i installed a weber 40dcoe carb, intake, header, exhaust. all things are well and running good but on long pulls its falling on its face in top of 3rd and 4th. like its running out of fuel. im running the stock fuel pump with a mr gasket regulator and gauge. is the stock pump just not putting out enough? the regulator didnt have a fitting for a return line so i just put a t fitting in before it for the fuel return line. did i do this wrong? any suggestions are welcome. and if i need a better fuel pump do i just install an in line one or do i need a new one in the tank? thanks

 

i think your return thing is wrong, the regulator should do the returning.

what is your pressure set at? where is the gauge? gauge should be as close to the carb as possible.

 

ok coming from hard fuel line on firewall i have my main fuel line. there is a T fitting with the nipple having the return line on it. the fuel line then goes into the regulator(that does not have a return fitting on it for a return line) then i have the gauge then a 6 inch piece of fuel line running to the weber carb. im running 3 psi to 3.5 psi on the gauge no matter if i set it at 3.5 psi or higher. it will not go any higher. it might be that i just have it connected to the T fitting? what will it hurt if i just dont use a return line and plug it?

 

does the fuel pressure drop @high rpm?

if you have a returnless regulator, then the car should be returnless, try it, it won't hurt anything

 

I think webers need a higher fuel pressure than the Nikki, more like 5psi? Regardless it sounds like you need a better fuel pump

 

Webers like 4.5 to 5.5 psi.

stock RX-7 is only about 3 psi

 

Not only is the stock pump not up to the required flow and psi for the carbs
but the Mr Gasket regulator sucks *** and will not flow well and isn't very accurate.

I know, I have a Dell and tried one before and it caused exactly the issue you
described. The car ran fien without it but I wanted to put it on there to make sure
the pressure stayed put and it started running really bad. Removed it and it ran
great again.

 

You're not actually supposed to run more than 3.5 PSI with a Weber as per the service manual. Some people, myself included, run more than that without issues, but the stock pump is high enough pressure. Problem is that it's nowhere near high enough flow, which is why you're running the float bowl dry in the higher gears. You need a bigger fuel pump. I'm a fan of Carter pumps.

 

thanks.. yall have been helpful and this crappy mr gasket stuff definately felt and looked cheap. i still have the boxes so maybe i can clean them up and bring them back for a lil deposite on a carter fuel pump and regulator..... i havent messed with them so heres a noob question. i just hook up the carter somewhere along the framerail inline with the fuel line? and leave the stock pump in the tank? sorry if this is such a simple question

 

hooked fuel line straight from firewall and didnt use regulator, gauge, or return line. more power, no stumbles, pulls to 8k rpm and doesnt fall on face. looks like autozone is getting their mr gasket junk back lol

 

See, Mr Gasket sucks. Glad you got it going.