firefighterjed
SILVER Star
- Thread starter
- #21
No, my problem is a stumble when first accelerating, in each gear. If I’m slow with the throttle it goes smoothly. And once I’m up a few rpms I can mash the trottlw and accelerate nicely.
Tuning Weber 32/36 on a 2F
- Thread starter firefighterjed
- Start date
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It is interesting that you still have the Toyota linkage. I wonder if that is at its best? Usually they run cable linkage which requires an aftermarket accelerator pedal, or an earlier one.
Perhaps the accelerator pump needs servicing. But my ultimate priority would be checking that you are running the right jets. One of the best things about the Webers is that you can really dial them in. The worst thing about Webers is that people don't always dial them in.
Perhaps the accelerator pump needs servicing. But my ultimate priority would be checking that you are running the right jets. One of the best things about the Webers is that you can really dial them in. The worst thing about Webers is that people don't always dial them in.
firefighterjed
SILVER Star
- Thread starter
- #23
Is there a particular jet kit you would recomend?
Well, the big hurdle for most is getting an exhaust sniffer. Jets are basically ordered one at a time, or you buy too many that don't include all that you might need in a kit.
Those adapter plates must be absolutely dead flat - or you're wasting your time. Either have them surface ground at a machine shop on a belt grinder (made specifically to do this along with heads/manifolds) or use a piece of heavy glass and 220 grit. Use much thinner gaskets than what came with the kit, which is what leads to warping and leaks. I prefer 1/16" or less - most cases, 1/32" woven gray material. Any kit that uses bolts or studs - clean them with brake cleaner and use blue thread locker.
Off-idle stumble is either a clogged primary idle jet or that jet is sized too small. Most installs will use a 45 if the engine is in top condition, otherwise some can be as high as a 60. A full cold/hot compression test is necessary to know the baseline condition of the engine - otherwise, you chase your tail trying to tune it. Many times a Weber is installed due to a failed engine, not a failed stock carb. A Weber will not fix a worn out engine - this is why you must check the compression levels of all the cylinders. In some ways the aftermarket carb is a lot more sensitive than the OEM original - keep that in mind.
There are larger nozzles for the accelerator pump - but those are only used in extreme cases with low vacuum aftermarket cams. The only adjustment for the pump is the linkage itself, if that cam that moves the pump arm is worn, that can cause a slight problem. The stumble is more likely the primary idle jet being dirty or the wrong size. When it's right, the throttle should be very responsive and crisp, almost too sensitive in a way....
Sarge
Off-idle stumble is either a clogged primary idle jet or that jet is sized too small. Most installs will use a 45 if the engine is in top condition, otherwise some can be as high as a 60. A full cold/hot compression test is necessary to know the baseline condition of the engine - otherwise, you chase your tail trying to tune it. Many times a Weber is installed due to a failed engine, not a failed stock carb. A Weber will not fix a worn out engine - this is why you must check the compression levels of all the cylinders. In some ways the aftermarket carb is a lot more sensitive than the OEM original - keep that in mind.
There are larger nozzles for the accelerator pump - but those are only used in extreme cases with low vacuum aftermarket cams. The only adjustment for the pump is the linkage itself, if that cam that moves the pump arm is worn, that can cause a slight problem. The stumble is more likely the primary idle jet being dirty or the wrong size. When it's right, the throttle should be very responsive and crisp, almost too sensitive in a way....
Sarge
Because you identified running ported vacuum at idle, it suggests that your primary idle jet, Idle Speed Screw setting, and/or Idle Mix Screw setting are off. But first, get your adapter plate situated. That is the first order of business; I'm going to just assume that you don't need to add a quart of oil to the crankcase every time you fill your gas tank.
firefighterjed
SILVER Star
- Thread starter
- #27
Regasketted the adapter stack between the intake and the carb. 100% sure there’s no vacuum leak now. All bolts were of the appropriate length.
Pulled the carb apart and noted the size of each component. Sizes are as follows:
Primary/secondary
Air corrector 165/160
Main Jet 140/135
Idle Jet 55/50
Single pump jet -50-
Idle mix screw is 1 3/4 turns out from its seat
Idle speed is barely touching with RPM +\- 700
Timing is +10 with advance disconnected.
