VERY high idle issue after installing the Weber 32/36DGEV

[villegs]

The first day I had the carb on the truck ran and idled great, the next day the truck idled too low and would cut off(500rpmish) I adjusted the idle set screw up to 750rpm and again the truck ran great. Since then the idle has gotten increasingly higher, now at 2000rpm. I've gone round the motor numerous time with carb cleaner to find any leaks, there was a mild leak around the manifold heatsink joint, I tightened those bolts and idled dropped to 1850ish, but has since gone back up to 2000. Other than the high idle the truck runs great but is running rich as it smells caustic and when it sits running, stains the ground with carbon soot. I've set the idle set screw so far back the butterflies stop before the screw does, I've tinkered with the idle mixture adjust screw, screwing it in increases the idle even more, contrary to what the tech sheets from redline say, I've not touched the adjustments otherwise. The only vacuum hoses remaining are to the vacuum advance, and the big hose that runs to the back of the motor. I've got the EGR blockoff plate and the AIR injection check valve capped off as well. The choke seems to operate as it should, being it idles a bit higher at start but drops after a short time. I'm thinking I've gotten a bad carb from Redline/Webercarbsdirect but so far have gotten no answer from their warranty dept. Any other ideas or anyone dealt with them and had better luck than I?

[banzai510(hainz)]

make sure the vacuume advance is from the carb port and not the manifold.

 

try timming the motor w/ a light to say around 10deg BTDC and see where you at and adjust the speed screw and mixture again.

 

make sure the choke is fully open and the cable goes fully back. But sounds like you know what your doing.

 

I dont know what a manifold heatsink joint is but I do know the carb adapters are thin and could crack causen a vacuum leak if over tighten

 

 

i would adjust the mixture screw(brass with tension spring) IN and OUT till it runs the best. then look where my timming is then adjust the speed screw lower

Male sure choke plate is fully open(warm)

[Doctoraudio]

The first day I had the carb on the truck ran and idled great, the next day the truck idled too low and would cut off(500rpmish) I adjusted the idle set screw up to 750rpm and again the truck ran great. Since then the idle has gotten increasingly higher, now at 2000rpm. I've gone round the motor numerous time with carb cleaner to find any leaks, there was a mild leak around the manifold heatsink joint, I tightened those bolts and idled dropped to 1850ish, but has since gone back up to 2000. Other than the high idle the truck runs great but is running rich as it smells caustic and when it sits running, stains the ground with carbon soot. I've set the idle set screw so far back the butterflies stop before the screw does, I've tinkered with the idle mixture adjust screw, screwing it in increases the idle even more, contrary to what the tech sheets from redline say, I've not touched the adjustments otherwise. The only vacuum hoses remaining are to the vacuum advance, and the big hose that runs to the back of the motor. I've got the EGR blockoff plate and the AIR injection check valve capped off as well. The choke seems to operate as it should, being it idles a bit higher at start but drops after a short time. I'm thinking I've gotten a bad carb from Redline/Webercarbsdirect but so far have gotten no answer from their warranty dept. Any other ideas or anyone dealt with them and had better luck than I?

 

Take a pictures it could help someone figure out what is wrong.

I had no power to the fuel shutoff. That caused the car to idle funny from time to time. The guy before me did a bad job of wiring.

[yello620]

Need to verify a few things, i bet money on it that you dont have a faulty carb and the warranty department is going to tell you to go piss up a rope.

 

Are both of the throtle shaft butterflies FULLY closed?

Do you have a fuel cut solenoid on this weber?

What manifold is this weber installed on?

Which style adapter did you use to install it?

What throttle linkage did you install on the carb to adapt to your cable linkage?How tight is the throttle shaft nut? Almost bet money that this is where part of your problem is.

 

 

How did your motor run with the previous carb? Any other changes made when the weber was installed?

 

Time to post some pictures, and dont bother with crappy cell phone pics.

