This weekend I had a bit of a yikes moment. I finished putting the steering column back in my project fiat x1/9 and quickly tested the key still turned the ignition on and stuff.
So ignition goes on, I hear the familiar fuel pump sounds, see dash lights, all good. Then POP, clink clink clink, and the sound of fluid spilling. Hmm. Ignition off.
Well, there was a plug in this unused port on the fuel rail (used to supply fuel to the cold start injector, which no longer exists), but it shot out and this became a perfect little fountain of fuel in my engine bay. Yeah right onto the header. Luckily the engine was cold and not running. Luckily I was not actively driving the car, etc, etc.
Needless to say, I'd rather NOT repeat that particular failure mode. So I made a new plug which hopefully the rubber hose can grip better. Small plug was what came with car, bigger one is the one I just made. But I still don't love the solution. Help me upgrade.
- Should I get a hose barb to female NPT and then a male NPT plug? This would allow for easy fuel pressure checking if necessary.
- Maybe I should get a permanent fuel pressure gauge?
- Maybe I should get a fuel pressure sensor?
- Maybe I should weld something to the rail and eliminate the rubber altogether?
- Something else?
I think GM vehicles use a schraeder valve on the rail to connect a tester - which means there are a lot of tools out there for the same. I'd do that if you can find a way. Welding might be the most secure connection option.
Keith Tanner said:
I think GM vehicles use a schraeder valve on the rail to connect a tester - which means there are a lot of tools out there for the same. I'd do that.
I tried looking for that option a bit. I can't seem to find any schraeder valves that connect via hose barb. Am I not looking in the right places? But the NPT fitting should be common as well for connecting diagnostic gauges.
In reply to Robbie (Forum Supporter) :
I assume the clamp now goes on that groove? That's what I would try.
Years ago I replaced the fuel filter in my 60 Cadillac. I apparently didn't get the glass seated right. I started it up and then causally walked up front to see gas spilling all over the running engine. I think I set a speed record for getting back to the driver's seat to turn it off. This type filter.
In reply to Stampie :
Yeah the idea is that the groove gives the rubber hose something to key into.
Mr_Asa
PowerDork
4/11/22 11:38 a.m.
Is the rail steel or aluminum? How thick? Possibility of tapping it?
Pull the rubber off, put the plug in, then JB Weld over it to lock it into place?
Stampie said:
In reply to Robbie (Forum Supporter) :
I assume the clamp now goes on that groove? That's what I would try.
Years ago I replaced the fuel filter in my 60 Cadillac. I apparently didn't get the glass seated right. I started it up and then causally walked up front to see gas spilling all over the running engine. I think I set a speed record for getting back to the driver's seat to turn it off. This type filter.
BTDT, only it was a '66 :)
My most exciting version was having a brand new Russell adapter blow off on track. 60 psi fuel geyser on to a hot engine. As a bonus, the super genius (no, NOT me) who had programmed my ECU had turned off the fuel pump kill so the pump kept going after the fitting exploded even though the engine had died.
We got reports of a few others failing as well. Kids, don't use the aftermarket fittings with the plastic inserts (left) even if that's what the OEs use. The aftermarket screwed up the implementation. Use the two-piece aluminum version (right) that clamps on and cannot come off without being unscrewed.
In reply to Keith Tanner :
The left fitting used to be the only one you could get. I had one on my trans am for at least a decade. Oddly enough I heard that people were having issues with them getting blown off. Ordered the fitting on the right and then a few days later had the fuel geyser under hood. Luckily it was at the end of my street, with the engine still cold.
Coasted back home and swapped the fittings. I believe I even made it to work on time.
In reply to ian sane :
Yup, I was able to get one of the very first of the aluminum versions when they first went into production. I don't know why the plastic ones fail given that the OEs have them figured out, I'm assuming someone got a critical dimension not quite right.
Keith Tanner said:
Yup, I was able to get one of the very first of the aluminum versions when they first went into production. I don't know why the plastic ones fail given that the OEs have them figured out, I'm assuming someone got a critical dimension not quite right.
Perhaps the plastic clips don't have the right level of friction against the aluminum body the same way that they do with the common plastic ones?
Keith Tanner said:
Stampie said:
In reply to Robbie (Forum Supporter) :
I assume the clamp now goes on that groove? That's what I would try.
Years ago I replaced the fuel filter in my 60 Cadillac. I apparently didn't get the glass seated right. I started it up and then causally walked up front to see gas spilling all over the running engine. I think I set a speed record for getting back to the driver's seat to turn it off. This type filter.
