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Engine won't stay ON after firing up - carburetor help?
Hello All, I tried searching for this info and but could not find anything.
I have a 1979 Rx7 with 12a engine, racing beat holley carb and intake, holley fuel pump and regulator, new fuel filter, stock ignition, removed rats nest, removed brake booster with delete kit (just to be able to stop temporarily), fuel cell installed to supply fuel because original gas tank is rusty.
The engine turns over and fires up quickly after pumping the gas 5 times or so, but shuts off immediately after releasing ignition switch. If i keep pumping the gas pedal, i can get it to stay on for about 5 seconds then it shuts off. The fuel seems to be reaching the carburetor just fine and fuel pressure is 4.5. when you pump the gas pedal it squirts into the intake but i don't think it continues to provide fuel after it turns over. I tried adjusting the floats, idle screw, speed screw and pump screw, but I could not find an rx7 specific tutorial so who knows now.
I am hoping to get this engine started and running to put it into another project (1978 JDM Rx7).
I am in Middletown NY and do not mind a helping hand if anyone is nearby.
I noticed the Holley on my 1979 Turbo Setup is flipped the other way, the throttle is toward the front of the motor and choke side is to the firewall... could this cause the problem? See picture above... is it correctly mounted? Does it matter?
Will choke adjustment be the issue?
could it be the float level?
in my experience, the orientation should be the other way with the primaries of the carb feeding the 2 inner ports. throttle cable connection pulls from the bottom of the throttle arm. but it should work either way.
The pic in post #6 is the correct orientation for a Holley on an NA motor, with the primaries (choke side) feeding the inner runners. Not sure about blo-thru turbos though.
Thank you... the turbo is running fine for now. Starts up quickly and car pulls nicely through the rpm range.
This one i cant get to stayt ON. Now I am having a hard time even getting it to turn ON for the couple seconds it was doing prior. I made the mistake of trying to adjust the metering screws to recommended starting positions 1.5 turns, and idle screw 1 turn. The float level, I can't seem to grasp the logic.
Float level, the primary bowl was not leaking out and seemed to be right where it needs to be, just about to pour out. the secondary bowl was too high so i lowered it and it seems to be fine now. Is there a starting point for this adjustment?
What will happen if the float level is to high vs too low?
I checked everything but that. New fuel pump, carburetor, intake, ignition coils, and I was just checking the compression and said to myself "check the condition of the spark plugs again, and they looked good" and then I was like "lets google the wire diagram". And bam... it was all wrong. Lol. Started up like a champ!
Btw, the choke needs to be dialed in to stay running, but that was easy to spot when observing the carburetor and seeing the choke plate open... once I closed it, it now runs. Time to fine tune it.
02-03-23, 05:46 PM
Engine won't stay ON after firing up - carburetor help?
