Severe white smoke on start up. 8v71N N70 injectors

[MikeMck]

Suspect a bad injector or 2. Based on research and knowledgeable suggestions IR gun is on the way.
Trying to determine which is the bad injector.
Interested in thoughts and ideas.

[Sonic Boom]

just look for the cold cylinder and you'll find it. Remember seeing he old timers feel the exhaust port with their bare hand but IR gun works too.

[rsmith]

Pull the valve covers and drop each cylinder out by holding down the injector with a screwdriver. The rpm drop will be less on the bad cylinder

[Captain Ralph]

White smoke is un-burned fuel ignited in the exhaust manifold by the hot exhaust from other cylinders.
Starting a cold engine may make a lil white smoke but lots of smoke is usually not good.

I recall you stated that is does clear and runs clean. How soon does it clear?

If it clears in a few moments before anythings gets warm, it's leaking injectors.

I had an exchange set like this, that ran great but leaked down when sitting and fuel just puddled up on the piston tops till cranked up and the lungs cleared them selves. Big white cloud that cleared in a minute but still ticked everybody off. You will have to work quick with a IR gun but I recommend the whole set going to a good injector shop to fix the leak downs and match them all up together.
This was another event that taught me to never buy injectors off he shelf, Always fix, pop and match what you have.

Now, if the engine needs to start getting warm before it clears of smoke, we have a low compression issue in one or more cylinders. Working quick again, hold down the tappet on each injector with a big screwdriver as rsmith suggest or lil goose neck bar as I mentioned yesterday. You may find the bad lung this way till it clears or warms up.

A cold valve adjustment may help also. If you find any tight valves you found your bad lung (bad valve or valve seat).
Short of a compression check, pull the side covers off the cylinders and inspect the liners, piston and rings. a broken ring or scored liner can cause this also.

How about smoke under load? White or dark?

[MikeMck]

White smoke is un-burned fuel ignited in the exhaust manifold by the hot exhaust from other cylinders.
Starting a cold engine may make a lil white smoke but lots of smoke is usually not good.

I recall you stated that is does clear and runs clean. How soon does it clear?

If it clears in a few moments before anythings gets warm, it's leaking injectors.

I had an exchange set like this, that ran great but leaked down when sitting and fuel just puddled up on the piston tops till cranked up and the lungs cleared them selves. Big white cloud that cleared in a minute but still ticked everybody off. You will have to work quick with a IR gun but I recommend the whole set going to a good injector shop to fix the leak downs and match them all up together.
This was another event that taught me to never buy injectors off he shelf, Always fix, pop and match what you have.

Now, if the engine needs to start getting warm before it clears of smoke, we have a low compression issue in one or more cylinders. Working quick again, hold down the tappet on each injector with a big screwdriver as rsmith suggest or lil goose neck bar as I mentioned yesterday. You may find the bad lung this way till it clears or warms up.

A cold valve adjustment may help also. If you find any tight valves you found your bad lung (bad valve or valve seat).
Short of a compression check, pull the side covers off the cylinders and inspect the liners, piston and rings. a broken ring or scored liner can cause this also.

How about smoke under load? White or dark?


Sounding like original plan of pulling all the injectors and and having them tested is the next step.

As to smoke under load. No smoke once at operating temp.
Headed back to the boat next week as the Marina has been locked down to non Marina personnel but now allowing local workman in again.

[JaxCap]

Any update?

[MikeMck]

Any update?

I will be back in Ensenada in a couple days. Marina letting mechanics back in to work on boats with owner authorization.
Expect update in a week or 2.
Mike