Weber 32/36 idles way lean

[gatorbackbob]

Ok carb ran fine the last 2000 Miles no hiccups, fast idle circuit perfect, Smooth until warm up, idles like crap @ less than 500, unless I back the mix screw out 3 1/2 turns, then idle is decent at 850, I should add that when it idles low and rough with the mixture set 2 turns out, it accelerates in gear and drives without a problem, just barely stays running in neutral at idle. 5 speed 89 lx I also notice that a stream of fuel is visible coming from the barrel tube closest to firewall, but the outer barrel has no fuel running through it at all, if I spray carb cleaner into the middle hole of the venturi screw, I can watch it go through that tube into the barrel and idle picks up. Spraying cleaner all around base produces no change, also no change when plugging vacuum advance.

[2ndTimeHondaOwner]

First thing I would try is to use some seafoam (carb cleaner) for a tank or two, may just have some junk in the carb.

[ryan427]

^agreed. What you're describing sounds very much like clogged jets. Replace both fuel filters if you haven't done that in the last 12 months/12k miles. Nothing wrong with Seafoam but if it doesn't do the trick, try Redline SI1. Someone here told me about it and I can testify that it works. Started using it in all of our vehicles. Lastly, I can only run non ethanol fuel in my Accord. Worth a shot but it is 20 cents more per gallon.


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[2oodoor]

I would start by removing both idle jets ( accessable from outside carb) make sure rubber oo ring present on jet retainer, inspect jet holes for burrs or physical damage marks...these are very particular. Clean jets with spray cleaner, jets should have number stamped on them, likely anywhere from 45 to 60. Whatever you have should be useable but not if you're set up is correct, should only wind up with 1-2 turns out max.
I prefer 50-55 primary and 55 secondary unless you live in cold climate then 60 primary.

You should start out adjustments with idle stop screw on linkage just barely touching the stop. If it wont run there then try to get it to at least stay running by tweeking primary mix screw but not further than 2 rounds out. Check base ign timing at this point to get it close to at least 5 dgrees btc or a little more..not exceeding 14 deg. The objective is to get the best idle with the least amount of throtte opening (idle stop tab screw)
You said the fast idle is great, well typically these have a barely noticable fast idle and its done with quick. Make sure choke blade (butterfly) is almost completley open after engine is warmed up.
Seafoam and new filters always a go to suggestion for fuel delivery, so those are good suggestions but it sounds like the set up has issues here. Vaccuum leaks are the most common with these conversions because the adapter plates can warp if not installed just so so. Can you take some pictures of your install, that may help me as well as anyone else having similar issues.
Btw you should not see gas squirting in both barrels with a 32/36 UNLESS you have a dual squirter accel pump jet, which is a cheat after install modification because those belong on 38 Webers lol.

[gatorbackbob]

Okay after 3/4 tank of sea foam, its running better, I was able to turn the mix screw back in a bit but not where it should be yet, idles fairly smooth right now at 1000 but the idle screw is way in, over half, I'm going to run a tank of premium after this, then another can of sea foam, and see where that gets me, idle jets are clean, can't find a single vacuum leak, timing belt was changed 10k ago. The number 1 plug was slightly wet with gas when I checked, so maybe wires? They're blue Ngk, changed almost 2 years ago, cap and rotor 3 months old, I'll keep you posted after a couple tanks, the butterfly plates do open entirely once warm, my car takes a while to warm up, I put a gmb pump on and it barely ever reaches the operating temperature anymore, if that makes sense.

[Oldblueaccord]

Ok carb ran fine the last 2000 Miles no hiccups, fast idle circuit perfect, Smooth until warm up, idles like crap @ less than 500, unless I back the mix screw out 3 1/2 turns, then idle is decent at 850, I should add that when it idles low and rough with the mixture set 2 turns out, it accelerates in gear and drives without a problem, just barely stays running in neutral at idle. 5 speed 89 lx I also notice that a stream of fuel is visible coming from the barrel tube closest to firewall, but the outer barrel has no fuel running through it at all, if I spray carb cleaner into the middle hole of the venturi screw, I can watch it go through that tube into the barrel and idle picks up. Spraying cleaner all around base produces no change, also no change when plugging vacuum advance.

if you see fuel drip at idle your not lean your way rich. Thats how we tune Holleys on Chevy 350's on Saturday night and a belly full of cheap beer.

I'm thinking your idle screw is out to far and your idling on the main circuit of the carb.


With the car off where is the throttle blades if you look down the carb with a flash light? your close if your idle mixture screws respond but there should not be any fuel drip at idle.

Might want to also double check the timing at 850-950 idle and see where you are.

[2ndTimeHondaOwner]

"I put a gmb pump on and it barely ever reaches the operating temperature anymore, if that makes sense" you might put in a new thermostat and see if it help with this, my old one was sticking open and the car never did want to warm up. Plus if it doesn't change anything it's cheap

[ryan427]

For the novice here, what's a gmb pump?


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[Oldblueaccord]

Make of water pump i think.

[gatorbackbob]

GMB was an oe supplier of honda water pumps in the late 80's . BTW I fixed the idle problem, it was the accelerator pump cam below the arm had some gunk build up keeping the primary throttle plate open and creating the vacuum leak symptom

[2oodoor]

Okay after 3/4 tank of sea foam, its running better, I was able to turn the mix screw back in a bit but not where it should be yet, idles fairly smooth right now at 1000 but the idle screw is way in, over half, I'm going to run a tank of premium after this, then another can of sea foam, and see where that gets me, idle jets are clean, can't find a single vacuum leak, timing belt was changed 10k ago. The number 1 plug was slightly wet with gas when I checked, so maybe wires? They're blue Ngk, changed almost 2 years ago, cap and rotor 3 months old, I'll keep you posted after a couple tanks, the butterfly plates do open entirely once warm, my car takes a while to warm up, I put a gmb pump on and it barely ever reaches the operating temperature anymore, if that makes sense.
Come on... take the idle jets out already :)95% chance that is where the issue is, be careful not to scratch or burr the jet surface or orifice....!! you don't have to take anything apart as they are accessible from the outside of the carb. Also think about using an inline fuel filter between the firewall and the carb. Change out the filter out by the LR upper control arm/Filler neck area in the LR wheel well area.

EDIT ooops I didn't see your previous post lol.. yep obstructed throttle opening preventing proper exposure to transistioning holes will cause idle and tuning issues. :D

[2oodoor]

I would try a thermostat replacement of the temp is barely coming up, the coolant line that runs through the intake manifold does help with atomization which will smooth out cold natured driveability and idle issues.
I usually begin set up of carbs by backing off the curb idle (throttle opening) screw so it barely runs the engine and then make mixture and timing adjustments to get the idle rpm where I want it. The less throttle opening at idle the better the car will accelerate and run overall. Sometimes you have to fiddle back and forth between all those settings to get the best idle. Also note that the base ignition timing can be a few degrees higher than spec, just not so high as to get pre ignition or rattling. This gets you better driveabilty all the way around.
Also look out using a bunch of seafoam if you havn't changed the fuel filters because it can loosen up trash to a finer grade of gunk and run it through the system, not good.. also on a carbed vehicle it will dissolve filter media if it has much age to it.