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-   280ZX Performance / Technical (https://www.zdriver.com/forums/280zx-performance-technical-79/)
-   -   Idle Hangs in neutral... (https://www.zdriver.com/forums/280zx-performance-technical-79/idle-hangs-neutral-22205/)

naviathan Mar 22, 2007 01:29 PM

Pull the plug off the cold start valve. Better yet pull the injector rail up, turn the key on to kick the pump over and make sure your injectors aren't leaking. If it passes put it back together, leave the cold start valve unplugged and take her for a test run. If she still does, pull the AFM to throttle body boot off, look inside while holding them up to a light source and pull the rubber folds apart to see if there's any leaks. If you see light, get another AFM boot. If that isn't it take a can of carb cleaner, spray around your fuel injectors and the base of the intake. If your idle jumps or settles or makes any changes in a certain spot you have a vacuum leak there. If that doesn't work, check the EGR valve. Pull the vacuum line off it and pull vacuum through. If it holds the vacuum it should be good. Do the same on the brake booster line. Last but not least, kick the ECU a couple times and see if ti settles out. Sometimes it's bad solder joints or components in the ECU that randomly screw up. Try checking the O2 sensor also. There's a light on the ECU that should flash with the O2 readings after it goes into "closed loop" mode. Good luck and check out http://www.atlanticz.ca/zclub/techtips/

thxone Mar 22, 2007 01:32 PM

I will look into all of that except the O2...there is none on the 1979.

naviathan Mar 23, 2007 04:30 AM

There isn't one on the 79? Hmm, odd I could have sworn my Fairlady had one. Oh well. Sorry for the long list of things to look at, but troubleshooting can be a bitch.

thxone Mar 23, 2007 11:05 AM

It's ok, I like a long list....helps when I am bored....Well, I am off to GA. Cya!!!

Bleach Mar 23, 2007 01:43 PM

you should have left your intake manifold with electronics in the car. Just swap the block/head. :(

z-hag Mar 23, 2007 04:44 PM


Originally Posted by snwbrderphat540
that whine could be the fan,.........

very first time i heard my fan in my na WORKING PROPERLY i thought i had a problem----their fans are very loud.......could you be hearing that while you are seeking things to be3 wrong?????

good luck, kiddo--howza come yer never in chat anymore?????

make yer car good and reliable--i knowe--those words seem oxymoronic with zs, but they can be................

thxone Mar 25, 2007 06:44 PM

Hey everyone, I am back from Ga. The car did ok when driving on the interstate between 70-90mph...felt solid. It was all the stop and go crap that made me mad as the car wants to be a prick. I drove around with my buddy in his 1980 2+2 5 speed....man, I know now how my car is "supposed" to feel and pull...I did help him with his idle and he had never noticed but his vacuum line to his dizzy was off...so we fixed that and he was very happy...that car is a beast. I am so jealous. I do think that alot of my problems are vacuum related....I think it is time to replace ALL the vacuum lines...if that don't work...I AM BURNING THE CAR!!!!

snwbrderphat540 Mar 25, 2007 07:08 PM

do it, i did it with all blue silicone lines, only takes like 10 min. there arent that many lol

thxone Mar 29, 2007 11:56 AM

Ok, I bypassed that thing under the TB and re-routed some vacuum lines...the car is still actin funny but I don't think it is hanging as high now on the tach. The car is running rich as hell and has been since I got it...there is a connection on the intake that has a fuel line running to it, I took it out and cleaned it, I think it actually sprays fuel into the intake for some reason...maybe it is spraying all the time??? All I know is the car wants to act funny when I floor it and the exhaust smells of raw fuel even when idling with grayish smoke...but very little smoke. Do I even need this damn part hooked up??? What is it for?

Also, I think I may need a clutch...maybe. Unless my problems are just electrical but if I pop the clutch in first somewhere between 4,000 and 5,000rpm it does not roast my tires :paranoid: and I know it should be doing that dammit...but I did that once and when it didn't roast my marshmallows I decided to just drive like a normal person till I fix the car. Help me, somebody help me!! Mashed Potatoes, Gravy and Cranbury Sauce...WoooooohoooooOOoo....eh! :022:

NismoPick Mar 29, 2007 12:08 PM


Originally Posted by thxone
there is a connection on the intake that has a fuel line running to it, I took it out and cleaned it, I think it actually sprays fuel into the intake for some reason...maybe it is spraying all the time??? All I know is the car wants to act funny when I floor it and the exhaust smells of raw fuel even when idling with grayish smoke...but very little smoke. Do I even need this damn part hooked up??? What is it for?

I assume you are talking about the cold start valve... sits just behind the throttle body & has a fuel line running back to the fuel rail right? Anyway... the name says it all. You can pull it while the car is running & see if it's spraying... or just pull the connection.

As for your clutch... dropping it at 4 - 5k rpm will deffinately lower a stock clutch's life. :D Usually if the clutch is going out, you will feel it on the freeway.... 70mph+ you will feel the engine start to rev, but not increase in speed. AKA... "slippage"

thxone Mar 29, 2007 12:10 PM


Originally Posted by NismoPick
I assume you are talking about the cold start valve... sits just behind the throttle body & has a fuel line running back to the fuel rail right? Anyway... the name says it all. You can pull it while the car is running & see if it's spraying... or just pull the connection.

As for your clutch... dropping it at 4 - 5k rpm will deffinately lower a stock clutch's life. :D Usually if the clutch is going out, you will feel it on the freeway.... 70mph+ you will feel the engine start to rev, but not increase in speed. AKA... "slippage"

Ok, the clutch must be fine cause even at 90mph for 30min it was cool.

Ok, so if this "cold start valve" is messed up can it cause a rich fuel mixture and or make the car rev high AFTER it has warmed up??

NismoPick Mar 29, 2007 12:18 PM


Originally Posted by thxone
Ok, so if this "cold start valve" is messed up can it cause a rich fuel mixture and or make the car rev high AFTER it has warmed up??

Tis a possibility I guess... They usually get stuck closed, not open, but it could happen.

naviathan Mar 29, 2007 02:17 PM

Oh I've heard of them getting stuck open and they cause a really rich condition. How do you know it's running rich? If the idle is staying up and it's caused by a vacuum leak it would run lean, not rich.

thxone Mar 29, 2007 04:50 PM

I have no idea WHATS wrong with the car all I know is it is running like poo poo and I want it to run correctly. I am so sad.

BigBirdsZ Mar 29, 2007 05:29 PM

i got a 79 u can borrow my throttle body to see if thats it, but only borros cuz i needs throttle

thxone Mar 29, 2007 05:47 PM


Originally Posted by BigBirdsZ
i got a 79 u can borrow my throttle body to see if thats it, but only borros cuz i needs throttle

I will get with you soon, I am not sure how full my weekend is yet....and my car is being a prick.


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