Phyxius Posted August 11, 2005 Share Posted August 11, 2005 This fuel rail/injector job turned out to be more trouble than I thought... I've managed to tear some of the o-rings on my injectors trying to get them into the fuel rail. Is there a trick to getting them in without tearing? I tried lubing the o-rings with vegetable oil, but it didn't really work. Also, I'm using the 460cc rx-7 injectors without the pintle caps. The stock injector seals don't really fit right, and the old rx-7 ones won't either without the pintle caps. With the stock 280 seals, there is room to move the injector up and down between the fuel rail and manifold. If I stack the rx-7 seals on top of the stock seals, the room goes away, and it fits tight. Will this work, or will I be leaking fuel under boost? thanks in advance... i know you guys get tired of my silly questions... Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted August 11, 2005 Share Posted August 11, 2005 I ran 550cc rx-7 injectors in the Pallnet rail. The larger 'green' o-rings which came w/ the injectors were too tight, so I went to a smaller o-ring (acquired from a local diesel injection shop) and they slid right in... no leaks... regarding the fitment, I remember I had to take the efi manifold off of the car and drill out the injector holes where the pintle caps go as they were larger than the stockers, and used the stock lower o-rings, and had no fitment issues... The injectors did not move up and down once the fuel rail was tightened down. In fact, I sold that rail, injector and manifold combo to a buddy and did the mods all over for myself using another rail, 550 injectors and manifold. Again, no fitment issues. Mike. Quote Link to comment Share on other sites More sharing options...
clint78z Posted August 11, 2005 Share Posted August 11, 2005 I have the same rail just recieved with 460cc RX7, hope it goes fairly smoothly. Did you get new seals for the top of the injectors, seals get hard when they get old. One other question did you guy reuse the old plastic and metal holdowns from the z where it mates to the manifold?? I was told to leave pintle caps on and use the 280z seals. I will probably use a micrometer when installing everything just to be safe. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 11, 2005 Author Share Posted August 11, 2005 okay, I got some #6 o-rings from the local hardware store, and they went in much more nicely. Everything seems to seal up fine, but I've run into another problem. The fuel pressure gauge spins all the way around past 60psi, and the rail makes a hissing noise. I did tinker with the screw in the bottom of it some, but I tried to put it back where it was when I got it. You guys think i messed up the gauge, or is the (stock)fpr malfunctioning? Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 11, 2005 Author Share Posted August 11, 2005 I have the same rail just recieved with 460cc RX7' date=' hope it goes fairly smoothly. Did you get new seals for the top of the injectors, seals get hard when they get old. One other question did you guy reuse the old plastic and metal holdowns from the z where it mates to the manifold?? I was told to leave pintle caps on and use the 280z seals. I will probably use a micrometer when installing everything just to be safe.[/quote'] I couldnt get the hold downs to fit with the rail. Also, if you leave the pintle caps on, you will have to drill out the holes in the manifold, and the stock seals (at least mine) will not fit anymore. Quote Link to comment Share on other sites More sharing options...
pallnet Posted August 11, 2005 Share Posted August 11, 2005 OK let’s see if we can tackle your issues one at a time. 1) BRACKET FITMENT. The brackets fit just fine and there should not be a space if installed properly. The injectors should be able to twist. One thing to remember is that the brackets and rail is made to fit many 11mm O-ring injectors. If you feel that the brackets could hold your injectors down tighter, just remove the brackets from the rail and lock one at a time in a vice to flatten them out a little. This will increase the clamping force. 2) TEARING O-RINGS. A twisting motion is used to install all injectors into the rail before installing into the intake. The O-rings must be lubed with a silicone lube to reduce the chance of "O-ring swell". This is the best way to install my and other rails on other cars I have worked on for the past 11 years. You are 100% guaranteed to rip O-rings if you put all injectors into the intake and "jam" the rail down on them. You could also damage the bores and or your injectors. 3) LARGE PINTLE INJECTORS. This can be handled 2 ways. I recommend the first although it's more work. Remove the intake and bore the holes of the intake to 17/64" if I remember correctly. Clean the edges and then reinstall the intake. All will go together with the stock Z injector tip seals (Silicone lube again). A customer told me a second way and I do not recommend this. He said to remove the pintle caps all together and just install the injectors without boring the holes. He claims to have no VAC leaks. 4) OVER 60PSI AND HISSING. That right there sounds like a bad FPR or possibly the FPR is hooked up wrong. If you over pressure any fuel rail, you will hear noises like that. I do a lot of pressure testing and I have heard exactly what you’re talking about. For the other guy who asked, do not use the stock injector holders. I have sold many of this style rails. I have walked a few (Not so mechanically inclined) people though installs. I have also heard and seen many improper ways to install my rails. I am using the exact same injectors you speak of and the same rail on my own car. I used stock 11mm O-rings bought from a local parts house with "0" fitment issues and "0" leaking from the injectors or the rail. The rail on my car is the second one I prototyped long before I sold any to you guys. It has been leak tested to over 120psi. I do leak test others (One every5-6 sold) as I make them for quality control. Also I do test fit here before I ship them out. This is why most rails are shipped partially assembled and the brackets may look like they have been bolted down. If none of this helps you out. Email me with your phone # and I will call you and see if I can walk you through the install. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 11, 2005 Author Share Posted August 11, 2005 I found the hissing...it was actually a torn injector-manifold seal. That is fixed, but the gauge still hits the 0 pin on the wrong side. I'm definitely missing on 1 cylinder, and it won't idle. I suspect either the fuel pressure really is that high, or i need to do some tweeking on my MS... Quote Link to comment Share on other sites More sharing options...
