280z throwing smoke

[mota z]

hello names chris, i have a 76 280z I recently did a trany swap from auto to manual about a month ago. Now my problem is my car is smoking its white grayish smoke.The car has been sitting for about 6 months slowly working on it I finally got the trany in I started my car and the rpms were high at the cold start i tried to lower it but nothing worked . but after it warms up the idle goes down to 9rpm. I have check my plugs no oil on them, my coolant has no signs of oil either. but i did notice oil under my throttle body? can that be whats causing my car to smoke? I have also read that when a automatic trany gives out some fluid can be suck into the manifold so maybe that would also be whats causing the white smoke?

[FastWoman]

Hi Chris,

A high idle speed at startup is normal. There's an air regulator whose job it is to step up the idle until the engine is warm enough to run at a lower RPM. I think 900 RPM might be a bit high for a warm idle, but I don't know the normal idle speed for an automatic. Maybe 750? You can adjust the idle speed with the big screw ontop of the throttle body.

I have to plead ignorance about automatic transmissions, but perhaps a bad modulator could introduce transmission fluid into the intake, as you suggest. I think there should be a vacuum line that leads from the intake manifold to the transmission. Just check it to see if there is any ATF inside it.

If you have oil beneath your throttle body, perhaps something is leaking oil onto the exhaust manifold. Is the smoke coming out the exhaust, or is it coming from under the hood?

Also if you have put your greasy hands all over your exhaust manifold and exhaust in the process of replacing your transmission, then that would generate quite a lot of smoke when the engine is first started. This is fairly unavoidable and normal. Your engine should stop smoking after several minutes and not smoke anymore after that.

[Willoughby Z]

hello names chris, i have a 76 280z I recently did a trany swap from auto to manual about a month ago. Now my problem is my car is smoking its white grayish smoke.The car has been sitting for about 6 months slowly working on it I finally got the trany in I started my car and the rpms were high at the cold start i tried to lower it but nothing worked . but after it warms up the idle goes down to 9rpm. I have check my plugs no oil on them, my coolant has no signs of oil either. but i did notice oil under my throttle body? can that be whats causing my car to smoke? I have also read that when a automatic trany gives out some fluid can be suck into the manifold so maybe that would also be whats causing the white smoke?

I'm confused...' from auto to manual...' is what you wrote, which says you removed an A/T and have an M/T but you refer to something you read regarding problem conditions with auto transmissions

You replaced a manual with an automatic?

[FastWoman]

Ah, I'm a touch dyslexic. Yes, if you have the manual now, there's no possible route for introduction of transmission oil into the intake manifold.

[mota z]

I had a auto tranny that completely gave out n that's when the car started smoking and now i did the swap n have a 5speed in my z. Now i am thinking at the time i still had the auto transmission in there if some liquid got suck in and that's whats causing my car to smoke.:stupid: