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04-22-2017, 04:01 PM | #1 |
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250 bogs down when pedal goes to the floor
I don't go WOT much with my 250 but if I do while I am already moving it bogs down/stumbles. I let off of the pedal and it runs fine. This is the only issue I have with the engine.
Is this a carb (newish Weber 32/36) issue? Or do I need to look at the fuel pump? Thanks! -Jeff |
04-22-2017, 04:42 PM | #2 |
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Re: 250 bogs down when pedal goes to the floor
Fuel pump or timing. Check fuel pump by putting fuel line in a clear quart jar. Should fill it in 20 to 30 seconds of cranking.
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04-22-2017, 11:58 PM | #3 |
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Re: 250 bogs down when pedal goes to the floor
Didn't think about timing. Does this mean I need to back it off a little?
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04-23-2017, 12:05 AM | #4 |
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Re: 250 bogs down when pedal goes to the floor
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04-23-2017, 12:30 AM | #5 |
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Re: 250 bogs down when pedal goes to the floor
Whew! Good thing I asked! *I'm 36 and this is my first vehicle with a carb and I have a LOT to learn.
I will check tomorrow but I believe I set it in the 8-10 range. |
04-23-2017, 12:45 AM | #6 |
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Re: 250 bogs down when pedal goes to the floor
Make sure you check and set it with the vac advance plugged off.
And try 14 degrees too. |
04-23-2017, 01:02 AM | #7 |
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Re: 250 bogs down when pedal goes to the floor
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04-23-2017, 01:04 AM | #8 |
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Re: 250 bogs down when pedal goes to the floor
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04-23-2017, 01:05 AM | #9 |
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Re: 250 bogs down when pedal goes to the floor
You'll experience detonation which you will hear. I successfully ran my 292 at 16 initial for the longest time. The Bogging could also mean it's running to rich. Have you checked the plugs to see if they are black from too much fuel?
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1966 Chevy C10 "Project Two Tone" http://67-72chevytrucks.com/vboard/s...d.php?t=596643 1964 GMC "Crustine" semi-build:http://67-72chevytrucks.com/vboard/s...d.php?t=665056 My youtube channel. Username "Military Chevy": https://www.youtube.com/channel/UC_h...fzpcUXyK_5-uiw |
04-23-2017, 01:09 AM | #10 |
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Re: 250 bogs down when pedal goes to the floor
I just replaced the head with a rebuilt head and put in new plugs. I've put roughly 30 miles on it since the head swap; would there be any evidence of running too rich on the plugs in 30 miles?
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04-23-2017, 11:06 AM | #11 |
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Re: 250 bogs down when pedal goes to the floor
If it's that rich then yes, The guys here that have run webers have said they are a bit of a pain to tune in.
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1966 Chevy C10 "Project Two Tone" http://67-72chevytrucks.com/vboard/s...d.php?t=596643 1964 GMC "Crustine" semi-build:http://67-72chevytrucks.com/vboard/s...d.php?t=665056 My youtube channel. Username "Military Chevy": https://www.youtube.com/channel/UC_h...fzpcUXyK_5-uiw |
04-23-2017, 04:40 PM | #12 |
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Re: 250 bogs down when pedal goes to the floor
Additional things to check.
Carb fuel bowl fuel level, carb accelerator pump and vacuum advance. Fuel pump: When you check the fuel pump remove the line where it connects to the carb and place it in a plastic container. You should get at least one pint of fuel in less than 30 seconds. To check vacuum advance remove the distributor top and observe while you put suction on the end of the advance tube. It should move and hold the vacuum. If you don't have a vacuum pump, use mouth suction. It's not that hard to make it move. Accelerator pump: With a flashlight look inside the carb throat when actuating the throttle lever. You should see fuel squirting into the carb. If you don't the accelerator pump may be bad. Only way to check the carb fuel bowl level is to remove the top of the carb.
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68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive... |
04-23-2017, 05:52 PM | #13 |
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Re: 250 bogs down when pedal goes to the floor
Thanks, Guys. I'll go through all of the above. The timing was at 10 so I moved it to 12. I'll drive it like this for a bit and will adjust as needed.
I think I need to really work on the carb adjustment, too. My 250 goes through gas quite rapidly! I'm estimating 12-14 mpg; maybe that is typical? |
04-23-2017, 08:33 PM | #14 | |
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Re: 250 bogs down when pedal goes to the floor
Quote:
These old trucks were made mostly for farm and ranch work as opposed to today's trucks which have become every day family vehicles. Good gas mileage was not that important back then.
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68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive... |
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04-23-2017, 09:34 PM | #15 |
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Re: 250 bogs down when pedal goes to the floor
Hills and nothing over 50 for my driving, so it sounds like I am in the typical range.
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04-24-2017, 09:10 AM | #16 |
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Re: 250 bogs down when pedal goes to the floor
I'm not familiar with your carburetor but as you mentioned, tweaking it might improve your miles per gallon slightly. Certainly worth trying.
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68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive... |
04-24-2017, 11:06 AM | #17 |
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Re: 250 bogs down when pedal goes to the floor
That sounds about right for a 250 with a 2 barrel. Tuning it more might help though as weber's have been known to increase mileage nicely. I forget which member it is now that did a 32/36 and spent quite some time tuning it....he got 18 mpg outta that 250.
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1966 Chevy C10 "Project Two Tone" http://67-72chevytrucks.com/vboard/s...d.php?t=596643 1964 GMC "Crustine" semi-build:http://67-72chevytrucks.com/vboard/s...d.php?t=665056 My youtube channel. Username "Military Chevy": https://www.youtube.com/channel/UC_h...fzpcUXyK_5-uiw |
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