Hi Guys, I replaced the stock 8.5 power valves in my holley 94's with modern valves, at a 4.5 rating because I'm running duals (on my 8BA motor). I flattened the radius where it meets the base with file in a lathe. They seemed to seal properly when I threaded them into the bowl. The problem is that the car runs extremly rich at idle, to the point where its dumping black smoke all over the place. Is there something to do to see if the PV's are leaking? or stuck open? If the valve wasnt sealing properly, should I see fuel leaking down past the PV gasket? At the same time, I replaced the main jets with 50's as there was a mixture of all different sizes in the carbs when I got them. Previously the setup ran well but would dump black smoke on acceleration and had no top end. Now the power throughout the rev range is excellent but just running too rich at idle. I tried to adjust out the rich setting via the idle mixture screws but it didint make alot of difference. Danny
Are the carbs set up progressive or in tandem? Are you running the chokes? Did you have any fit problems with the power valves? Flatman
Why didn't you just buy power valves for the old holley's. Vintage speed and others have them. When I had too big power valves in my dual carbs it would idle good but flood and stall when you opened the throttle at all.
Hi Mate, The setup is a non progressive linkage on a Sharp Super manifold. The setup was running well before and appart from the richness at idle, runs even better now. Both carbs are running chokes and I have made sure that they are off. The brass retainer ontop of the carb initially hit the inside of the bowl, but with a carbide bit I carefully enlarged the area and now there is ample clearance. If you very lightly press ontop of the valve is closes with no problem and doesnt contact the bowl at any point in its travel. The other issue with the PVs is that the come with a radius at the bottom, where the bass meets the shaft. I removed this radius with a file in a lath so that the radius would not hit the area that the power valve screws into. Once I fitted the PV with the stock gasket, it seemed to be a perfect fit? Danny
Hi Mate, I live in Australia, so not only is it expensive to ship them in from over seas, most companies wont even bother. I want to use modern valves as I can source them from just about anywhere. Danny
I might start again from scratch and have them noth at 1 1/5 and lean (screw in) them and see if it makes any difference. Danny
I had an issue with a '94 that was flooding and filling the top of the accelerator pump chamber. Don't know why, just swapped off with spare parts until it didn't do it any longer.... Now they just leak out the bases and throttle shafts Good luck Flatman
what i did with mine was to start with the idle screws out so they didnt touch the throttle plate arms,i didnt have the linkage hooked up yet, made sure that both plates where closed,installed my linkage,and just used the back carb,idle screw to set the idle for both carbs,truned both mixture screws 1-1/4 turns out, on both carbs,then used a sync, tool to finsh dialing them in so far so good,might not be the right way, but its working for me...
iam running 42 jets and 4.5 pv...i also have my acceleator pump linkange in the #2 hole.or the middle hole...on both carbs...this is good reading. http://www.35pickup.com/Carburetors.html and this http://www.jalopyjournal.com/forum/showthread.php?t=36751&highlight=flathead+ford+2x2+carb+setup
I have a uniform set of 44's that I can try. Maybe I should attack it like this: 1. check power valve seal/leaks 2. check float level 3. adjust idle settings 4. if above doesnt work, try smaller jets. dan
FWIW I tried #46 jets in both carbs with 4.5 power valves. It was way too lean. It would buck bad at 50 mph. I put the #51 jets back in it. I just got some #49 to try now. This is with an isky max 1 cam.
Did it dump fuel before you changed power valves? If not it was something you did. If it's a new installation check fuel pressure. These 94s don't like over 3psi.
First, see what happens with mix screws all the way in...quick way to see if fuel is coming from elsewhere, which it almost certainly is. Then be sure your idle is low enough that off-idle hole right above idle holes aren't uncovered at idle. My tendency next would be to utterly eliminate or blame the PV setup; there could well be a leak of some sort at a couple of points. It wouldn't be hard to run a tap into the vac hole and pluggit with a setscrew and goo temporarily. If this gets things under control, get your idle happy, tune car and see if jets are happy with a 1/2 throttle max drive, THEN we'll go at the PV's when you know the other circuits are good. You do have the gasket that's barely bigger than the hole I assume. Check machined area of PV with a flat washer to see if any probs from mod. If PV, problem has to be on bottom side, as any problem above would have no effect until maybe 1500 or so since any stray fuel there has to go through main channels to venturis. Idle jets, which actually control off-idle-maybe1500 can be VERY important. Verify correct holes. Study venturi discharge bars very closely--you have two air bleeds (idle and main) at front leg. These have fairly large holes leading to very small holes--if plugged, they cause richness. I have hole sizes noted somewhere.
Bruce, Your a constant source of knowledge and inspiration. Thank you! I'll be attempting all of this tonight and will report back. Danny
After a quick run to the corner store that required two fillups to get there, there was an unfortunate event. The area is still roped off til the store and parking lot have cooled enough for a helicopter to approach and investigate the results of the tuneup.
I am new to the holley 94 club and just gotta say thank you to Bruce Lancaster for his knowledge and passion for these carbs And thank you to all the other people here that just keeps giving. I am putting a 6 carb setup on my 348 Edelbrock intake 94s. Really big help guys. John
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