Vacuum Advance distributor verified as functional.
The motor has been painted and RTV is visible here & there so it’s likely that a PO did some motor work. No clue if his is the stock cam. I will test compression before my next reply. It usually doesn’t smoke or consume much oil, except about every 10th start it burps some blue smoke at startup.
I’ve been driving it a lot so I can really carefully describe the behavior I want to correct. It stumbles on throttle push, and time I try to accelerate unless I press slowly. So, no matter if I am starting from idle or cruising at 2000 rpms, if I press the throttle quickly, the engine falters before it races away. I believe I have a lean condition in that moment.
I have replaced the accelerator pump and it’s check valve and jet, and the power valve, just to be sure.
I believe I have ruled out all the basic parts as a problem and I’m ready to make some changes.
Since I’m idleing fine and have good power except for when it stumbles My first change will be to try a different accelerator pump jet. A double pump 55.
Here’s a pic of the jet kit I bought.
Pulled the carb apart and noted the size of each component. Sizes are as follows:
Primary/secondary
Air corrector 165/160
Main Jet 140/135
Idle Jet 55/50
Single pump jet -50-
Idle mix screw is 1 3/4 turns out from its seat
Idle speed is barely touching with RPM +\- 700
Timing is +10 with advance disconnected.
Vacuum Advance distributor verified as functional.
The motor has been painted and RTV is visible here & there so it’s likely that a PO did some motor work. No clue if his is the stock cam. I will test compression before my next reply. It usually doesn’t smoke or consume much oil, except about every 10th start it burps some blue smoke at startup.
I’ve been driving it a lot so I can really carefully describe the behavior I want to correct. It stumbles on throttle push, and time I try to accelerate unless I press slowly. So, no matter if I am starting from idle or cruising at 2000 rpms, if I press the throttle quickly, the engine falters before it races away. I believe I have a lean condition in that moment.
I have replaced the accelerator pump and it’s check valve and jet, and the power valve, just to be sure.
I believe I have ruled out all the basic parts as a problem and I’m ready to make some changes.
Since I’m idleing fine and have good power except for when it stumbles My first change will be to try a different accelerator pump jet. A double pump 55.
Here’s a pic of the jet kit I bought.
The question is why are you able to idle at 700 rpm with an essentially closed primary throttle plate?
Does the linkage that I'm pointing to below have a fair amount of freedom of movement when you back out the Idle Speed Screw?
With the Idle Speed Screw all the way out, confirm that both throttle plates are closed on the inside middle of the carb, and the outside drivers and passengers side of the throttle bores? Shine a flashlight and look at an angle, obviously, the choke butterfly must be open.
How did you accomplish this on the DGV?
Does the linkage that I'm pointing to below have a fair amount of freedom of movement when you back out the Idle Speed Screw?
With the Idle Speed Screw all the way out, confirm that both throttle plates are closed on the inside middle of the carb, and the outside drivers and passengers side of the throttle bores? Shine a flashlight and look at an angle, obviously, the choke butterfly must be open.
RevISK
SILVER Star
Hey Jed!
I saw some of your other posts about this…
Come back and wrap this up please?!?
The suspense is killing me.
Also, I’m having the same issue.
I saw some of your other posts about this…
Come back and wrap this up please?!?
The suspense is killing me.
Also, I’m having the same issue.
firefighterjed
SILVER Star
- Thread starter
- #30
Happily! But you may not like it.
The solution to all your Weber woes lies in then following steps.
Step 1, give the Weber to a friend who’s running a motor that is right-sized for the 33/36. Mine went to a mini truck running a 22r. It’s the perfect application and he’s very happy with it. The 4.2L 2F is just too big.
Step 2. Acquire an OEM carb. Thank you PJohnson! (Aisin clones likely work well too, if you tear them down and clean them thoroughly.)
Step 3. Order a rebuild kit from cruiser outfitters.
