Volvo MD22 Fuel Injector Leak

[Harryfl Arnold]

Four fuel injectors rebuilt. Put them back in and #1,#2, and #4 bubble (leak) when doused with fuel after engine started. #3 popped and ejected vaporized fuel (or exhaust) with each stroke. Two mechanics (cruisers) are dumbfounded: Is it the wrong copper seal washers supplied by the rebuild company? Is it the 4-spring injector hold-downs that lost their spring? Help, please!! Harry

[sailcapt]

Originally Posted by Harryfl Arnold

Four fuel injectors rebuilt. Put them back in and #1,#2, and #4 bubble (leak) when doused with fuel after engine started. #3 popped and ejected vaporized fuel (or exhaust) with each stroke. Two mechanics (cruisers) are dumbfounded: Is it the wrong copper seal washers supplied by the rebuild company? Is it the 4-spring injector hold-downs that lost their spring? Help, please!! Harry

Harry,
It looks like you might have to reface the injector seat. Sometimes it will get distorted with carbon deposits. Will chat with you later today.
Steve

[Chief Engineer]

Sounds like seats are carboned up or washers are wrong or too hard and need annealing

[Harryfl Arnold]

You're the second one to say this. I'll take the injector out, polish the seat, heat the washers to "RED HOT" and drop them in cold water, reassemble and see. Thanks for the reply! I'll post the outcome.

[GordMay]

Here’s an interesting & informative article on Fuel Injection Inspection
➥ http://www.sailmag.com/boatworks/BW4.Injectors.pdf

[Chief Engineer]

Originally Posted by Harryfl Arnold

You're the second one to say this. I'll take the injector out, polish the seat, heat the washers to "RED HOT" and drop them in cold water, reassemble and see. Thanks for the reply! I'll post the outcome.

NONONONONONONONO

HEATING AND QUENCHING WILL HARDEN THE WASHER

HEAT AND ALLOW TO COOL IN AIR

[GordMay]

Annealing is used to induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties.
This process is performed by substantially heating the material, generally until glowing, then allowing it to cool (usually, slowly in air).
Steel will be hardened if quickly quenched in water, and must be cooled slowly (in air or furnace) to anneal.
However, copper and brass can be either cooled slowly, or quickly by quenching in water.
You do not need to anneal new washers. They come out of the manufacturing process soft and ductile. You only need to re-anneal used washers that have been worked.

[Harryfl Arnold]

Yes, carbon and washers (.089" v. .087" thick) seem to be the problem. I used an old injector with the washer still attached with jeweler's polish and polished the seat. Cut the leakage by 80%. Unfortunately the injector/polish method is too crude to do the job completely. Gotta find a tool to do it right.

THANK YOU, EVERYONE, FOR ALL THE GREAT AND ACCURATE ADVICE.
Harry