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Engine Specific Info and Questions => IDI Engine => Topic started by: Spokerider on September 29, 2018, 12:33:20 pm
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I had the little rubber nipple come off while driving the aaz the other day, By the time I realized there was a fuel leak, like 30 seconds...., the whole engine was bathed in diesel. What a mess. That was a brand new nipple the vw stealership charged me $6 for. I figure thats about $600 per lb for those caps....... ::)
Anyway, I don't want a repeat of that fuel leak. I don't trust the ribber caps now.
What about doing away with the rubber cap altogether? Why not run a plastic T in the first fuel return hose going to the second injector, and with a short piece of hose, connect the nipple that had the cap on it, to the short hose, and connect it to the T......essentially tying both nipples from injector number one, to the second injector. Any reason why this would not work?
Also.....does return-line fuel pressure go up with engine / pump rpm? Or is it at a constant pressure?
Thanks for your thots.
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If everything is correct, there is no pressure at all in the return line or the little jumpers between injectors. The only issue I can think of to cause pressure in any of those lines is a blockage in the line.
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No reason It wouldn't work. I run a tee between the hose from the first nipple on the #1 injector to the far nipple on the #4 cylinder and then from that tee send the fuel to the Out bolt. I put small width Zip ties on the tee and hose connections. Just takes a tee and a longer piece of hose to get from #4 to somewhere near #2 or 3.
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Thanks for the replies guys.
The fuel return leaving the pump seems to go back to the tank without any obstructing problem. All new inj. bleeding hoses installed too.
I have my spare rubber cap on the nipple now. Also used a small zip tie at the base of the rubber cap......if it lets go, I'll do a "T" mod. Hope it won't let go, as it was one heck of a mess!
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I find it odd that much fuel is excess to what it takes to fire the cylinder. If one is off it does seem to pour all over the place and takes forever to clean it up.
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stainless T 1/4"-1/8"
mcmaster or Zoro
(https://i.imgur.com/pxBgOTAl.jpg)
(https://i.imgur.com/4D1Oi6nl.jpg)
good quality poly fuel line makes excellent caps for injectors, vacuum, etc. ; just cut a short piece, melt one end a little and press it in vice to cool.
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Thanks for the replies guys.
I installed the second nipple with a zip tie, and so far it's staying put.
I made two more up for spares, with a short piece of hose and a bit of nail jammed in the end for a cap, so to speak.
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a good line with a stainless ball inside and a screw is what is holding more for me...
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There should be zero pressure on those lines and the rubber nipple. If you need to use zip ties or any other means to get a reasonable condition hose to stay on without leaking then there is a more significant issue to be address. There is some sort of restriction in the return line to the tank. If you bandaid with zip ties or hose clamps or without addressing whatever is preventing zero pressure fuel return, you run a greater risk of springing a leak in the return line or even in the pump seals. I've been there and it was no fun chasing injection pump leaks when the issue was the return to the tank.
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You could also have excessively worn injectors pushing too much fuel out the returns. Remove the return lines between the injectors and observe how much fuel is coming out. If you have extra line you could rig something up to go into catch containers to measure it and avoid a mess.
Also, are you sure you have an out bolt in the out port of the pump?
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Maybe by chance the little tiny screen on the out bolt itself it fouled up and not letting fuel return correctly? I have cleaned a few goobs of goo off of that screen once in a while. Not sure where it comes from, maybe inside the hoses between injectors?
It takes a good sunshine day to look at it and see if there is anything stuck on there. You might just float it in some paint thinner for a while and try blowing it out from the inside out. Hey OUT the OUT BOLT!
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The return fuel from the injectors does not pass through the out bolt/screen. It just passes into the banjo fitting around the out bolt.
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Some decent hose with a suitable ball bearing zip tied in place. Glad you spotted it in 30 seconds, me? only when I ran out of a full (£60) tank of fuel 30 miles later >:( There must have been many unhappy motorcyclists. :o