tom1985

Hi all
does anyone have an old float setting table typically included with a rebuild kit (not mine). I have looked all over the internet and cannot find the float setting for this carb I'm using after removing the computer stuff.

This carb is showing a little puddle of gas at the accel pump area and running erratic and very rich. I had it apart yesterday and it was clean as a whistle in needle/seat so I just adjusted the float down again and it ran great for 10 minutes and then it puddled and ran like crud.

Am now thinking the float is still too high, although I measured approx 14/32" from the 3/16 in measuring point I read somewhere, OR POSSIBLY I'm getting tooo much fuel pressure for this carb??

The pump is the stock mechanical from my 85 camaro 305 vin h and I blocked off the rusted out return line, which I just read can create a little more fuel pressure.
the float setting table for this carb would be greatly helpful and any thoughts on my problem would be appreciated. I have alot invested in this carb already, new base plate rebuild cleaning and new rebuild kit and importantly a welded on throttle arm from my old carb, having the proper connections for the cable and 700r4 cable
thanks
tom

NoEmissions84TA

iTrader: (1)

I have an old Olds book that might have that carb listed. I will check tonight.
You could call Cliff's High Performance Quadrajets for the info: http://cliffshighperformance.com/

Regarding your lack of FP return line, you could install a "T" fitting in the inlet line to the FP and connect the FP return to it. The farther back (closer to the tank), the better.
Follow attached diagram:

NoEmissions84TA

iTrader: (1)

I found your carb in a 1974 Motor Auto Repair Manual pg 2-406

Oldsmobile 1973-74
7043250
Float Level - 1/4"
Pump Rod Hole - Inner
Fast Idle - 2 turns
Choke Rod - .230
Vacuum Break - .200
Air Valve Lockout - .035
Choke Unloader - .300
Air Valve Spring Windup - 1/2 turn

NoEmissions84TA

iTrader: (1)

BTW, your stock 85 block mounted FP has a incredibly pathetic GPH fuel flow rating.
It's also 32 years old.
You should replace the FP with a non return style with a better GPH rating if you are
not going to repair the rotted return line. If you did replace the return line, then a
Carter M6626 is the FP you want and can be bought for less than $20.00.

tom1985

Thank you very much no emm-
not what I wanted to hear about level being 1/4 " (but now I know)as I have it down to 7/16 and it still pushes gas past the accel pump which makes it run like crap. On the 1st start up before this happens it idles great. I just bought an inline fuel regulator to reduce my unknown fuel pressure as a few guys say q-jet like low fuel pressure and this could be the persistent problem. So as far as your fp suggestion, I am on low budget and my stock 305 vin H makes about 165hp, so I'm not looking for speed with this car, just some reliability and "comfort" driving, which I don't have with my 65 lemans with 396-375hp and 4.88 gear, runs 12.30's.

Also I looked up a carquest stock fuel pump for this car and the specs said min fuel pressure 7.5 and max 9.0, I'm hoping this is way too high for my old olds q-jet and the regulator MAY fix the problem.
PS- not to be a jerk but, my 1969 unrebuilt 396 with a cam, also runs a stock mechanical pump putting out 6.5 psi on a 50yr old SW gauge anyway-good enough for low 12's at 115mph-don't believe everything your speedshop guy or various mfrs tell you, and I've always believed, if it ain't broke don't fix it, plus I ain't got any money anyway.
thanks again for your research and if anyone can comment on the q-jet fuel pressure problem, I'm listening
tom

NoEmissions84TA

iTrader: (1)

Look at the thumbnail again.
The explanation says that by blocking the return, you have caused your own problem. The pressure control valve in the FP that maintains the correct pressure will not function correctly.
The low-buck cheat solution is to install a "T" in the supply line and run the bypass essentially back into the inlet.

