So what you need to do is get a EFI fuel tank our part number GT-425, then the fuel pump module GT-421 and the sending unit GT-424. You will also need the new neck item GT-296 along with SF-339 which are the fastners. Then you can get rid of that canister thing that mechanical fuel pump and have a real pump in the tank with volume of fuel to keep it cool. Once you get this call me and I can explain how to plumb all of it for you to make it super reliable.

 

Are you positive that even though those parts are advertised for up to '74, they will work in a '77 as well, Justin? Thank you!

 

Well I'm going to have to find out what my problem is before I try to fix it. I appreciate the options and would have loved to get that $250 tank/pump set up, but that's where the saying, "The early bird gets the worm" comes from or is it, "You snooze You loose"? Either way $600 for a new tank and EFI pump set up, isn't in the budget at this time. Never know when a bike sells, the budget may change. I'm sure I can recoup the cost by selling the fcc and inline pump afterwards.

 

100% this is what we use when doing them. We have our 76 here setup right now and if you were in Carlisle it was the white one under the tent. You could also modify your original sending unit to mount an electric pump on it and use that and your original tank if you wanted. Either way will work. The return line is not big enough on your original tank so you will have to modify that. We also remove the factory fuel lines and run new -6 AN line down the frame.

 

You can easily make your stock tank and sending unit work. You will just have to modify the sending unit. You are going to have to get a bigger return line, and adapt the walbro 255 pump to sending unit. You can drill a small hole and run wires through it but they make bulk heads as well and I would use one of those.

 

I got a little time to see what was going on. The fcc gauges read 2 1/2 - 3 psi on the low pressure and 40 on the high. Bringing the the rpms up to 1800 - 2000 rpm brought the low up to 4 1/2 psi and the high remained at 40 psi. Running it like that for about a minute I saw the high pressure jump up to near 60, then the low pressure started dropping along with the high. I could feel the engine start to starve as the low was near zero and the high dropped down to 20 psi to zero. I also noticed that while I was running it at 1800 rpm the front and rear header pipes on the pass side were glowing, With a bike, I would interpret to mean those two are running lean, but with a V8 I'm not sure why outside two would cherry up and not the center two.

I jacked up the passenger side to take a look at the fuel line and it runs from the pump between the oil pan and the header. I'm not sure that it was close enough the get heated to the point of vaporizing the fuel, but by watching the gauges on the fcc, it makes me wonder if that is what is happening.

I also checked to see where the vent line from the fcc went and it looks to be plumed to the charcoal canister line, but not the canister itself.

 

Maybe put a heat shielding sleeve around the fuel line in that area to see if that has an effect.

Wow! Thanks for the info Justin. I'll have to sleep over that & decide whether I want to go that route. I suppose you run two -6 AN lines down the frame for the supply and return.

 

I would disconnect the vent line and run it (safely of course) into a container - this will tell you if you have a venting issue - if you have no problem when running that way you will know that you need to improve your vent line back to the tank. It will also tell you if the fcc has been modified or not. Based on the results troubleshoot from there.

 

No, I run one line and no return, I put my regulator in the back right by the tank and then my line always stays at 58psi.

 

Didn't get much done on the FI Tech system, since I posted last. It has gone completely to where the engine doesn't even start and zero pressure one the low pressure gauge on the FCC. I picked up a real cheap Edelbrock 1721 fuel pump($50) to see if that helps, but the low pressure gauge is still reading zero. Unplugged the low line and crank it and the pump is pumping like I think it should. The canister looks full and I can hear the electric pump energizing when I turn the key. I decided to unhook the high line at the throttle body to see what the flow looked like there. It's pumping also, but without a pressure gauge I'm not sure at what level it's at. I hooked the line back up to the TB, turned the key and it started right away, but shortly died again acting like it was out of fuel. If I disconnect the low line, fuel sprays from the pressure that's built up from the mechanical pump. IDK, it has me stumped.


