Injector rebuild

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Sep 13, 2011 | 02:44 PM

eatont9999

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From: Fort Worth, TX

Injector rebuild

OK, I need some opinions here. The scenario is I have one bad injector and no functional new injectors to replace it with. I have a set of old injectors and one new injector that my dumb *** cross-threaded the fuel input. Assuming the new injector's internals are up to spec, I disassembled an old injector and the new one. I swapped the top (bolt shaped) part of an old injector with the lower half and internals of the new injector.

I replaced everything as in the way it came out. I tightened the base of the injector to 55 Ft/lbs. I got that number by setting my torque wrench to 60 ft/lbs and then using it to unscrew the bottom half of the new injector. It unscrewed right before the wrench was going to click.

I don't know what the torque is supposed to be, do any of you know? I wonder if this injector will even work. I don't see why not.

Sep 13, 2011 | 03:29 PM

Lazy K

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https://www.ford-trucks.com/forums/3...que-specs.html Have a read here.

Sep 13, 2011 | 04:43 PM

eatont9999

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From: Fort Worth, TX

Thanks for your reply but that's not quite what I meant. I disassembled a single injector and swapped the internal parts. I reassembled the injector at 55 ft/lbs and I am wondering if that is the correct torque. I am not installing an injector into the head.

Sep 13, 2011 | 04:49 PM

mechmagcn

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From: Moro Bay, AR

Quote:

Originally Posted by eatont9999

While the torque is somewhat critical here, I would be more concerned if the pop pressure was affected by the swapping of parts. If you can find someone locally that can check the pressure, it should be good to go.

Sep 13, 2011 | 04:50 PM

Lazy K

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Oops. Misread. I don`t know but I would think you could not be far away at 55ft.lbs.

Sep 13, 2011 | 05:00 PM

tecgod13

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From: Western Mass

Quote:

Originally Posted by mechmagcn

You're correct. Swapping the parts will change the pop pressure. Each injector might be milled slightly different, and the strength of the spring slightly different. That is what the shims in the injector are for. By changing the shim thickness, you alter the pre-load on the spring and thus the pressure it takes to fire the injector. Small changes can be made by tweaking the torque value.

I'm not sure on the spec for the injector torque, its probably not commonly known as the general public wasn't meant to rebuild injectors. I could look up the value for VW injectors if you wanted, but I don't know if that would be of any use.

Sep 13, 2011 | 05:10 PM

eatont9999

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Cargo Master

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From: Fort Worth, TX

I think I read somewhere that mentioned Mercedes injectors were around 55 ft/lbs. I would take it somewhere to have it pop tested but if it is not perfect, then I run into rebuilding and cleaning fees. It would turn into a $50-$60 injector when I can buy one for $30. I was just screwing around and wondering what people think. I really need to get a pop tester and some rebuilding stuff so I can rebuild injectors and not have to pay other people.