un sticking fuel injectors

[Dave WM]

I am still working on them 4 are clicking loudly, 1 a soft click  the other still stone quiet. I have them soaking in the nasty stuff they sell in 1 gallon paint cans with a basket, they have been in there for a couple days at about 1.5 amps which is way more than needed, but at this point its just an experiment.

[Captain Obvious]

At fifty cents apiece, it seems like it would be a worthwhile experiment to remove the original plastic pintle cap in order to be able to push on the tip of the valve and see if you can move it, or if it's stuck in place.

Since this is a science experiment, right?

[Dave WM]

I am thinking of making a small tool, it seems the pin you see is attached to a larger dia inner piston, If I get some brass (easy to machine) I could drill a center hole to fit over the pin, then turn a "hammer" end that fits the OD of the plunger a tiny bit smaller than the fix part of the injector. that would allow me to really bang on it. I direct strike on the pin would just bend it.

[Captain Obvious]

Oh. That's fancy.

I wasn't thinking hitting it with a hammer... I was picturing just pushing on the end with the plastic handle of a screwdriver. And if that didn't produce any interesting results, a requisite knock with the same said plastic handle.

I figure if it takes much more than that, you'll never get it moving freely enough that the electromagnet would work.

[Zed Head]

Some of the caps are made of rubbery material.  You can twist them off, but still reuse them.

I have some old injectors I can go poke at.  Pretty sure the spring is not that strong.

 

[Zed Head]

I just went out and pressed on the pintle tip of a functionable injector using a small allen wrench.  I could feel it opening and closing, tick-tick-tick.  Really didn't take much force at all.  I didn't feel like it was even close to being damaged.  It felt about like what it is, a small spring loaded valve.

If you can't get it open using just slight hand force, it's probably toast.

Edited February 21, 2019 by Zed Head

[Captain Obvious]

3 minutes ago, Zed Head said:

If you can't get it open using just slight hand force, it's probably toast.

That's what I figured. That spring can't be too strong as it has to be overcome by that small electromagnet.

If the valve is frozen shut due to crusted fuel, you just might be able to manually open it to get some cleaner through it. But if it's a packed solid rusty mess inside, even being able to move that pintle tip probably won't save it.

[Zed Head]

I can shoot some old injectors out to you if you want to make a matched set.  I have some BWD auto store brand, some Bosch, and a full set of rusty looking but balanced 1978 Denso (I think, whatever the OEM brand was).

[Dave WM]

Thanks ZH,  JSM and Av8ferg have already offered up some if I fail a this attempt. I just went out to garage, one of the injectors (a working one no less) had one of its copper teeth completely eaten up by I presume the long exposure to the cleaning solution, did not figure on that. But one of the other started working, so I have 5 that are clacking, no ideal if they will flow. I will see if can get one more from JSM as he is local to me and then setup a flow station (the fuel pump and stock rail) to see if they flow. I will keep you in mind if the other that have been offered turn out to have issues.