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-   -   85' RX7 isnt pulling fuel (https://www.rx7club.com/new-member-rx-7-technical-256/85-rx7-isnt-pulling-fuel-1033338/)

Mr.Monsoon 04-23-13 07:03 PM

85' RX7 isnt pulling fuel
 
I bought a 85' 12A yesterday, it started up, ran good, etc. I pulled the carbs to check jet size today (I'm 2000 ft. lower than where I bought the car), put the carbs back on, and it won't stay running. It will start up if I step on the gas pedal several times, runs for 6-10 seconds, and dies. It's all hooked up the way it came.
Help?

clykins 04-24-13 02:45 PM

Are the fuel bowls 1/2 full? Do you see any fuel coming out of the main discharge nozzles? If not I would pull the fuel supply line to the carb and do a fuel volume test. Make sure you hooked up the fuel supply and return line to the correct side of the carb. If nothing there, check the 20 amp fuse and the fuel pump cut relay. Does the fuel pump come on? I would also check your fuel filter while you're at it.

Also, if you haven't already, go to the 1st Gen section and under the stickies you will find "download your FSM". There is a lot of information on the carn and fuel system there for free.

diabolical1 04-24-13 03:36 PM

welcome to the board. :)

first let me ask a few questions.

you keep saying "carbs" so I just want to confirm that we are, indeed, dealing with more than one carb (twin Webers, maybe?). also, it might be relevant to include whatever current specs and/or jetting information you can.

does it idle normal for those 6 to 10 seconds?

Mr.Monsoon 04-25-13 11:01 AM

Sorry guys, I need to work on my lingo. I should say I have a single, double barrel weber IDF 40. It idles smooth for those few seconds its running. I can hear the fuel pump come on when I turn my power on, and I don't have a return line. New fuel filter. The fuel bowls were 1/2 to 2/3 full. I have some sort of fuel control solenoid. Fuel line runs from pump to solenoid, solenoid to carb. There is a brass T fitting coming off my intake mani with a small line to the solenoid, and another line to the manifold on top the carb (joins carb to turbo). Solenoid gauge states 7 psi when power is on.

Mr.Monsoon 04-25-13 11:02 AM

2 Attachment(s)
Some pics

Rotary Madman 04-25-13 01:40 PM

Hmm.. no return line? I'm not familiar with this setup but, I am guessing that your solenoid valve isn't keeping your bowl full or something is clogged.

Does this carb have a accelerator pump? maybe pumping the peddle is providing gas from the accelerator pump but the carb cant keep up afterwards.

Try starting it and continually jabbing the throttle. does that keep it running rough?

Do you think your issue is a lean? or rich issue?

are you flooding the engine?

diabolical1 04-25-13 10:43 PM

it appears to me that the "solenoid" you're referring to is actually your pressure regulator and if you're really running 7 pounds of pressure, then that's WAY too much. you'll need to dial that back down to the somewhere in the 3 to 5 range. i'm surprised the bloody thing starts at all at this point and isn't pissing fuel out of somewhere while running.


just an aside ... you may also want to consider moving the coils to another location - away from the fuel line.

Mr.Monsoon 04-26-13 11:45 PM

My issue is, the car ran when I got it. I pulled the carb to check jetting, put it back on, and it wouldn't run. I have a rebuild kit on the way so I'll get all new gaskets and jets in it and go from there.


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