What happens if the FP is to high. I got a rebuilt 17055025 and its flowing fuel out one nozzle. http://www.carburetion.com/Products/RebuildInfo.aspx?Application=72-74 Buick&Type=R4-4MV&Core=50&CU=4-467&Year=17055025. Don't know my FP at this time. Need to get some fitting together. I'll know tomorrow. But I got a 7043251 73 olds IIRC and it don't nozzle leak on the same car..but it needs a rebuild..
My 7042240 QJ will take 8-10 PSI no problem. Nozzle drip is usually because the throttle is open too much. Early QJ are limited to 6 because of weaker float design.
Thanks Larry.. I'll warm her up in a few start with the old carb first, get some numbers on paper on were she is at... timing, RPMs, Vacuum inches.... Then get the new one on and start messing with her again.
Ok motor stats 570 RPMs Vac 3-4. All vac ports plugged.. Vac at 1200 17ish at this point runs great to the ear, didn't check tailpipe. timing 12 at 570RPMs Off to get some more WD40. and FP fittings
If you are only drawing 3"-4" inches of vacuum then you want to turn your idle up to around the factory setting between 650-800 depending on what engine and transmission you have. I'm guessing the 400. You won't be able to run power brakes at that rpm and vacuum and will likely stall the car when you drop it into drive.
I hear Ya John. I think the big problem is I cant get the nozzle leak to stop. I just took it for a put up and down the street. I had to feather the throttle the whole time. FWIW 570-620 is what the old carb idled at and worked. if I brought it up t0 650-800 she would not stop running when I turned the ignition off.
If you are only getting 3-4" of vacuum, that's a pretty big cam and it will need more timing at idle. Most Q Jets will also need some modification to the idle side of the carburetor. The reason for the nozzle drip is that the throttle blades are open too much so the engine will idle. The front half of the QJ is very efficient, doesn't take very much to initiate fuel flow from the primary nozzles. More timing will allow you to close the throttle blades and still idle. Big block carburetors also have fixed idle air bypass which routes extra air around the throttle blades. Small block carburetors won't have this. With a cam that big, you'll need to buy a QJ that is specifically calibrated for your engine. You can't use a QJ meant for a stock application or other make of car.
OOPPPPS Me Bad the came is not that big Old Carb Stats RPMs 550-600 Vac. Idle @ about 12inches timing Idle Lets call in 11 Im Sure something happened in shipping.. At this point Ive removed top of carb checking Float level.. Couple of the screws were on the not so tight side in the primary bay by the nozzle..
Big enough for the QJ to need calibration. Out of the box holley DP will work on virtually any engine. Not so with the QJ. The reason people dislike the QJ is because they think you can just find one, any one, and bolt it on anything. That won't work. They are different. We have 2 guys right here on V8 that can do the calibrating, it's more than jets and rods.
At this point of time I Put a pressure regulator on got the nozzle to stop dripping & Vac up to about 10.. I hope I didn't speak to soon.. Cant or won't try get carb to run right because now I got fuel line leaks.. Tackle those tomorrow.. Get them leaks fixed then tune the Carb.
Ok Im having major problem with these cheap hose clamps. How many of you guys are needing the use a pressure regulator. with a a stock type fuel pump?? Im thinking new fuel pump from NAPA or Advanced auto parts.
Well this is going to be fun.. I looked on rock auto at multiple fuel pumps for BBB Max pressure range from 6.5 - 8
I use an expensive NASCAR type pump made by CV Products. It puts out 8-9 psi and I have no problem at all with my QJ or 4150 type DP carburetor. The stock pump should not be flooding the carburetor. Send it back to Mark and let him look at the float setting and needle/seat.
I poped the top off and checked both Needle&seat looked great.. Float level was fine,,, I lowered the level just a bit. put her back together. put back on motor, Drip slowed down. Vac went up from 3 to about 5. Put a crappy mr gasket PR on... drip stopped vac up to 10 . Mark went over this carb with a fine tooth comb.. It's not its first dance on the motor . I truly believe its the FP be cease when you crack the line that thing streams gas out over the grill. I don't know why the Olds carb don't leak. But that carb is not quite right.. From what I understand their is a pressure regulator built in to the stock pumps and they do fail on rare occasion, usually the pump goes weak or dies first.
Thought about measuring, But Im have no luck with the hose clamps on the FR to get to stop leaking. Napa has a 6.5 lbs. pump for 35$. it will be here later today . rock auto has a 8 lbs pump but thats a week out.
Well I be damed I've been fighting line leaks,, turns out to be the new mr gasket fuel regulator is leaking...
Don't you just hate that when new parts are defective out of the box? Return it and don't buy another one. You should not need a regulator for a stock pump and Q Jet.
Darn it.. failed again. Sent Mark a vid He said Box her up... That is some of the best Customer service Ive had. Thanks Mark.
