Almost no power, sputters under load
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Almost no power, sputters under load
Hey all! I'm new at this, so here goes...
I have a '76 F250 with a 360 V8 and 4bbl Holley. While driving it, under some acceleration, it suddenly begins to sputter/sounds like the engine "misses". Also, it seems to loose power during this. A friend with mechanic's experience has helped me to adjust the carb as it seems the most likely culprit (that I know of), and we haven't made much progress. Any help would be appreciated. Thanks!
I have a '76 F250 with a 360 V8 and 4bbl Holley. While driving it, under some acceleration, it suddenly begins to sputter/sounds like the engine "misses". Also, it seems to loose power during this. A friend with mechanic's experience has helped me to adjust the carb as it seems the most likely culprit (that I know of), and we haven't made much progress. Any help would be appreciated. Thanks!
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I will check the ignition and electrical connections again, though it seems to have always had this issue even right after I replaced the wires, cap and rotor a couple years ago and the plugs a few months ago.
Thanks
Thanks
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Burnthelight88,
I don't know how old the carburetor is without looking up the info. It was on the truck when I bought it about 6 years ago. It appears to be a older Holley 4bbl, maybe 500-650cfm. I rebuilt the carb about 3 years ago, so it had a new power valve and accelerator pump. It ran a little better, but did not get rid of these issues. Could it have blown the power valve or accelerator pump when I fired it up after the rebuild when I noticed the symptoms again?
Thanks again
I don't know how old the carburetor is without looking up the info. It was on the truck when I bought it about 6 years ago. It appears to be a older Holley 4bbl, maybe 500-650cfm. I rebuilt the carb about 3 years ago, so it had a new power valve and accelerator pump. It ran a little better, but did not get rid of these issues. Could it have blown the power valve or accelerator pump when I fired it up after the rebuild when I noticed the symptoms again?
Thanks again
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From: Twin Cities
For what it's worth, I had similar symptoms after getting my 300 I6 going again after my intake/carb swap.
The engine ran great at first. After a bit of running it backfired once and ripped the diaphragm on the power valve. The engine would idle and rev in neutral, but as soon as ANY load way put on the engine it would die.
I have an Autolite 2bbl on my truck vs. your Holley, but I believe the principle remains.
The engine ran great at first. After a bit of running it backfired once and ripped the diaphragm on the power valve. The engine would idle and rev in neutral, but as soon as ANY load way put on the engine it would die.
I have an Autolite 2bbl on my truck vs. your Holley, but I believe the principle remains.
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I had the same exact problem after a tune up. Distributor cap had a small crack that I didn't see when I put the new one on
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Yes it did to me. The engine fired and reved up and sounded great in the driveway. Started driving down the street fine under no load because I was driving down hill. When I turned around and gave it some gas it started misfiring and if I got on it harder it acted worse. I ended up replacing the new parts with old parts until the problem went away.
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