Injector question.

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eccs19
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In my process of trying to get the 944 running, I cleaned and serviced / rebuilt the injectors. I replaced the hard plastic caps that go over the needles. They were difficult to get on, but I did get them to pop into place and figured they’d never come off again because of the tight fit. But when I did my intake removal to fix my vacuum leaks, when I pulled the rail out of the intake, all 4 of those caps popped off and stayed in the intake. I assume this isn’t normal? It was a kit for the 944 style injectors. But maybe just a crap kit? Will I be fine to just snap them back in place when I reassemble the intake?

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spacecad3t
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Actually, it is "normal", not ideal, but definitely happens. I use a pick or tweezers to gently pull them out, be careful as the plastic can be brittle. You may want to debur the bores as something is probably grabbing the plastic.

When I rebuilt my injectors, I removed the fuel rail and all 4 caps remained in the bores. They where so dry and broken, my heart skipped a beat because I thought plastic was going to fall into cylinders. I just left the pieces in place, removed the intake, and then picked all the pieces out.

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Tom
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The standard Bosch injector kit has those bright yellow caps that just don't fit right -- not sure why but they've been selling the same kit for decades, with your exact results. If you have your original caps still, just re-use those. If not, a few of the 944 parts suppliers, starting with Rennbay, have found a kit that fits much better.

https://rennbay.com/Fuel-System/944-Fue ... l-Kit.html

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eccs19
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spacecad3t wrote: Fri May 22, 2026 7:05 am Actually, it is "normal", not ideal, but definitely happens. I use a pick or tweezers to gently pull them out, be careful as the plastic can be brittle. You may want to debur the bores as something is probably grabbing the plastic.

When I rebuilt my injectors, I removed the fuel rail and all 4 caps remained in the bores. They where so dry and broken, my heart skipped a beat because I thought plastic was going to fall into cylinders. I just left the pieces in place, removed the intake, and then picked all the pieces out.
Luckily it was easy enough to get the pieces out, but was definately a little shocking that they came off so easily when they were such a pain to install.

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eccs19
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Tom wrote: Fri May 22, 2026 7:27 am The standard Bosch injector kit has those bright yellow caps that just don't fit right -- not sure why but they've been selling the same kit for decades, with your exact results. If you have your original caps still, just re-use those. If not, a few of the 944 parts suppliers, starting with Rennbay, have found a kit that fits much better.

https://rennbay.com/Fuel-System/944-Fue ... l-Kit.html
At least it's good to know it's "normal". I did end up reusing one of the original caps because one broke installing it originally. But even the original one fell off when removing the fuel rail.

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