This is a pic of currently installed rail and hold down setup for reference.

Everything was fine. I replaced the clifford headers with dutra duals. The intake I took apart as an assembly, I did not separate the injectors/rail. Ran fine in driveway before taking to shop. Started in shop after job was done, regulator was leaking. Tightened regulator top/bottom halves together, everything ok. Drove the car ~250 miles without incident.

Come to fill up gas one day... when leaving gas station car popped as if it had a small backfire - hasn't done that since its carb days, however figured it was slightly warmer, may of let go of the starter key a tad too soon, no big deal. One or two turns out of the station and I smell fuel. Window was down, figured I spilt some on side of fender. Once I get home, fuel smell still there and strong - open hood, and whoa! Injector #5 & 6, the top o-ring is exposed, partly came out of the rail. Steady fuel drip evident. Thankfully no fire. Usually fuel system maintains pressure after shutoff for probably an hour - gauge read almost zero by time I got out of car and opened hood.

I didn't do much to it for fear of any more leaky fuel while it was still hot. The brackets and rail were snug, nothing loose. Apparently the pop I heard was the o-rings coming off.

Any ideas? Could a restriction in the line or a pump that went on crack and output way too much pressure cause the o-rings to become unseated? I suppose its plausible but I figure if that were the case it would be well past the point of engine dieing because it would be ultra-rich. Drove across town from station to home without incident... Maybe exhaust guy leaned on rail and cause brackets to tweak and now I see evidence of it? Just suspicious it only happened after 250 miles, and also only to last 2 injectors (on input side of rail). The others look normal.

I was never very fond of that fuel rail but it never gave me problems. The part that fits over the top of the injectors isn't very deep as seen here however it never gave me an issue in over 20k miles I put on this setup so far. The pump is noisy and on its way out however was maintaining pressure fine.

Once I get the chance I plan on reassembling everything and running the pump alone to see whats what.

The cups on the rail, where you stick the injectors, look like gm ones.
Maybe you could use the little clips the gm's use to hold the injector in the rail?

I have seen them on bmw's and other bosch systems too.

They look like this:

Your fuel rail hold downs aren't very strong. You're relying on bent aluminum to not un-bend to hold the fuel rail in place. I would make two little triangles of aluminum and weld them into the open side of each fuel rail bracket. That way you aren't loading the bend in the aluminum, but the gusset on the side of the bracket.

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Joshua

What is the blue thing attached to the TB adapter?

Sam

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Accufab universal model adjustable rebuildable fuel pressure regulator. Adjustment screw and vacuum feed is on opposite face that the pics don't show. Think I have more pix of it on my efi install thread in the gallery.

AH, Thanks. I should have figured that out. Is that a cable AT kickdown? It kind of looks like a cruise control. But, that seems kind of unlikely.

Sam

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Sad to say I don't know how to drive a stick its the 904 lokar kickdown kit and throttle cable.

Pierre, my fuel rail losses pressure pretty quickly when I shut off the key, even though the pressure regulator has been replaced. I guess it must leak down on one of the injectors. How can I find out which one? I sent them all to ACcel for flow testing, and did not mention my suspicions at that time. There are no visible leaks in the rail or connections anywhere.

Sam

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Bypass the rail, run the pump to the regulator to the return to the tank, then power up the pump. That would eliminate the injectors all together.

Only way to eliminate one injector vs other is to hook the rail back up but have the injectors pointed into a bin or some other container and observe for any fuel coming out of the pintle side. Leave the injectors unplugged, but you'll have to use those clips to secure them to the rail so the input pressure doesn't send them flying. Or maybe just pull the intake off as an assembly with rail/injectors.

Last variable is the pump itself, maybe your pump wasn't designed to hold pressure after shutdown?

I seem to recall this topic before and I thought you said the new regulator fixed it. Then again I'm not so sure its a problem as long as the system maintains pressure with the pump running. Only thing I can envision is startup issues after shutdown, but you shouldn't be relying on pressure from the past start, the computer should prime the pump the second its turned on (before cranking) for a brief moment.

I've called Rance at rancefi.com and sent him pictures, lets see what it will cost for new rail/holddowns. Years ago he quoted me 400 but that included bosses as well, which I don't need since they are on my clifford manifold already.

YOu recall correctly. It was an issue, and a new regulator took care of whtever symptom I was bothered by at the time. I am still working with the strangely variable start up behavior. One time it wants a prime, and the next time it doesn't. One time it fires right up, and the next it takes several crank cycles (crank, no crank, wait a few seconds is one cycle), before it will start. It has never failed to start eventually, but it is not something I can point to with pride when showing the car off.

Do you feel like you can communicate well with Rance? Does he always answer his e-mail? He would fail to answer my e-mails and I never knew if he was just blowing me off, or not getting his e-mails from me. Being an impatient guy, I would get frustrated, which strained our communication when I did get ahold of him.

When I was trying to get the car started the first time with the Accel ECU, almost from the start he said, "just send the stuff back, and I'll return your money". He assumed I was blalming him for things going wrong, which was not the case. I just needed some guidance. It all revolved around the wiring of the Mopar distributor to the Accel ignition harness. As it turned out there was an initial problem with the ECU which Accel fixed, but I took it elsewhere for that. I think he was glad when I drifted away from him. He never did answer My last e-mail to him. Sometimes two people can get off on the wrong foot, and never get back, even with the best of intentions. It has always made me feel bad that I could not keep things going with Rance, because I really liked him.

Sam

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Does the unit have a electric fuel pressure sensor? Maybe it won't prime if the pressure is already high enough? Interms of startup behavior the system only needs to hold pressure with pump off long enough between the time from start to crank position of the key.

Took me a couple of tries to get him on the phone vs his machine, then I sent him an email for pictures. No response yet but hasn't been a day even - his website says give him 48 hours to respond to email so I figure if I don't hear from him next week I'll call him back. Friendly guy so far.

I kind of suspect that maybe the surge tank is part of the problem. It can get a little low when it sits ofr a period of time, and then maybe the pickup for the electric fuel pump is variable as a result. The extra cranking may be just to fill the surge tank, which is done by the mechanical pump. When I get the new tank in, that will no longer be an issue. Do you still want me to take a photo of the pump and send it to you? I have it out now.

Sam

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Yea I would like to take a peek at the pump and in tank - I'm trying to see what the money gets - I may wanna use this as an excuse to buy myself a tig

I'll take photos tomorrow evening, and send them along to you.

Sam

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what pressure you get to if you dead head it. i couldnt imagine it poopin off if your only runnin about 20 for that throttle body.
and the pressure bleedin off right away could be the fuelpump check valve... i knew a chick wit a honda that had dat prob

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'72 Valiant DD for over a decade-225-Disc brakes, big T-bars, big Sway bars f/r, carter bbd/super six, GM HEI, 2- 12" subs in trunk, 1000w amp...
'77 cherokee cheif widetrack-360-33x12.5 tires-no lift. keeps driveway dry-project/backup DD/mudder