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-   -   What size fuel pump for a carbed fc? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/what-size-fuel-pump-carbed-fc-42356/)

chris_stampe 01-02-02 12:04 PM

What size fuel pump for a carbed fc?
 
My fuel pump blew last weekend. (probably because the previous owner was trying to run the stock fuel pump with a 2 double barrel carb setup he put in in place of the fi system) I would hear the pump ticking then all of the sudden it stopped--well almost stopped, now i can hear a very very faint ticking when i put my head in the back above the pump. I am wondering what size fuel pump i should get for the carberetor system i have. Its a cartech 2c turbo (w/o turbo, but will have soon hopefully) It is 2 2bbls. i am told that most carbs run at like 4-6psi and fi runs at what like 20-40? I dont know for sure. I was just wondering what you guys would recomend i buy to replace the blown pump. Thanks!

Scott 89t2 01-02-02 12:11 PM

you need to use a carb fuel pump. they run way less like you said. a pump will flow way more fuel at 4psi then at 40 so you don´t need a ¨huge¨ pump.

chris_stampe 01-02-02 10:06 PM

do you think that a pump from a 1st gen would fit in my car? and if it would, would it pump adaquit fuel to my carbs?

HWO 01-02-02 11:05 PM

something that flows similar to a holley blue

pp13bnos 01-02-02 11:09 PM

No a stock 1st gen fuel pump wont cut it. Spend the $$ and go out and buy a mallory 110gph fuel pump. Next, replace the stock pickup tube with a 1/2 pipe and line all the way to the fuel pump. After the fuel pump, run atleast 3/8, all the way to the regulator/motor. This setup should be good for atleast 350hp. Rob at Pineapple (I also did) uses this on his own peripheral port engine, that cranked out around 340hp. Even at this hp level, he had less than 1/4psi drop over the entire rpm range.

In my life i've owned two 110 holleys, and one mallory 110. The holleys suck, plain and simple. They are lound, and don't take vibration very well. On bolth units, the magnets have seperated from the housing. Causing the fuel pump to not pump very much, and make very funny noises. The mallory is so quite, you can barely hear it. You also want to rubber mount your fuel pump to help keep it quite.

Holley sucks, and mallorys are over priced. CJ

chris_stampe 01-04-02 11:17 AM

where is the fuel pressure regulator on most fcs?

FPrep2ndGenRX7 01-04-02 12:29 PM

Its on the fuel rail under the factory intake but if you running two carbs you shouldn't have to worry about that. That regulator is for fuel injection and can't be used for a carb besides the fact its made on the end of the fuel rail. You need to add a fuel pressure regulator just before the carbs. Depending on your carbs you can change the pressure and get better performance from them. You wouldn't believe the difference 1 psi can make on a carb. It can be used to help fine tune your carbs.


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