455 with Edelbrock performer intake and 1411 (750 CFM) 700R4 tranny. Mild cam. I am in Denver at 5280' above sea level Still trying to set my carb up right. The car runs ok but gassy smelling. Called Edelbrock to get a basis to start from for rods and seats at this elevation and was told to start with stage 16. I am at stage 17 on 1411 chart. From there I have tried several rods and jets to go leaner but it causes the idle to climb at stage 18. Running 15Hg of vacuum. have been running Orange spring (5 Hg)/ 1430 jet/ and 7042 rod that works but still pretty strong smelling.
Changed springs to Pink (7Hg)/ same jets 1430/ and put in rods 7047 to go leaner. It runs well but at idle with the car in gear the idle creeps higher and higher until the car starts to do a burn out if I don't shift to neutral but the car idles at 600rpm normally.
This is driving me crazy to the point of getting one of those fuel injected setups but not really wanting to plunk down $1000. Any help or suggestions would be helpful. I know old cars had issues but they didn't smell this bad.
After many trials I found the right combination. I rebuilt the Q-jet 800 CFM that came with the motor but found out that the TV cable didn't seem to work right with my 700R4. Others probably found success making their own setup for linkage but I needed to be sure it would work right so I bit the bullet and just went with Edelbrock. I got the Edelbrock performer intake on Craigslist for $30 and the Edelbrock carb is easy to change springs, rods, and for the most part jets and it doesn't leak gas all over.
My car is anything but for the purist, however, at least I put a Pontiac motor in it cause I bought a Chevy 350 to drop in. I just couldn't bring myself to do that to such an iconic car.
Does it stink at all rpm or is it primarily an idle situation? What about a plug reading, have you run at cruise speed for five or 10 miles and done a plug check? You push in the clutch, or shift to neutral, and shut the engine off, pull over to the side and pull a plug. If it's black with soot at cruise as well as idle you've got too much fuel or too little air in the idle, transition and cruise circuits.
Sounds like the float may be set too high or the needle is letting some gas bleed by the seat. The 1411 has an electric choke I believe, could that be your problem?
I would think being at that altitude you would want stage three lean which would be 1430 main jet,1453 metering rod and 1427 secondary. Just sitting at idle and the engine speed climbs all by itself is a bit strange. Bleeding in fuel from somewhere or the butterflies are opening by themselves? Do you have a good return spring on the throttle?
I did a lot of adjusting on my 1412 To get the fuel air ratio where I wanted it. I left it a bit rich as that gave me more power, but didn't stink like you describe. Mine is 463 CI and it idles at 500 rpm. I do know they are altitude sensitive, going from sea level then over the Rockies to Calgary, my fuel air ratio changed all the way up and all the way down. Ran cleaner at Calgary's 3,532 feet than here on the island.
They are highly and easily adjustable and you should be able to get yours tuned in just make sure there isn't something besides the tune that is causing your problems, such as choke, float level rigging etc.
Number 1 plug was black with some soot before changing rods. With adjustments of the vacuum spring to a Orange (5Hg) the new rods as stated above along with adjusting the idle speed mixture screws it runs really well now. Just ran it over 40 mins doing 70-80 down the highway from a car show and pulled 1st plug and now it is looking much better. I cleaned the plug off with a small wire brush to get a more accurate color the next time I take it out. I might even get a new set of plugs just to start fresh as I drove it running rich for about 850 miles. It would stink when idling or driving down the road with the windows down. I messed with it late last fall and I think I changed out the secondaries to match the primaries. I probably should look into that to see if that is in fact what I did. I believe I have the choke set correctly. I will keep your recommendations in mind if it stills seems rich but I would rather it be a tad rich.
Wade, You can eliminate the possibility of the choke being the problem by setting it wide open first thin in the morning when cold. That will keep it open all day long, If it solves your problem you know what it is, if it doesn't solve the problem at least you've eliminated the choke as the culprit.
My Edelbrock is manual choke and I just wired it open.
Your cruise should just be on the primaries, as long as the secondaries aren't opened with a lead foot, so the secondary metering shouldn't be your problem. Calibrate that after you get the Idle, transition, cruise and pump circuits good.
I'd start over with the idle mixture. First make sure the float is adjusted correctly then set your idle speed, adjust one needle for the highest rpm and vacuum, readjust the idle speed and tune the second needle. Keep adjusting both mixture screws and idle speed screws until you have them set so adjusting the mixtures produces no increase at the desired idle rpm. Then lean out additionally to get a slight rpm drop. That will be your best lean idle condition,
As far as the springs, try a little lighter one. You want the vacuum signal to keep the rods in the lean step until you have a higher load. If the spring is lifting the rods too early you will get a rich condition. I don't remember what strength of spring is for what colour. If that doesn't help or you have power circuit problems you can always change them back.
Just thinking out loud here, hard to help much not being at the car.
Bluebird428, you have been a great help from afar. I changed the springs and that did stop the car from revving up while in drive at a stop. Went with a lighter set so I may mess around and try an even lighter one just to see how it runs. I did notice that it stumbles a tad from a stop light and then takes off so I am working it through. These Edelbrock carbs do allow you to make numerous adjustments without leaking all over the place which seems to be a great bonus. A friend has a 70 GTO with a 455 and Quadrajet and has to get anther gasket set to try and change his jets and rods for fear of leaking when he is done. Maybe he is over cautious, I don't blame him.
It's easy to make the adjustment when one doesn't have to take the carb off and apart. With my QFT 4150 clone, I have to take it off, take the float bowls and metering blocks off to change the idle feed restrictors, emulsion tube restrictors, power valve channel restrictors, main jets or power valve. At least the idle air bleeds, high speed air bleeds and accelerator system can be done externally. I bought a set of five top cover gaskets for the Edelbrock, part #1499, when I was tuning it but only had to use one.
Is the stumble from stop light with a normal acceleration, when you stomp on it or both? Changing to an even lighter spring may make it worse, but try it and see. It may be the pump system or you could leave the lighter spring you have in it now and try a one size larger jet. If it stops the stumble great if not go back to what you have now and we'll have to try another approach.
Wade, How are you making out with the 1411? I hope you haven't given up on it. I just spent five days trying to tune a QFT Q-850. I've had the carb off and apart a dozen times, changed out 14 restrictors, changed air bleeds 8 times and main jets five times. Just can't get it to idle smooth and quit surging at cruise. Yesterday, after it started on fire, I got so P.O. I yanked the multi $$$$ carb off and installed my old Edelbrock 800 EPS carburetor. Immediate smooth idle and no surge. Once you get the Edelbrock tuned in it will work out well for you.
Bluebird428, I am still tinkering to get it nailed down as I haven't had it out in a couple weeks, though it runs WAAAYYY better than it has for the last year. There is only a hint of the gassy smell so I just ordered the 1453 metering rod and 1427 secondary you suggested and they should be in tomorrow around noon. I thought I would give them a try as I want it to be right, not almost right! You have been a great help and I really appreciate it! Sad you went through the issue with the Q-850 but at least you knew the solution was within reach. I am sure you have a reason for trying to go that route but I would stick with what works.
I was going to try racing it this year, a few races without heading to the mainland. At WOT my 800 EPS had 1.5 inches of vacuum, I replaced the camshaft this year and it will make power at a higher rpm than the previous camshaft so I bought the bigger carb for more air. I maxed out on power at 5200 with the old cam, this one gains HP until about 6200. I have taken the Q-850 completely apart and found some debris inside, I will try it again when I can get a chance. Car is stuck in it's bird house until I get my current work contract done. No work - no eat, what's worse no work - no gas.
