I have bought lots of stuff including my carbs from Gabrielle aka Alfa1750 on eBay aka Carburetori Italia. Good people.
Weber 32/36's - can't figure it out!
- Thread starter dang
- Start date
Nice discussion folks! Please keep it up!
Okay, I'm back to dealing with carbs after messing with an electric fan addition. BTW, the car still goes past 12:00 a bit while sitting, then the electric fan kicks in and it cools right down. My 5-blade fan on the motor has to go. Later though...
I've driven the car a couple times for short stints and it's running really rough. Even a pop here and there just rolling through a parking lot. I have new power values installed, not sure about the smell of the exhaust, I'll keep checking since it's not obvious that it's different yet, but cruising (steady speed) at any rpm causes the motor to run very rough. Now it seems like it's lean or has an ignition problem. It's a little bit like what happens with a vacuum leak but it runs really rough, not just surging.
I'll start over with the idle adjustment screws and see where I'm at after changing the power valves, but other than that I'm a little lost.
New points, changing the timing doesn't effect the rough running at all, swapped the capacitor, new plugs and wires. I have another distributor but can't remember if I tried it or not. I've taken everything apart too many times. Bah!
I've driven the car a couple times for short stints and it's running really rough. Even a pop here and there just rolling through a parking lot. I have new power values installed, not sure about the smell of the exhaust, I'll keep checking since it's not obvious that it's different yet, but cruising (steady speed) at any rpm causes the motor to run very rough. Now it seems like it's lean or has an ignition problem. It's a little bit like what happens with a vacuum leak but it runs really rough, not just surging.
I'll start over with the idle adjustment screws and see where I'm at after changing the power valves, but other than that I'm a little lost.
New points, changing the timing doesn't effect the rough running at all, swapped the capacitor, new plugs and wires. I have another distributor but can't remember if I tried it or not. I've taken everything apart too many times. Bah!
Is timing all over the place? Wondering if you have a worn out distributor. Had that happened on my 2002.
How are your throttle shaft bushings? tight?
Rough running in all RPM ranges?
How are your throttle shaft bushings? tight?
Rough running in all RPM ranges?
I'll put a timing light on it next to see if it's bouncing. That's what it acts like.
Throttle shafts feel good.
Yes, it runs rough at all rpms. Doesn't even idle all that great.
Did you check the fuel cut off solenoids are working? Granted, that would cause one to adjust the idle screws past it and cause a rich condition... unless they're still not far enough out. Also, did you spray anything (brake cleaner, wd-40) on the throttle shafts?
Cutoffs work good. I've sprayed/cleaned the linkage and shafts. Everything seems to move freely.
Ah. I did a smoke test when I first put them on and didn't see any issues, but I may do it again just to make sure I'm not missing a vacuum leak somewhere else. I haven't tested the solenoids like that but I can. All I know is the engine runs (poorly) and at WOT it has a ton of power, lighting up the tires in second gear. How's that for technical? ;-)
To Ted’s point high on the list of suspects is the slow running and progression circuit. I always go step by step rather than jump about when hunting down carb issues. In your case
(1) make sure the solenoids are working well. If not eliminate them or get new ones. (Bob, I’m still a little suspicious of your front one. Running more gas thru them may help remove old deposits from their hibernation)
(2) check for and eliminate vacuum leaks
(3) synchronized the carbs (Synchrometer or by listening tube or …)
(4) now you are ready to start turning the idle mixture screws to per the manual.
(5! once idle is good then you can troubleshoot progression circuit issues
(6) then chase Main circuit +accel issues (often interrelated).
and so on
(1) make sure the solenoids are working well. If not eliminate them or get new ones. (Bob, I’m still a little suspicious of your front one. Running more gas thru them may help remove old deposits from their hibernation)
(2) check for and eliminate vacuum leaks
(3) synchronized the carbs (Synchrometer or by listening tube or …)
(4) now you are ready to start turning the idle mixture screws to per the manual.
(5! once idle is good then you can troubleshoot progression circuit issues
(6) then chase Main circuit +accel issues (often interrelated).
and so on
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Fuel cutoffs work. I need to get a synchronizer. My timing might doesn't work with that type wire (it's really old) so I'll need to get one. More to come..
Just because your timing is bouncing around doesn’t necessarily mean the distributor is faulty it more likely means that there is a engine misfire causing it.
I haven't checked it yet, I just wouldn't be surprised if it is. I'll try to get a video of what the motor sounds like.
Honolulu
Well-Known Member
I'm nobody's carb guru, but one thing I learned while driving a friend's 2002 that would stay at any idle I set, although it ran pretty well otherwise....is the following.
Weber carbs have pot metal bodies. Prolly most or all carbs do, but let's keep this local. Nothing wrong with that, until you set a steel throttle plate axle through them, and the steel corrodes slightly, becomes abrasive, and wears a larger hole in the throttle body... instant vacuum leak! The axle wobbles and you'll never get the idle stable. The lower vacuum may cause other humbug as well, so once you've verified your jets are appropriate.