pallnet Posted August 11, 2005 Share Posted August 11, 2005 Sounds like your fuel pressure is that high. Do you have a tester gauge you can plug into the feed line? That would tell the truth. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 11, 2005 Author Share Posted August 11, 2005 only type of tester i have is a compression tester... just by bending the 'to' line, i can make the gauge go up to about 5-9 psi... *EDIT* Just to clarify, I have the line from the fuel rail going to the port on the side of the fpr, and the return line is attached to the 90* bent port coming from the bottom of the fpr. Quote Link to comment Share on other sites More sharing options...
pallnet Posted August 11, 2005 Share Posted August 11, 2005 Go to the chat room. We can have quicker replies that way. Quote Link to comment Share on other sites More sharing options...
clint78z Posted August 11, 2005 Share Posted August 11, 2005 Thanks for clearing up a lot of questions, usually I wouldn't ask so many questions on a simple upgrade. However I am upgrading with your kit not only to increase output, but to eliminate a erratic problem I have currently. I want to get it 100% so I can elimante it as a problem and move on to further diagnosis. I will keep everyone updated on how it goes !! Quote Link to comment Share on other sites More sharing options...
pallnet Posted August 11, 2005 Share Posted August 11, 2005 Clint Your RX7 injectors are the later ones. You want to check but I don't think you have to bore out the holes in the manifold. If I remember correctly, those injectors have a smaller pintle setup like the stock Z injectors. Quote Link to comment Share on other sites More sharing options...
clint78z Posted August 11, 2005 Share Posted August 11, 2005 Quite sure you are right the pintle caps are 9mm on the later RX7 ones I have. I will have to re-verify, but I think that is same is the stock Z ones. Thanx a bunch !! C Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 12, 2005 Author Share Posted August 12, 2005 a little update... I changed out my fpr to another stock one...but the pressur still goes way past 60 when the motor is "running"...the differenc is, that with the old fpr, the pressure would drop to 0 after the pump was turned off. Now, with the newer stock one, the pressure falls to about 38 and stays there (according to the gauge). I bought another gauge from lowes, but I didn't get one of the fittings I need. I'll have to go back this afternoon for that so I can make sure the fuel rail gauge is working propely. *EDIT* It would make sense to me that the return line was clogged, but I know it's not because i unwittingly spilled about a gallon of fuel when I unhooked it. It was syphoning itself out while i was working on the fuel rail... Hmm...another thought... I recently got a new gas cap, and everytime i take it off now, a lot of air comes out like it was under high pressure. Could this prevent the fuel from re-entering the tank like it should? Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 12, 2005 Author Share Posted August 12, 2005 another update... With the new gauge and the gascap screwed on tight and unscrewed, it makes 80psi while running and holds at about 38psi when off... Quote Link to comment Share on other sites More sharing options...
clint78z Posted August 12, 2005 Share Posted August 12, 2005 You may have a clogged check valve in the return line, make sure you get a vented gas cap as well. Some good info at this website, part was pillaged from SDS website. http://www.robietherobot.com/storm/fuelinjectorguide.htm Quote Link to comment Share on other sites More sharing options...
pallnet Posted August 12, 2005 Share Posted August 12, 2005 Did you try disconnecting the return line in the engine bay (With the engine off). Removing the fuel cap and blowign the return line out with compressed air? You should hear it in the tank with the cap off. You may have set the gauge a little off when you messed with the set screw but still the pressure is too high. There is something in your return system building the pressure. After you find the problem and get it squared away then you can use your new cheapy gauge to reset the one that came with the rail. Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 12, 2005 Author Share Posted August 12, 2005 the gas cap that I got is the oem one, so i would assume it is what is supposed to be there? Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 12, 2005 Author Share Posted August 12, 2005 I'll try that...but all i have is a manual air pump... What do you think about the fpr? Quote Link to comment Share on other sites More sharing options...
Phyxius Posted August 12, 2005 Author Share Posted August 12, 2005 Problem solved. It was a case of 'the PO was a moron'. There was a rubber vacuum port block off jammed in the return line. When i first got the car, there was a 3/8 socket hose clamped to the return line as well. I removed that, but had no idea there was something inside the line. No wonder my old pump used to scream so loud! Quote Link to comment Share on other sites More sharing options...
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