My Holley 950 hp has been screwing with me now for a week! I got past some problems I had posted earlier about flooding, but I still have one issue, the primary power valve. When I start the car after sitting for a night, it will run OK for about 10 seconds and then start loading up, BAD!! I found out that my float level when it runs seems to be OK on both bowls, ( it is hard to check since it wont run very long), but when I shut it off, the primary bowl level looks good at first, but after a few minutes, the bowl apparently leaks down. If I pull the bowl, there is only fuel left below the power valve level. Secondary bowl is fine. I pulled the PV and tested it, it was bad. I replaced it with a known good one that I tested first, and tried again. Same thing, runs OK for 10 seconds and loads up. Same indications on fuel level. Pulled power valve, it was blown. I didn't have any backfires or spit back thru the carb as I was watching it all the time. My timing was verified as I was able to run it long enough to check.What the heck could blow that valve within seconds? My regulator is set for 7psi and the gauge checks good right before the bowl. I suppose the blown power valve caused the fuel to leak into the intake even after the engine was shut off. This carb was dyno tuned by JW and ran razor sharp for months until these problems showed up. I am running a 6.5 valve up front and none in the rear. Leaking gaskets in the metering block or somewhere? I am perplexed! Any ideas out there? Thanks in advance, Brian o No: o No:
Update........ I had the carb guy at the local speed shop take a look at it this morning. Other than the primary float keeping the fuel level a lttle low, nothing just jumped out and grabbed him. He removed the check ball for the power valve anti-blow setup, and now we will see. My check ball retained by a threaded allen plug, so it is easy to reinstall if need be. He told me that he has seen those get stuck before, causing the power valve to stay open. He also cleaned out all the passages and such with a small tool and air. I will know later this afternoon if that cures it! I am keepng my fingers crossed! Brian :eek2:
I have never had a blown PV cause my fuel bowl to empty.uzzled: I think this is merely a symptom of some other problem. What that is.....I don't know.o No: Nor do I know what could cause you to loose a PV the way you describe. o No: I'm sure the two problems are related somehow. Hopefully, someone more knowledgable will chime in soon.:TU:
probably, Adam. Problem is solved finally! Apparently it was the check valve for power valve blow-out protection that was tripping me up. It turned out that the 2nd power valve was still good, but that check ball being stuck was causing the power valve to remain open at all times, even to the point it would empty the bowl after turning it off. That ball was removed, and it runs as good as it did originally, and has razor sharp throttle response again! The carb guy told me he hates that blow out protection setup and has seen this before. He always removes it on new carbs unless he is told otherwise. His opinion is that if it is backfiring and blowing the power valve, fix the problem, don't try to compensate for it. It does kinda make sense but I am sure that there is more than one different opinion on this subject! Brian :grin: :grin: :3gears:
Absolutley!!! The most ran the engine between oil changes was maybe 5 minutes. That was the first thing I thought of as soon as you told me the oil was contaminated. I've changed oil 5 times since i sent you the filters. And it never left the garage! After seeing the oil that came out with the last filter, I knew I'd better keep an eye on it. Ya can't be too careful!!! I am sure glad it was figured out.... it was puzzling because there were about 4 different things giving me trouble and it was hard to sort it out. History now! Thanks guys! Brian :3gears:
The carb guy also said that it was possible that the check ball got stuck when it did backfire as I was troubleshooting the secondary float trouble that turned out to be a leaking float. So basically while fixing the original problem, it created a new one, but it showed the same symptoms for the most part as the original one! That's the kind of stuff that even a professional can get nightmares from! Which of course can lead to heavy drinking........ Brian :beer :beer :beer P.S. The carb guy is Gary Breyer who owns B&H Speed in Wood River, IL. He has long been a distributor guru and even had an article written on him in Popular Hot Rodding. Feb 1997 issue I believe. It was on performance building and tuning of distributors.
I hope so too! I have too many other things I would like to do to it other than chase trouble! If you knew half of the trouble that motor gave me before JW got ahold of it, you'd die. And even JW had to beat it into submission! I guess after I took it out of the Electra donor car, it must have thought it was retired! It sure didn't want to work! Jim is probably still going through therapy after that got done with him! It did have a mind of it's own....... Brian :shock:
