Hi, recently i had posted a thread on which i thought, still kinda do that it is a fuel issue, i just dont know, Here is what it does, truck will be going up a hill or whatever and will downshift into second gear, it will get up to about 4200 rpms and start to cut out right before it shifts, falls flat on its face, it is a 460, with the hot fuel system. The new parts are as follows( engine, transmission, edelbrock 750 carb, performer intake, electric pumps in tank selector valve, regulator, coil, distributor cap and rotor, wires, plugs, ignition box. Just about everything is new, i am getting 3.5 psi at the carb with fuel, pumps are getting 12 volts at the pump, inertia switch is good along with fuel pump relay also fuel tank switch is good working condition. What else do you need to know? i just cant figure it out and i really dont want to take it to a repair shop out here as it has a 73 crate motor, with none of the smog crap on it, and no smog stuff at all on the engine, ANY IDEAS?????

 

Can you rig up your fuel pressure gauge with a long hose and tape it to the windshield so you can take a test drive? I have done that before with suspected fuel problems.

 

yea i also put it in the windshield, and i put it in gear and powerbraked it and it will drop to about 2 to 2.5 but it drops pretty quick. still new pumps, either tank throws the same.....

 

Maybe it's just me but that fuel pressure seems low. Don't most carb system fuel pumps put out 6-7 psi fuel pressure?

 

I would take it out on the road. The engine is going to run ok on the fuel that is stored in in the carb bowel. If you have an extended heavy fuel use, and the fuel system get's behind, that's when it will finally use all the fuel in the carb, and start starving out.

Do you have the original return line fitting going into the carb? I believe it had a fitting up there with a fixed orifice that let some of the fuel return, and some of it go to the carb. If you don't have this fitting, the balance may be wrong between the amount of fuel returned, and the amount going into the carb.

 

yes i have that and i even had it replaced with the one that edelbrock calls for with thr .040 orfice..... what else would b causing my fuel starvation, what should i get exactly for pressure with this truck, what should i volt test, ie pumps selector, and how many folts should i get, pretty much what do u guys think i am missing, some of this stuff i have already done, but ill do it again, to refresh my mind, and cancel it out as the cause, this problem has been here for a month, the truck did run fine, then one day all of the sudden bam, selector valve broke truck stopped running fixed that it ran again couple miles later noticed the regulator leaking, and i replaced that too. ever since those two things, nothing but trouble so i dont know if i had a wire break somewhere, or an issue with something else im just completly stuck AHHHH

 

My guess would be something in or around the two things that were recently changed -
selector valve & regulator - is causing your problem. It was working fine, those two things
were changed and now it's NOT working fine, well, ideally, you'd change those things back
to how they were (but you obviously can't do that).

 

I agree. The first thing you could try is go back to the valve and pinch the lines off with vise grips to minimze the mess, and re-route the lines to run just on one thank, bypassing the valve, and try that.

 

i agree and disagree at the same time, i run the same pressure at the pump as i do at the carb, to me it seems more like its gonna be electrically something wrong with the truck, i will try your solution this weekend, the ford garage wont work on it cuz they dont have mechs that even know where to begin to touch a edelbrock and it has no smog equipment and it has a 73 motor, they are to picky about it being stock, well i hate it when they are stock. i like a little more power and the 73 motor did just that with the edelbrock, what about distribution? what should i check there?

 

My 460 did this for years after I swapped it to the Edelbrock(1411 Electric Choke 750,) the higher the gear, the lower in the rpm's it would do it, to the point that it would start to suck the bowls dry at 2500 under WOT in 4th gear, I finally solved it this past summer, I tried swapping it to the proper regulator Edelbrock speced, and I think it might even have gotten worse.
Just for the sake of trying it, I decided to just bypass it and see what happened, it runs like it should, but, the real weird thing is that while it always kept the filter full at idle before, now you can barely see any fuel in the filter at all, but, it runs fine. I think getting rid of that in tank pump is going to be part of this years coming mods, as the tank is leaking when full now anyway. I'm either going to stick a mechanical pump on there, or an external and a pressure regulator.

 

ok i could see that causing it then, when you bypassed it did it still run fine, i did get the one that edelbrock called for little **** was 50 bucks, so the next one is coming from a salvage yard, ill try to find an original one and see if that fixes the original issue since mine was only leaking, i really hate how ford has a one year extrodinary idea that must come from real extrodinary helmet wearing people if you know what i mean

 

It only runs properly with it completely bypassed. Both the stock one and the one Edelbrock speced didn't help my case at all.
I was actually lucky enough to score mine on e-bay quite a while back for $14 or so, but, it didn't do any bloody good... LOL

 

that seems about right-2 psi is way low!

 

delete, I saw someone else said what I was thinking.

 

New to this forum, but I am having the same issue, now armed with this info I will see what happens....