sewebster Posted November 11, 2010 Share Posted November 11, 2010 The VG30E fuel rail (with the injectors) is held onto the intake manifold by bolts that have these black plastic pieces. They are essentially 5 mm thick M8 washers. On my truck they are a pain, because they are half broken, and the dealer couldn't replace them. However, on my truck they serve no real purpose that I can tell because the fuel rail is still electrically connected to the intake. Are there supposed to be two insulating washers, one above and below the metal fuel rail tab you bolt through? Does that even really work, because the bolt threads could touch the metal in between the washers... Is there a reason for insulating the fuel injectors etc from the engine? It seems to run fine... but I have the plenum off so this would be a good time to do something about it... http://nissan4u.com/parts/pathfinder/us_wd21/1990_11/type_18/fuel_and_engine_control/fuel_strainer_and_fuel_hose/ That page shows two insulators above and below on one of the bolts I guess, so maybe I'm just missing parts... Link to comment Share on other sites More sharing options...
MY1PATH Posted November 11, 2010 Share Posted November 11, 2010 (edited) If they were originally hat washers they would completely Isolate it but I don't see why you would need that. u sure its not just hard dried out rubber meant to absorb vibration or squish a little if the rail need to seat more? P.S. your link don't work. rubber washers and nylon washers can be found at the harware store. Edited November 11, 2010 by MY1PATH Link to comment Share on other sites More sharing options...
sewebster Posted November 11, 2010 Author Share Posted November 11, 2010 What I have now is quite hard and brittle plastic. It is shiny and really doesn't seem like dried out rubber. They aren't hat washers. I'm guessing they are original since they are somewhat obscure and seem quite old. I also wondered if maybe it was supposed to be some vibration isolation thing. I may have them installed on the wrong side of the fuel rail tab... the diagram in the FSM seems to show them going underneath, but then the injectors don't seat as well. Getting the injectors to seat properly was a major pain. Maybe my fuel rail is somewhat bent or something. The only reason I think of electrical isolation is because this has something to do with fuel, which can ignite, and "electricity" can cause a spark... but I don't see how this would be a problem specifically in this case. Link to comment Share on other sites More sharing options...
sewebster Posted November 11, 2010 Author Share Posted November 11, 2010 (edited) Link works for me... did you click it or copy and paste... need to click. Yeah, getting a nylon washer big enough for M8 seems tricky here, but I did make up some from a teflon tube I had. Nevertheless, without a hat washer system, it isn't really going to work "properly." Rubber washers don't allow the proper torque (12 ft lbs) since they just squash. That might be ok, but I worry about them drying out over time since they'll be hot and then things being loose and having an air leak at the injectors. Unlinked link... http://nissan4u.com/parts/pathfinder/us_wd21/1990_11/type_18/fuel_and_engine_control/fuel_strainer_and_fuel_hose/ Edited November 11, 2010 by sewebster Link to comment Share on other sites More sharing options...
Kingman Posted November 11, 2010 Share Posted November 11, 2010 (edited) I think it's just a rubber spacer they put in there do dampen vibrations so the metal lines don't fatigue. It's the one that goes in between the mounting bracket on the fuel rail and the lower intake manifold, with the manifold allen bolt going through it, right? Think of it this way though: when it comes to something like that, why would a manufacturer add a part that costs more money if it wasn't necessary? They gotta keep their costs down, they aren't going to add something that isn't necessary. Edited November 11, 2010 by Kingman Link to comment Share on other sites More sharing options...
sewebster Posted November 11, 2010 Author Share Posted November 11, 2010 Yeah, I'm sure they had a reason for it (though, engineers can make dumb decisions sometimes...). It's just messed up for me right now, so I'm trying to figure out how to fix it. I can do something that will be mechanically sound, maybe even with some vibration isolation pretty easily. I'm really trying to figure out if I need electrical insulation for some reason. Then I'd machine some special washers or something. But I don't want to do that if I'm not supposed to... "ungrounding" things could be bad for instance. Link to comment Share on other sites More sharing options...
hlenhart Posted February 1, 2019 Share Posted February 1, 2019 Jeeez.... the Insulators are for HEAT, since the whole rail is full of GAS Link to comment Share on other sites More sharing options...
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