Stromberg 2BBL home tuneup tips pls? ’67 Monaco 383

what color are your spark plugs? are they wet or dry?
 
Hi there, thanks for this - I’ve ordered a new set of plugs so will be interesting to see then & I’ll let you know. I managed to find one set here on the uk on eBay to suit & they are Bosch Platinum 4236.
Also await the new carb mounting gasket from Rock Auto this week.

My latest notion that it might be worth tweaking the timing to suit the different fuel delivery of the newly rebuilt carb?
It ran fine before ...
 
Hi there, thanks for this - I’ve ordered a new set of plugs so will be interesting to see then & I’ll let you know. I managed to find one set here on the uk on eBay to suit & they are Bosch Platinum 4236.
Also await the new carb mounting gasket from Rock Auto this week.

My latest notion that it might be worth tweaking the timing to suit the different fuel delivery of the newly rebuilt carb?
It ran fine before ...

I can't be too much help, but logically if it ran better before the carb was rebuilt, odds are overwhelmingly something is wrong with the rebuild or installation.

Don't mess with other things until you're absolutely certain the carburetor isn't the culprit.

Robert
 
Thank you Robert I agree, just totally lost on what he could have done wrong.
.... it sounds ok at idle it’s just when you rev it or pull away it’s gutless even when floored & only firing on about 5 or 6 cylinders
 
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SORTED! All it was was the plugs had got filthy from rich stop starting during carb rebuild. New BOSCH 4236 plugs & that’s it good to go!
Thanks everybody once again
 
In general, not a lot to go wrong with those carbs. Set the idle mixture, starting at 1.5 turns outward on the idle mixture screws, with a hot idle rpm of about 600rpm or so, as I recall.

Make sure the base plate nuts are snugged-down nicely.

As far as the cold starting issues, when the engine is cold, make sure the automatic choke flap closes fully, then is pulled open a bit as the engine starts by the choke pull-off diaphragm. With the engine cold and everything at an ambient air temp of 70 degrees F, the choke flap should just close, easily and gently, if it's got more "pressure" than that, then the choke thermostat in the intake manifold probably needs to be backed-off a notch or two. With age, those thermostatic springe tighten-up, so if you set it to factory specs, or it is still at factory specs, it'll not let the choke open soon enough to not over-choke the engine.

Back when the cars were newer and we still had leaded fuels, it was common to see the light gray coloring at the end of the exhaust pipes. Which indicated a normal carb mixture situation. BUT when the lead left, the pipes would color "black" and fluffy, typically. As my '77 Camaro did when it was new. So, what you might perceive is a too-rich mixture, from the rear pipe coloring, might be completely normal for unleaded gasoline (ethanol'd or not).

A better check might be to look at the spark plugs instead.

But do ensure that the hot base idle timing is correct for the car. That the idle mixture is set to specs. That the spark plugs are gapped correctly and reasonably clean, as to accumulation or deposits on the insulator and ground electrode.

Also look for vacuum leaks, including the vacuum advance can.

You can set the accel pump arm in the long slot for a bit longer accel pump shot, but generally, the center slot will work just as well, from my own experiences in seeking a bit more performance on out '66 Newport 383 2bbl when it was new (and I was in high school).

Do the carb "kit" AFTER you've done everything else to make sure things are adjusted right and such. By observation, unless the innards are really gunked-up, the carb "kit" deal gave us more peace-of-mind that all was well, with little improvement in performance, if any at all, back then.

It will not hurt to spray the carb with a good carb cleaner, in the venture area and on the outside. When we'd get the '66 Newport tuned-up at the local Chrysler dealer, back then, the tech would get a can of solvent and splash it around onto and into the carb. "Solvize" is what they termed it. This would easily wash the accumulated varnish and such off of the carb venturis and clean up the choke flap to make sure it was free to move.

DO also make sure those well plugs in the bottom are tight and do not leak. They plug passages which go to the float bowl, so when they leak, it can get "firey" under there. On some, which use a staked-in ball bearing surrounded by a sealing solder, modern ethanol'd fuels degrade the solder and the balls can fall out. Not good! Just spray everything down to get it clean and watch that area, for good measure.

Just some thoughts,
CBODY67
So I hope you guys don't mind me trying to get some info here. I have a 1966 Chrysler Newport 383 2bbl with a Bendix-Stromberg WWC Carburetor. I just got the car a month ago and the car sputters and occasionally back fires through the carb. I have ordered a rebuild kit. I worked on these cars 40 years ago, but have not touched a carb in 35 years or so. Any advice???
 
Thank you! I replaced the plugs, wires, cap and rotor the day I picked it up and drove it 900 miles home from Wisconsin, but am not crazy about th edesign of the 3 plug wires on the odd-side that run down through the engine gap backside to the PS pump. I feel thats an invitation for jumping the spark. I intend to install wire trees and insure that condition cannot occur. The sputtering through the carb is what I am trying to get to the bottom of. Previous owner indicated that the car was garaged for years and sat while the gas went bad. He pumped it out and got it running, but I am wondering if there is residual gunk affecting the operation of the carb. If I only give it a little gas, its fine, if I floor it or give it excessive gas, it also seems to run well. Its that spot in the middle when it sputters and spits and then occasionally back fires through the carb that is my issue. It smells rich...can smell unburned fuel when idling in the driveway. I have used seafoam gas additive, and also seafoam carb and choke cleaner and while I feel that it improved, there is still sputtering...
 
The car has 64000 original miles. Was driven by an old man and it spent winters and possibly as many as 25 years garaged. The interior is immaculate really. The dash is like new. The carpets are fine and the seats while just slightly faded, otherwise are in near new condition.
 
Here are a couple of pics

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There could well still be some gunk in the gas tank, but I also would suspect that that much driving might have diluted it down to where it's not that significant. BTAIM

Running the spark plug wires the way that Chrysler ran them does not usually lead to any problens, as you mentioned. Just use OEM-quality/style wires and there should be no issues. From what I've seen, as long as the wire insulators and boots are in good condition, the "jumping" issues are greatly minimized. Look at the FSN illustrations and pay attention to where the various wires might cross over each other and such, too. Trying to "make it pretty" with uniform spacing from the distributor to the spark plug might cause cross-firing issues, I suspect.

What might be an issue is that some of the smaller calibration places in the venturi cluster might have some corrosion in them. Which will not come out with a carb cleaner solution, so they will have to be removed mechanically. Not that hard to do with a set of twist drills, if needed. Just because they are open and will flow carb cleaner through them does not mean they are sitll the proper size (as I discovered on a Carter BBD on my '80 Newport 360).

Other than the main jets in the bottom of the float bowl, the other metering calibrations are in the venturi cluster itself. The idle and main system air bleeds on the topside and the "low speed jet" near the bottom of the solid tube on the bottom of the cluster.

Looks like a really nice car!

Enjoy!
CBODY67
 
Its a LOVELY Newport, quite enviable. I like my '66 2 door, for sure, and the 4 door NY'er I had 16 yrs ago was my Mopar Conversion Experience. Check your timing, vacuum advance, points and stuff too. See how it does w the vac advance disconnected. I LOVE those Bendix WWCs. Even when they're old and dirty, they do better than many other, fancier brands. I got an octogenarian carburetor specialist to rebuild one for me a yr or so ago, and its been EXCELLENT since then, though the old one still fed fuel and air to the engine well. The puddle outside the carb had grown dangerous though.

See if the Romper Room tune-up rituals help. I've read that many "carburetor problems" turn out to be ELECTRICAL!
 
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