BTDT, only it was a '66 :)
My most exciting version was having a brand new Russell adapter blow off on track. 60 psi fuel geyser on to a hot engine. As a bonus, the super genius (no, NOT me) who had programmed my ECU had turned off the fuel pump kill so the pump kept going after the fitting exploded even though the engine had died.
We got reports of a few others failing as well. Kids, don't use the aftermarket fittings with the plastic inserts (left) even if that's what the OEs use. The aftermarket screwed up the implementation. Use the two-piece aluminum version (right) that clamps on and cannot come off without being unscrewed.
I have had an all OE quick connect blow off. That was entertaining.
Anymore, I try to salvage things like the safety clips that Ford and Toyota use, for belt and suspenders. Or not use quick connects and just use high pressure fuel hose, for things that don't have to come apart.
So, it looks like my fuel pressure tester (which looks a heck of a lot like this one https://www.speedwaymotors.com/Performance-Tool-W80595-Fuel-Injection-Pressure-Tester,373404.html?sku=91080595&utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE&gclid=CjwKCAjwo8-SBhAlEiwAopc9W__va23mxTlZ-Rj6ZNml6w_zOUEbycZkv-Kf5TT_MFWLgRl4SwX9RBoCtiUQAvD_BwE) has both the schraeder fitting and a female NPT -4 fitting to connect to a fuel rail.
The gauge itself looks like 1/4 NPT though I didn't take it off of the test hose.
I may already have a hose barb to AN -4 fitting somewhere in the shop. Then I would just need an AN -4 cap.
Robbie (Forum Supporter) said:
Keith Tanner said:
I think GM vehicles use a schraeder valve on the rail to connect a tester - which means there are a lot of tools out there for the same. I'd do that.
I tried looking for that option a bit. I can't seem to find any schraeder valves that connect via hose barb. Am I not looking in the right places? But the NPT fitting should be common as well for connecting diagnostic gauges.
I've used this 1/8" NPT test port on a couple different vehicles and it's held up great: https://www.riffraffdiesel.com/replacement-schrader-valve-fuel-injection-rated-1-8-npt/. I'd screw one of those into a 1/8" NPT barb adapter for a quick and easy fix.
In reply to obsolete :
yeah I was a little worried about the core itself not being fuel rated. I did already go ahead and order the hose barb to schraeder that I linked earlier, but I think I should be able to replace the valve core with a fuel rated one if it doesn't work.
In reply to Pete. (l33t FS) :
When you're hooking a fuel line to a modern fuel rail, you usually need some sort of adapter. Replacing a factory quick connector with just a hose and hose clamp doesn't work because there's no flare to prevent it from being pushed off. The adapters in my picture convert the smooth hard line to an AN fitting so a nice braided hose could be used.
In reply to Keith Tanner :
True.
OTOH, part of the fuel system in my Mazda is GM type plastic quick connect fittings with rubber fuel hose clamped on instead of push-on plastic line. Fuel rail is converted to hose barbs, too, the quick connects are at the fuel filter.
I don't much like braided hose 
You can get quick connect to hose barb adapters, I assume that's what you're using.
Am I off base to think sweating a slug of copper/aluminum/steel/ whatever in there is a good solution?
I think plumbing solder could hold the what 30 Psi your fuel system would run.
wheelsmithy (Joe-with-an-L) said:
I think plumbing solder could hold the what 30 Psi your fuel system would run.
I don't think soldering is a good idea in an application with a lot of vibration like an engine.
(Also, dunno about X1/9s specifically, but most fuel injection systems are 40-60 psi.)
Perhaps brazing would work, I don't know much about that process.
In reply to Keith Tanner :
Big thanks for this advice. I was about to hook up one of these style connects on my truck tonight. Saw this and ordered the fittings on the right instead.
For all who wish to do a permanent seal to this port you are overlooking the fuel sampling port requirement in many sanctioning bodies. The Schrader valve meets this easily.
Yeah, I think I mentioned it but for now the plan is Schrader because of easy pressure testing and it also fixes the problem. And it's cheap. Win win win.
Oh, and if nitrous needs to be added later simply remove Schrader. Win again.
Well, it sure got here quickly. The 1/4 inch barb is a little small to be ideal, but the hose clamp worked.
And just for kicks I went ahead and measured fuel pressure because I can.
Cool.
