Rick's tank with Vaporworx

[1bad68cat]

Hello everyone,

Just wanted to get some suggestions as to what to look for. I purchased the aforementioned tank for my 66 c10 and ran into a small problem (hopefully). I have not dropped the tank yet to see what is wrong, but plan to this weekend. Just to give you an idea of the problem, the truck acted like it ran out of gas even though it is half full. After I got it towed home, I was able to start it again, but it did not run right. I backed it into the driveway and it began to run normal. I was afraid if I took it out for a spin, it would have quit working again. I checked the easy stuff, fuse, relay, wiring etc. but did not find anything unusual. I had driven the truck with the new fuel system for a couple of months and even towed a car home with it. When I drop the tank, what should I look for that may not be obvious.

Thanks in advance,

Robert

[Chevydon]

Check if the fuel vent line is clogged as it would cause line to vacuum shut. Also run a test light to the dash connected directly to the tank. Last one run a fuel pressure gauge with a long hose to under the wiper blade to watch as you drive and the not normal condition happens. These are a few tricks I know with fuel systems and efi.

[CarlC]

Robert,

I agree with Chevydon. A fuel pressure gauge will help narrow down if there is a fuel delivery problem. I suggest doing this before dropping the tank. Watch the fuel pressure and note how it changes while the engine is running.

Removing or loosening the fuel cap can also help uncover a deficiency in the venting system.

If you find that there is low fuel pressure but the pump sounds like it's running fast then perhaps the fuel pressure regulator on the base of the fuel module has become dislodged. If the retaining wire has come off or the o-rings displaced then insufficient fuel pressure will be made. There should be three o-rings. One that surrounds the base of the regulator (approximately 1" dia.), another that seats on the 1/8" diameter return tube on the regulator, and the third in the fuel pressure regulator adapter O.D? groove. The return tube should not be confused with the vaccum line nipple.

The LS3 modules have proven to be very reliable. So far there have been no "normal" failures that I am aware of.

Please keep posting your findings. I'll check in when I can to follow-up. If you need to talk PM me your phone number.

[1bad68cat]

Thanks everyone for the replies. I'll definitely check fuel pressure before dropping the tank. I also talked to Hector at Rick's and he said to check the harness going to the pump. He stated he did have one customer have an issue with the harness even though everything pointed to the pump. I'm really hoping it is something simple.

[1bad68cat]

So I did a fuel pressure test today. I am only getting 20 psi at the fuel rail. Increasing engine speed has no affect. Also, after shutting the truck down, pressure does not hold. If I'm not mistaken, it's suppose to for a short time. There are no leaks in the fuel lines coming from the tank to the fuel rail so I'm expecting there's a leak internal to the tank. Which places should I look and is there a way to bench top test the assembly?

[1bad68cat]

UPDATE: I dropped the tank and found that the fuel is leaking pass the o-rings on the regulator. Will I be able to pick up the O-rings at the parts store?

[CarlC]

The large o-ring or the smaller? I don't know if they offer replacements. I doubt it.

Have any photos?

[1bad68cat]

Hello Carl,

Sorry about that. I thought I updated this thread also, but I guess it was just Lateral-g. The problem was the regulator managed to wiggle its way pass the retaining clip. The oring was fine. I reinstalled the regulator and reshaped the retaining clip to hug the regulator body better. Thanks for the help.

[CarlC]

No worries. I just wanted to make sure you got it worked out.

Squeezing the ends of the retaining clip should keep things in place. It also helps seat the clip in to the module.