Step 4. Rebuild it yourself following the YouTube tutorial that Pinhead published. That can of carb dip was magic for getting things clean. That and meticulous scrubbing each little part. (Alternative: send it to JimC or Mark for the spa treatment.)
Step 5. Install and do a full tune up per the factory service manual.
Step 6. Enjoy years of trouble free, adjustment free driving in one of the most iconic 4x4s ever
RevISK
SILVER Star
You’re right, I don’t like it
..I’m not married to this carb but it’s what is on there and I want to beat the stumble. Plus, if I’m spending the kind of money to change to OE I might as well just go sniper.
I know many people have made this carb work on these trucks, in fact at altitude this summer (8k - 13k) mine was one of the better running trucks after I upped the air correctors. Other 40’s with 2fs and aisins weren’t able to keep up on inclines so there is something there.
I’ll keep at it and when the aha moment comes, I’ll try to remember to report back here for resolution.
Thanks Jed, both for your service (I assume you’re a firefighter for some strange reason) and for some insight into this issue.
Ian
firefighterjed
SILVER Star
- Thread starter
- #32
You’re right, I don’t like it
I’m not married to this carb but it’s what is on there and I want to beat the stumble. Plus, if I’m spending the kind of money to change to OE I might as well just go sniper.
I know many people have made this carb work on these trucks, in fact at altitude this summer (8k - 13k) mine was one of the better running trucks after I upped the air correctors. Other 40’s with 2fs and aisins weren’t able to keep up on inclines so there is something there.
I’ll keep at it and when the aha moment comes, I’ll try to remember to report back here for resolution.
Thanks Jed, both for your service (I assume you’re a firefighter for some strange reason) and for some insight into this issue.
After I ensured no intake leaks, valve train adjusted, fuel supply system refreshed, ignition updated to DUI HEI, new plugs and wires, compression tested and within spec, intake vacuum tested and in spec, the only thing left was the Weber. Sarge and others were super helpful recommending adjustments but I still had to moderate my accelerator pedal push in order to avoid the stumble.
The OEM has been smooth, reliable, and consistent. OEM isn’t the magic bullet. It’s all the other stuff along with the OEM carb that has provided the reliable consisted performance that I’m currently enjoying.
Sniper installs should be increasing the availability of OEM take offs and thus reducing prices.
The sniper has no appeal to me. I love the analog nature of the manual choke and having to actually know your vehicle and manage it.
I’d appreciate if you updated your experience here as you go along. I’d be stoked to learn if you are able to crack the code and get is just right.
Best of luck!
brian
SILVER Star
Welcome to the Weber take off club.....your membership package should be arriving any day now.
RevISK
SILVER Star
The appeal of the Sniper is that I routinely go from 500' to 10,000' and I want my girl with me. The odd thing is that it runs better at altitude with the jet change.
I read about this issue on an MG forum and as always, the answer is change a jet, go for a spin!
I'll definitely report back here...
Thanks Jed
RevISK
SILVER Star
waiting...
brian
SILVER Star
The shipping department works about as well as the carbs.......
RevISK
SILVER Star
0-60 mpg in 3 to 5 business days
mattressking
10 digits to freedom
Aisans work great at 13k, I would go up Imogene and Black Bear with factory jetting on a desmogged truck.
There's more to it like Jed said but oem carbs will happily go to 13k with a timing bump which sniper won't do, it will only adjust a/f based on air density.
Trick is making sure everything else is in order as well.
RevISK
SILVER Star
I’m sitting pretty in most ways I feel. Pulling a solid 20 on the vacuum last night. 11* advanced. Humming at 700 rpm.
I know Aisins are the bees knees, if anyone has one they want to give me, I’ll pay for shipping. Oh, I need an air cleaner too. Thanks
The Weber is what is on the truck, I didn’t choose it. Until something else happens imma keep messing with it.
RevISK
SILVER Star
Nate,
This what I need?
Thread 'Central PA - used ASIN Carb'
For Sale - Central PA - used ASIN Carb - https://forum.ih8mud.com/threads/central-pa-used-asin-carb.1346073/
