Power valve question
Thread Starter
5th Gear
Joined: Apr 2003
Posts: 5
Likes: 0
From: Roanoke VA
Power valve question
I' ve got a 427/390 (Holley carb) '67 w/43K orginial miles.
It backfires through the carb around 4,000 (unless I ease the throttle up to that level).
Keeps blowing out the power valve.
Timing and dwell are set right.
I have not rebuilt the distributor but I did have the carb professionally rebuilt. Problem exixted prior to that rebuild.
Any ideas?
Thanks,
:banghead:
It backfires through the carb around 4,000 (unless I ease the throttle up to that level).
Keeps blowing out the power valve.
Timing and dwell are set right.
I have not rebuilt the distributor but I did have the carb professionally rebuilt. Problem exixted prior to that rebuild.
Any ideas?
Thanks,
:banghead:
Melting Slicks
Joined: Aug 2000
Posts: 3,077
Likes: 2
From: The Garden Spot of the Garden State
Re: Power valve question (67opentop)
...what is the condition of the plugs?
...what's the carb numbers on the air horn?
...DON'T tell me you're running a double pumper, it's a boat anchor unless you have one bad butt engine
edit...oops, missed the point that the problem existed before the carb rebuild..., agree that you need to check the timing (need to use a vacuum can) and the basics first...what are your timing specs and btw, when did you first notice this problem and what was the occurence associated with?
[Modified by Kid_Again, 7:07 AM 4/17/2003]
...what's the carb numbers on the air horn?
...DON'T tell me you're running a double pumper, it's a boat anchor unless you have one bad butt engine
edit...oops, missed the point that the problem existed before the carb rebuild..., agree that you need to check the timing (need to use a vacuum can) and the basics first...what are your timing specs and btw, when did you first notice this problem and what was the occurence associated with?
[Modified by Kid_Again, 7:07 AM 4/17/2003]
Le Mans Master
Joined: Jan 2002
Posts: 8,913
Likes: 283
Re: Power valve question (Kid_Again)
This sounds like a timing issue. Are you sure the timing is set up right?
I had a High RPM miss that was due to a faulty alternator at high revs. The car would pop, miss and backfire at 5000 RPM like clock work. Alt. rebuilt cured it.
Mark
[Modified by ghostrider20, 3:01 AM 4/17/2003]
I had a High RPM miss that was due to a faulty alternator at high revs. The car would pop, miss and backfire at 5000 RPM like clock work. Alt. rebuilt cured it.
Mark
[Modified by ghostrider20, 3:01 AM 4/17/2003]
