will not idle any slower than 2300rpm. I tried adjusting the idle screw as well as looked around for anything obvious. Aside from tightening that clamp, they didn't do anything else under the hood. Before I took it in I had no problems like this. I was idling at 800rpms nothing was wrong. I took it back and had them look at it and they cannot figure out whats wrong. Anyone here have any suggestions as to what I can look for or do? I'd appreciate any help. Thanks.

[28Zero]

While I don't know how it would have happened in your case, but one thing that caused a very high idle in my 78 280z was a stuck booster control valve. Once the car warmed up, there was no getting it back down.

Hope that helps.

Cheers,

James

[zeiss150]

ummmm im just guessing so I could be totally wrong but here go's ... check the throttle body and make sure its not hung up on anything, check your AFM make sure that the flap doesn't have anything stuck keeping it open, check any leakes in the rubber leading to the AFM, look for any vacuum leaks, check the throttle linkage from the peddle to the TB see if its stuck anywhere, this one is a long shot but make sure the timming wasn't messed with. thats all I can think of

Good luck!

[Maddos]

Try disconnecting throttle linkage across firewall or at carbs to see if is being held open a little.

[deadflo]

Fuel injected Z's can have high idle issues when large rubber boots connecteing the air flow meter to the intake get cracks, because unmetered air is entering the system. I would look for small cracks in the boot.

[jjacquot]

I recently put SU carbs on my 73 and I have the same problem. From what I can tell on mine it is the throttle linkage. I can move the linkage so it idles normal (about 800 rpm) and it will stay there but when I rev it up it will only idle down to about 2300 rpm. I came apon this problem last night and I can't figure out how to make it go back to normal either. Is anybody familiar with this problem?

[Hrududu]

Hey guys, i fixed the problem. As it turns out, a nut had fallen on the throttle linkage down near the throttlebody and was not allowing it to go all the way down. No idea how it got there, but i noticed it looked like it wasn't going down all the way and there it was. Took a screwdriver and knocked it off. Now there arn't any problems. I took the pics below to show you where it was. These are on my spare motor so it is easier to see.

[sblake01]

That would do it. Is that a strut nut? If so, I'd give 'em hell at the shop

[EScanlon]

My question involves why there would be a loose nut floating about the engine compartment when all they did was tighten down a fuel line clamp and ball joints.

Would replacing the ball joints involve removing the strut?

And if that is the case, when they went to put it back and they discovered that they were shy one nut they just....what? Blew it off? Found another and disregarded where the original disappeared to? And, most importantly, after having done work on the car's steering they did not take it out for a test drive or even start it up to move it out of the bay? Hmmm, I would definitely have some quetions about their procedures.

Not to lambaste your mechanic, but something is fishy in the state of Kansas....and it's not a coastal state.

2¢

E

[240ZX]

From the size of the nut it looks as though, like Blake said, it may be one of your strut fastening nuts! It seems very odd and highly unlikely that a nut that size found its way onto the throttle stop.....and it could have only gotten there with the throttle open! I smell fish too!!!

[sblake01]

My question involves why there would be a loose nut floating about the engine compartment when all they did was tighten down a fuel line clamp and ball joints.

Would replacing the ball joints involve removing the strut?

E

He said in his post that he took his car the the shop to have the ball joints replaced as well as the front struts. Which still leads to the faint odor of pescado!

[EScanlon]

Good catch Stephen, I missed that part.

But I agree with you, where were they putting the nuts they were removing that they didn't notice one missing....and further, why did they just go get another without questioning the missing part.

Then to top it off, No test drive? Or did that problem arise AFTER it had been picked up and driven a bit.

E