tom1985

Hey no emm
I must admit when i looked at your thumbnail the 1st time I did not read it all carefully. I will consider this if the regulator I paid 25 for (mr gasket) does not help-however, the wordss in your thumbnail do not really say how this affects psi to the carb, but only it is not stable, also do these comments refer to the original "computer controlled carb" which we don't now have, or at least I don't have, correct me if i err.
I read somewhere that blocking the return line may increase the psi a LITTLE, or cause vapor lock, BUT to me a 7.5psi min stated on the stock aftermkt pump indicates much more than enough pressure for an early 70's olds 350 carb, possibly overpowering the needle and not properly regulating the bowl level, I've read, not to mention a mightyless 165 hp stock 305 non computer controlled SB chevy.
I will let you know what happens with the regulator and then go from there, maybe a "T" is in my future, or a "new" carb with tv cable connection in the proper place, probably not a high gph fuel pump
thanks again
tom

tom1985

Hi all
Well I just finished putting on a Mr. gasket in-line fuel regulator, has a push-in and turn dial to give 1-6psi. Reviews on this thing were not good but I checked the screws holding it together and they were tight, it also came with fittings which I used "high Tack on, and kept tightening little by little until fittings were tight. Used fuel injection clamps (much better than newer screw clamps they make these days and miraculously, NO Leaks. Recommend this thing at least as of today, if you need only a 1-6 range.

I set on 4 and carb now idles good with NO fuel coming out of the accel pump area. Have not driven on road yet and still have a problem where it idles about 800-850 at the lowest with main idle adjust screw all the way out, and fast idle screw out and off the cam, also with both idle mix screws out 4 turns, and set timing at 8 degree btc. Idles good but smells rich still, no black smoke when revving like before when it was leaking-SO, I'm hopeful thus was at least part of the problem. I have no clue however why it will not idle lower, which I would prefer with AT. Have had the base plate rebuilt by a professional and am wondering if the linkage is not allowing the primary flaps from closing, and if these linkages are adjustable??
any ideas anyone?
thanks
tom

NoEmissions84TA

iTrader: (1)

Where do you have your vacuum advance connected to, manifold vacuum or ported?

zed-028

with the linkage disconnected from the cable, the idle screw all the way out and held closed is the idle ok?

if its still high you're looking at a vac leak somewhere. get some rubber caps or some pieces of vac hose with a screw blocking them, cap everything off. see if its something simple

tom1985

advance from a summit stock hei is a hybrid, it says gives 6 degree mechanical adv @ 900 rpm, 8-10 @ 1200 and max of 10-11 @1500 and vacuum adv provides 10 degree. Vac line is connected to a small port about 1 inch above base plate and no vac @ idle on it. It also says, "set initial timing advanced two to four degrees from the factory recommended setting". I believe mine is 6 btc from factory.

I was playing with the timing 2 days ago when leaking and I raised it a little to try to get it to run better, before I put on the regulator. After putting the reg on and it idles about 800-850, I set the timing back a little where I think it's about 8, it dropped the idle a tad.

the other problem I have is I cannot see the numbers on the timing tab, (painted over & poor eyesight from old age) However, I did mark where 4 adv was and add'l lines were in marker, but NOT sure if each add'l line is 2 degree or 4, as I recall the tab I think had 0,4,8,12 stamped on it but not sure which line referred to each number, SO,, I should look in my books and see if there is a picture of the tab, but I doubt it. If you have the same one, mine has 4 "points" on it, and is set on the 2nd one in from the pass side, which I am thinking is 8 adv. I did try to go a little lower and the idle went down a little but seemed to run worse too. I will try that again though.

Vacuum was a bouncy 15-16 when leaking gas and now is 22 from the big port on the from of the base, so I don't think it's a vacuum leak and I only have the brake booster and distr plugging into vac now, others are rubber nipples plugged, and the connections look good.

Just now I started it and after 5-10 min, its idling decent at about 750, off the idle screw with cable not holding throttle arm open, but still runs rich after turning in idle mix screws in another turn to 3 out now. This is better than a few days ago but don't like not being able to go lower idle and running rich (smell and some smoke) as it indicates to me something is still wrong. Sorry for the lengthy reply, i get carried away trying to give all info.
thanks
tom

NoEmissions84TA

iTrader: (1)

Rule out the brake vacuum booster by capping that line also. It is one big vacuum diaphragm. And they do develop leaks.

Pictures would be helpful. Others can spot things that you may think are OK, but are not.
Like they say, a picture is worth 1000 words.