After I tightened the first leaking one, another is now puffing a bit. Maybe I didn't notice it as much as the first one was dramatically throwing fuel all over the place and the return line was jumping up and down like a piston.

I guess in all the excitement of getting this thing and fixing er up, I missed the second injector leak.

I was testing the sending unit change-out and I thought I heard what was like a lifter tap. After inspection, I could feel a little pressure puffing out the third injector back, but it's not throwing any fuel.

Can I drive the truck around easy while I wait till the weekend to fix this?

Thanks.

 

Just a tip, watch your hands around that high pressure from the injection system. Known to cut and get into blood stream. Use a sheet of paper to help detect leaks.
-Good luck: Jake

 

An as an afterthought, when I'm past lower speeds, the tapping/puffing goes away quick and is not there at cruising speed.

I'm wondering at cruising speed operating pressure if there's air entering into the system affecting performance/economy?

A theoretical question to understand operation as I've read up a bit on air infiltration, but I'm guessing it's concerning the suction side of the fuel pump. Right or wrong?

 

You're right, air cannot enter on the pressure side of the engine while it's running, it can only leak fuel. A leak on the high pressure side of the injection pump will deliver less fuel to that cylinder and can cause a knock.

 

It sounds like the injector is lose in the head and leaking compression not the line leaking fuel.

 

DZL is right about injection injuries. It would be just like taking a syringe and injecting diesel into your finger. That's also why they have tip guards on airless sprayers. I saw a guy bump his trigger on accident once and it was only latex paint but it took them 8 hours with a water pick and scalpel to try to save his hand. It causes severe necropsy in the flesh nerves and muscles. Latex paint and diesel also grow fungus very quickly which adds to the problem. Injection injuries are no joke. Be careful of any kind of fluid under high pressures.
P.S. I was running a crew of young painters in San Diego about 12 years ago and they didn't take safety as seriously as I did. I continually told them to always lock the trigger on their spray guns before trying to climb down the ladder because if the ladder moves and you reach out to stabilize yourself you're going to squeeze that trigger you have you finger on. Anyways after Me telling them didn't seem to have an effect I pulled an orange off of a tree and stuck my gun against it and pulled the trigger. I wiped the paint from the outside and showed them the orange. You could barely see the injection site so they started snickering at me. Then I took a knife and cut it open. The entire inside of the orange was brown (brown paint) and the inside of the orange was all blown out only the skin was holding it together. After all of the gasps of horror my guys took the gun a little more seriously.

 

Great. Theory becomes principle. Just a little clearer on diesel operation each day.

As for the finger probing of the injector leak, thankfully, it was only slight. That's why I figured it wouldn't be a problem to take it to work and keep testing the rest of the truck until the weekend.

I remember in the Navy, late 70s, they started to inject vaccines into your shoulder with a gun. I was pretty impressed with the way it worked, though I admit I didn't think of the potential injury while I was fingering the injector.

Thanks for the heads up.

Whoops, showed my age.