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Old 04-13-2022, 06:32 PM   #1
68C101775
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Bogging/dying after being revved

Hey everyone,

In the process of attempting to get my 68c10 road worthy. 6 cylinder 250/Rochester monojet. Truck will rev up great but coming off the idle will drop super low and sometimes come back up or sometimes stall and die. I made another post about bogging and dying when braking as well not sure if they’re related. Any tips would be great I attached a pic of her.
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Old 04-13-2022, 07:04 PM   #2
geezer#99
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Re: Bogging/dying after being revved

Accelerator pump.
Stroke the throttle and look for a solid shot of fuel inside the carb.
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Old 04-13-2022, 07:32 PM   #3
68C101775
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Quote:
Originally Posted by geezer#99 View Post
Accelerator pump.
Stroke the throttle and look for a solid shot of fuel inside the carb.
Wouldn’t that cause issues actually reving up from idle and not coming down from the high rpm?
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Old 04-13-2022, 07:56 PM   #4
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Re: Bogging/dying after being revved

On second thought maybe a vacuum leak.
Carb base gasket maybe.

And another thought!
Have you done anything with the distributor?
Changed points or checked the gap or dwell?
Some distributor problems cause your running problems.

Last edited by geezer#99; 04-13-2022 at 08:22 PM.
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Old 04-13-2022, 08:54 PM   #5
68C101775
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Originally Posted by geezer#99 View Post
On second thought maybe a vacuum leak.
Carb base gasket maybe.

And another thought!
Have you done anything with the distributor?
Changed points or checked the gap or dwell?
Some distributor problems cause your running problems.
I just changed the rotor button, cap, wires and plugs and messed w timing. I haven’t done anything w gap or dwell but I don’t have a dwell meter. I can check the gap w feeler gauges tmrw
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Old 04-14-2022, 07:58 PM   #6
toolboxchev
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Re: Bogging/dying after being revved

Get a couple of things you will use over the course of the next few years,

Compression tester
Leakdown tester
RPM Gauge
Vac gauge
dial back timing light

It will save you tons of time to get the engine diagnosed properly from the start.

Erroneous answers are just pointers to one direction or out of scope of the problem.
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Old 04-15-2022, 09:10 AM   #7
CantPutTheSmokeBack
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Re: Bogging/dying after being revved

Sounds like both my truck and Caprice when I put new carbs on them, before rejetting. They were jetted so rich, when I would give it any throttle it would give way too much fuel and not burn through enough before coming back down. If you can, get a wideband AFR gauge. They're not cheap though. But I'll never have another vehicle with a carb and no AFR. The free version of this is of course reading plugs, but I've had and seen in others issues even when following guides to the letter.

Last edited by CantPutTheSmokeBack; 04-15-2022 at 09:19 AM.
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Old 04-15-2022, 09:42 AM   #8
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Re: Bogging/dying after being revved

Quote:
Originally Posted by CantPutTheSmokeBack View Post
Sounds like both my truck and Caprice when I put new carbs on them, before rejetting. They were jetted so rich, when I would give it any throttle it would give way too much fuel and not burn through enough before coming back down. If you can, get a wideband AFR gauge. They're not cheap though. But I'll never have another vehicle with a carb and no AFR. The free version of this is of course reading plugs, but I've had and seen in others issues even when following guides to the letter.
I’ll look into that. Found a vacuum leak where the intake manifold met the head so I’ve got those pulled off for a new gasket. If that doesn’t solve my inconsistencies I’ll go back to the carb. Got a dwell/tach in the mail on the way so I’m hoping with that, a timing light, and vacuum gauge I can just get her consistently roadworthy while I attempt my first engine build for her.
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