[villegs]

Replaced the factory carb which also ran rich despite feeling like the motor was starving, it idle poorly and bucked while driving. The vacuum advance hose indeed plugs into the feed hose off the base of the carb not the manifold. I used the factory cable bracket. The cable nut at the carb uses an e-clip to hold to the throttle linkage on the carb, it swivels freely, also the cable has slack at idle position. The adapter used was the 2 piece one, all gaskets were siliconed, nuts and studs were blue loctited. The heatsink riser being the plate at which both manifolds join, the plate was beadblasted along with the stock U67 intake manifold before reinstallation, all new gaskets on manifolds and heatriser of course. I did not use the fuel cutoff solenoid, should I?

this is the big hose, I don't know what it does, it connects to a tube that goes the back of the head or block

this is air injection check valve and it cap

cap for little fitting at the brakebooster line

capped ported vacuum switch, so bugs don't get in it

business side of carb at idle, butterflies shut choke open truck warm

[villegs]

If any specific pictures may help please let me know.

[villegs]

I did swap electric fuel pumps, but ran same before and after, the one I replaced was a 5-7psi rotatory vane pump with regulator and dropped it back to a 1-4.5psi solenoid pump with regulator. Regulator is actually set low at 2.5psi, but have tried it a various pressures with no change in idle. Also I recommend any with a rotary vane pump to switch to a solenoid pump, it's so beautifully quiet.

[yello620]

Ok, step one in working on cars(not meant to be a dick in this comment though)

You do NOT need silicone/rtv for ANYTHING on that motor except for the four courners of the timing cover. Use a gasket or use RTV, but you dont need both. Let the gasket do its job.

 

Secondly, Gasoline/fuel dissolves silicone/rtv, so you are guaranteed to have vaccum leaks, might not be showing yet, but they are coming. Almost bet that this is part of your high idle. those siliconed gaskets are now garbage, you couild make a better gasket out of cereal box cardboard.

 

My next question was not full answered about the throttle shaft. You say that the idle screw is adjust so far back that the shaft does not touch it? How close is it to touching? I have a feeling that the electric choke is holding the throttle shaft open a very slight amount.

 

Warm engine up, shut it off but turn key back on to keep choke heater warm. No look down the carb to see if the main butterfly is 100% COMPLETELY closed. And look to verify that the choke linkage is not in contact with the main throttle linkage.

 

Next, can we get a good close up picture of the nut that holds your throttle linkage onto the carb.

[villegs]

I got pissed and pulled the carb after work today. Yes, the secondary butterfly was not shut all the way, the adjust screw that stops it had wiggled forward and high idle commenced.......Adjusted, loctited and idles now at a purring 750rpm :) Again, many thanks for the tech contributions guys, i've been too long in the F.I. camp and forgot a lot of the nitpicky carb fiddlibitz.

[yello620]

Anohter thing to remember when adjusting you Weber is to follow the manufactures guidlines. Lots of people think and want to adjust them like a Holley of Edelbbrock four barrel. Doing that will make things worse, because the Weber process is kinda backwards of everything else.

 

I can adjust a weber without a problem, but give me a holley and i am going to go find my running shoes.

[Doctoraudio]

I did not use the fuel cutoff solenoid, should I?

 

Hell. yeah! I bet that is 50% of you problem.

 

It needs to see 12 volts for it to work right.

[banzai510(hainz)]

the 32/36 DGEV-IC has the selinoid. Not all of them come with it unlrss you spec order the IC carb.

sometime the 2nd barrel might be cracked open also

[villegs]

Ya mine did not come with the solenoid, there's a plug where I could put one, but it didn't seem necessary to me.........but like I said I'm been messing with F.I. for the last 10 years

[yello620]

Ya mine did not come with the solenoid, there's a plug where I could put one,

 

That is not a plug where the solenoid goes, that is the idle jet holder. Unscrew that and you will see your primary idle jet.

Probably has a 50 marked on it. There is a matching one on the opposite side of the carb too, thats for the secondaries.