Moral of the story: take off air cleaner, prop the choke fully open, stick in a finger and wiggle the throttle plate while you observe the throttle shaft on the outside of the carb (both sides). If there's movement (bet there is), you may have found one of the culprits. The good/bad news is that there are places (I've read on this list) that will take your leaky carbs, bore and stall bushings for those throttle axles, which will at least cure the vacuum leak(s) there. Might be Ireland Engineering to do the work, but surely there are others. No affiliation, although my daughter knew Ace Andrew a long time ago, and he set me up inexpensively with some e30 stuff long ago. He may still be on this list, hellooooo?
Maybe there was a reason whosit sold you those carbs. Was he running them or just rip them from a wreck?
Weber carbs have pot metal bodies. Prolly most or all carbs do, but let's keep this local. Nothing wrong with that, until you set a steel throttle plate axle through them, and the steel corrodes slightly, becomes abrasive, and wears a larger hole in the throttle body... instant vacuum leak! The axle wobbles and you'll never get the idle stable. The lower vacuum may cause other humbug as well, so once you've verified your jets are appropriate.
Moral of the story: take off air cleaner, prop the choke fully open, stick in a finger and wiggle the throttle plate while you observe the throttle shaft on the outside of the carb (both sides). If there's movement (bet there is), you may have found one of the culprits. The good/bad news is that there are places (I've read on this list) that will take your leaky carbs, bore and stall bushings for those throttle axles, which will at least cure the vacuum leak(s) there. Might be Ireland Engineering to do the work, but surely there are others. No affiliation, although my daughter knew Ace Andrew a long time ago, and he set me up inexpensively with some e30 stuff long ago. He may still be on this list, hellooooo?
Maybe there was a reason whosit sold you those carbs. Was he running them or just rip them from a wreck?
Eliminated a few possibilities... Swapped the distributor and it runs exactly the same. Did another smoke test and also sprayed carb cleaner on the throttle shafts at different rpms and no change. I got it to idle fairly decent, but anything other than an idle runs really rough, some slight popping and surging while driving.
I'll pull the plugs and see if they give any clues...
I'll pull the plugs and see if they give any clues...
Pulled the plugs. 4 and 5 looked slightly lighter/hotter but they all looked pretty good in my opinion.
Is it easier to stall the engine by choking out one carb versus the other? I’m picturing putting a balled-up rag over one at a time to see which one reacts more to the missing air supply. Precisely what would be learned is a big ::shrug:: but this could tell you whether air can find a way in somewhere else, etc.
After doing two smoke tests and finding nothing, I'm pretty confident that there aren't any vacuum leaks.
Right, certainly. I think maybe a better way to have phrased it would be to see which three cylinders are missed more. My old Taurus has a program you can access in its ancient computer where it cuts fuel to one cylinder at a time and measures the decrease in RPM as a way to hunt down a cylinder that's underperforming. It's fun to hook LEDs up to the fuel injectors and watch it do its assessment. Pulling the spark plug wires individually would be a similar thing, although I hate getting jolted by doing that.
Looking at your photo again on a larger screen it sure seems like not a whole lot of fuel is going to the 4 5 6 bank. What do you think?
Looking at your photo again on a larger screen it sure seems like not a whole lot of fuel is going to the 4 5 6 bank. What do you think?
I think your plugs are telling you something
If the drop in rpm when you pull a front-3 plug wire is greater than when you pull a back-3 plug wire, then back carb is contributing less to the engine idle than the front.2 reasons are the back carb is flowing less air (not synchronized) or is running too lean (cleaner plugs).
But I still do not think you are gpong about this logically with a basic approach espoused in any manual..
You have already confirmed you don’t have a vacuum leak at idle by spraying the carb bases and checking for missing hoses/caps. Next you should really confirm what you have for jetting, and compare to what comes in an off the shelf 32/36 conversion kit, which you can get by calling Pierce manifolds.
if you don’t have an AFM, the. I would change everything to match what Pierce tells you, synch the carbs, adjust per the book, and test drive
If the drop in rpm when you pull a front-3 plug wire is greater than when you pull a back-3 plug wire, then back carb is contributing less to the engine idle than the front.2 reasons are the back carb is flowing less air (not synchronized) or is running too lean (cleaner plugs).
But I still do not think you are gpong about this logically with a basic approach espoused in any manual..
You have already confirmed you don’t have a vacuum leak at idle by spraying the carb bases and checking for missing hoses/caps. Next you should really confirm what you have for jetting, and compare to what comes in an off the shelf 32/36 conversion kit, which you can get by calling Pierce manifolds.
if you don’t have an AFM, the. I would change everything to match what Pierce tells you, synch the carbs, adjust per the book, and test drive