Primaries fueling unevenly, hard starting, surge.
Primaries fueling unevenly, hard starting, surge.
I drive an 87 Camaro Berlinetta with a 305 4bl electric carb with electric choke. For some time now I have been having problems with the idle surging during closed loop operation. And when I shut the car off, a lot of the times it won’t start for up to thirty minutes, longer if it’s really hot outside. All the ignition components either checked out or have been replaced if bad, mainly dist cap, rotor, wires, plugs. The spark module is fine, along with the pickup coil, and coil (off cap coil). What I have noticed is that when facing the car and looking down into the primaries the left jet is dripping slowly and the right one is completely dry at idle. When I throttle it up I then see two even sprays from both jets, then the rpms steadily drop back down then bog and surge back up. While this is happening I can see the fuel flowing but it doesn’t seem right. Can somebody tell me what is wrong here and how to fix it?
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Joined: Jan 2000
Posts: 20,981
Likes: 11
From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: Primaries fueling unevenly, hard starting, surge.
The jets that you see fuel squirting from when you open the throttle are the accelerator pump jets. You shouldn't see any fuel coming from them at all during idle. Down inside the primary bores are the boosters and inside them are the main discharge ports, you shouldn't see fuel coming from them at idle either. If you do see fuel dripping, you're flooding. Check the needle and seat for any debris or deposits that may be fouling them and clean or replace them as necessary.
Re: Primaries fueling unevenly, hard starting, surge.
Thanks Apeiron. I will check the needles and the seat to check for debris. Does this require any disassembly of the carb? I have done it once before ten years ago during a rebuild. And also, is my M/C solenoid supposed to be cycling all the time? It is always clicking period, except when I turn on the ignition before cranking, it just cycles for a few moments when I do this and then stops. I read on this forum that it is supposed to stop and start as needed when the engine is running, its always on as far as I can tell. Is this correct?
Moderator
Joined: Jan 2000
Posts: 20,981
Likes: 11
From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: Primaries fueling unevenly, hard starting, surge.
You'll have to take the top of the carb off to check the needle and seat.
The MCS will be clicking all the time while the engine is running.
The MCS will be clicking all the time while the engine is running.
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92camaroJoe
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