So I decided to remove the throttle body and put a Carter quad I've had stashed out in my parents barn on it this past weekend. I zip tied the throttle body onto the FCC just to keep it out of the way. I got some fittings and fuel line hooked up and fired it up and is running great. Well I ran the car around the neighborhood and it seems to run pretty good as is, but it needs more miles to be sure.

I wanted to go to the Carlisle event in Lakeland this weekend, but I haven't had the time to do enough testing. That and I had teeth implant surgery Tuesday and my face looks like a puffer fish. I also need to finish the removal of the throttle body and the harness, but my mouth hurts too much to be climbing under the car right now.

I think I'll put the TB back on eventually when I can do it right without the FCC. Right now, I've had the car for almost three months and haven't really been able to take a 30 minute ride yet without a break down. I just want to enjoy the car for a while as it is. Maybe I can get one of my boys under there and disconnect the O2 sensors and I can sneak out for a little trip around the block while I'm off work recuperating. Just bending over to hook up the fuel line made my head throb.

Does anyone know if the FCC can be taken apart or sent back to FI Tech to have it checked out? What concerns me the most, was the zero pressure reading on the low pressure gauge when I believe both mechanical pumps work.

 

I'm not 100% certain, but I think you have an issue with your vent line. Have you tried disconnecting the vent line and running it into a container while starting and running the car as I suggested?

 

No, I forgot to try that. It's been a rough month, my father passed on the 1st and things have been a little busy. I did look under the car last month and the canister behind the right front fender well isn't even connected to it. I'm guessing it was at one time. The vent line from the FCC runs behind the engine to the hard line that I believe went to that canister. This new fuel pump doesn't have a vent connection, so I guess I could run the FCC vent line to the hard line that was running to the OEM pump?

 

Edelbrock has a standalone system also not sure if it has the same problems as your other one. Edelbrock Universal EFI Sump Fuel Systems 36032

 

Sorry to hear you've had a rough month.

My vent line is teed and runs both to the return line from the pump, and the line from the charcoal canister (which is the one yours is hooked to), but I believe if you're going to do one or the other then the pump return line is the better option.

 

Thanks Mh, I may hook it all back up and try the vent line like you suggested. It is a simple swap and can swap it all out in an hour. I'm not going to make down to the Carlisle Lakeland event anyway. Maybe I'll have her ready for next year. What should I expect? A gusher, steady stream, trickle or nothing?

I like the stance of your Vette in your avitar. Mine is a little too high right now, but the suspension is fresh, so I'm going to wait till I put some miles on it to see how it settles in, before trying any mods.

 

If the fcc is unmodified then there should be little to no fuel coming out of the vent, but by having it flowing freely it may solve your problems if your current problem is the vent line as I suspect. If the fcc is modified then there should be a fairly consistent flow of fuel out of the vent. Again, if your current vent line isn't flowing freely, then flowing it into a container should solve the problem. So you get two advantages from doing the test - you test your vent line, but you also determine whether or not your fcc is modified.

 

The PO said he did some mod to it that was suppose to help, but I don't know what that was and apparently it didn't help.

 

It won't have helped if the vent line isn't flowing freely back to the tank. I don't recall if we discussed previously, did you adjust the pwm settings as per fitech instructions for the fcc? They need to be adjusted lower than default. The mod is to remove the float so that fuel flows through the tank and out the vent, circulating to keep it cool.

 

What is pwm? Also can the FCC be opened. I was just looking at an online instructions for installing the system and it says it needs a filter between the mech pump and the FCC. This one doesn't have one, only the filter between the FCC and the TB.
https://fitechefi.com/wp-content/upl...ons1.11.18.pdf
I'll look for instructions on setting it up and go from scratch.

 

Pwm settings: https://www.google.com/url?sa=t&sour...mbg7FrenvjpNIc

Yes, you should have a pre-filter, I have one filter between the mechanical pump and the fcc, and another between the fcc and the throttle body.