Weber with LCE adapter now guzzling gas but running fine
 

I got an 86 pickup with a weber and that horrible adapter with a vacuum leak. I finally got around to the LCE adapter. But then I noticed the gas gauge dropping. I did just replace the sending unit and then the gauge when that din't work, and so the gauge read 3/4 tank when full. But after getting a full tank, it was already down to half a tank by the next day. I drove to dinner and took a little drive and it had gone down another 1/8". I have a small exhaust leak and the exhaust in the cab smells a little rich. When I tune the idle mixture, I usually go back and smell that too, but it wasn't too bad. I would have liked to get that leaner than seemed possible at the time, though. It's not displaying any major running problems, but it seems to have less power than that first test drive I took.

I did have the carb upside down and sprayed it with carb cleaner to clean the outside of it some more. I did check the float bowl this morning, and it was not too full and moved freely. I am ordering a repair kit, but I was also wondering if anyone else installed the LCe adapter and had clearance issues with any downward facing small jets in the base of the carb, there were not any cutouts beyond the two main bores in the teflon base gasket provided, so I installed it trustingly. If there are any tests beyond checking the accelerator pump diaphragm for holes, I would appreciate some expert Weber input here, as this is my first 22r with one. I was anticipating having it perfectly dialed in and the improvements it would bring, but they were short-lived.

My weber 32/36 DGVE carb repair kit comes in Friday, so I'll have all weekend to rebuild the carburetor and then tinker from there if needed to get rid of the fuel overconsumption gremlin so I can get back to my electrical gremlins....

To get the best performance and MPG out of a 32/36 it has to be tuned to the vehicle and conditions.
One condition is location / elevation. Your location is not showing on your profile.

You didn't mention a pressure regulator or what psi it is set at.

A picture of your plugs after a clean cut-off run would be useful.

The simplest test of the accel diaphragm is to see if there is a squirt of fuel when you actuate the throttle.

No, I mean either the fuel gauge is messing up and diving, or it's dumping fuel and getting 5-10 mpg. It's a major malfunction. It happened since installing the LCE adapter. I had the carb upside down and sprayed it with carb cleaner on the outside. This isn't a new Weber installation, why isn't it running fine upon installation thread. It had a vacuum leak and still got decent fuel economy before the new adapter.

So if there is a problem with the accel diaphragm, I would have bad idle and the squirt of fuel would be continuous? And is this the same as the power valve?

As far as the idle circuit goes, now with the vacuum leak sealed up it idles fine at 2-3 turns out. Maybe a little outside the range of that jet, but acceptable. Maybe for the tuning I should be looking at a different beginner's guide to Webers, but I'm looking for big, glaring problems and tests for them. For instance, I was doing a little reading this morning and someone was talking about a power valve test. I couldn't quite visualize it from the words that were written, so I thought I'd ask in a thread of my own. I will have the gasket kit in case I need something from it this weekend.

I don't have a pressure regulator yet. This recent major dive in fuel economy, emptying half a tank in a day, was not happening before I installed the new adapter that doesn't leak. That's what led me to question the base gasket I'm now using and to want to know the anatomy of those two small holes, or maybe it's one in this model, that appears to connect to the acelleration pump area if I remember correctly.

Without a pressure reg pump will push fuel past the needle/seat. What fuel pump are you running?

On the acc pump you will see a squirt when you look down the throat of the carb. A one hole acc jet is all you "should" have but there are 2 hole acc jets.

Yeah, when I was still hoping to get the crap adapter to seal up, I did cutouts for both of those accel jets, and then noticed that the casting for the 2nd one is just unused. Now with the old gasket, I forget if there was material cut away there, but with the teflon LCE one, I saw no extra cutout, but trusted that this base gasket would work fine. After all, if this is THE adapter to end all weber adapters, and nobody seemed to be complaining about it out there, why should I question it?

What kind of adapter are you using with yours? And your fuel pressure reg? I have a like-stock fuel pump, but the PO said "this is aftermarket", whatever that means. All signs of his lazy mechanics remove any trust in his statements.

I have been slowly researching weber carbs on 22rs, and have heard of blocking off the fuel return line (to the tank). While it seems like it would be harder on the pump's diaphragm, I hear it decreases wasted volume. My pump is stock mechanical. Are people using electric inline pumps? I really don't want to switch to anything in-tank. And I don't want to change too many variables before I figure out this problem, but I may have to. The gasket material near the bowl of the carb did seem saturated with fuel (while it was still running fine, if a bit rich at idle) and the outside had a fuel varnish stain. I'll pick up a pressure regulator at the specialty import auto supplier when I get my weber repair kit on friday if they have one. I can wait to drive it until one comes in the mail too if I have to order one online. I hear Holley makes a great one.

The acc jet kinda hangs out over the throat so I'm not recalling a cut out in the gasket. No Weber on my current truck - I raced with the 32/36 for a lot of years and learned from a guy who did dyno tuning.

The saturated fuel outside the carb is/can be 2 things - fuel pressure being too high (no reg) and old gaskets (went dry them got soaked). The stock type pump is good I wouldn't change it.

So the truck was desmogged too - is all the smog stuff gone? The charcoal canister is a good thing recycles unused fumes/fuel I would make it work.

Smart on the variables but the carb sounds like it needs a rebuild and reg which would establish your baseline. - PICS would help.

It was likely running OK because the added air (vac leak) was leaning out the rich mix (no reg).

Ok, now we're getting somewhere. I did see the bottom of the carburetor in a video and the jet surface is recessed slightly and there is a cutaway in the material bridging the airspace for it over to the large bore.

I'm looking for something that would cause continuous fuel stream into the engine without much change in performance. For a while I suspected someone siphoned gas from my tank overnight, but vaguely recalled the tank only being just below the 3/4 mark (which again was full the day before, and the gauge displays 3/4 when full) to going to just under the 3/4 mark just before my morning commute- a whole 1/4 tank gone in one day- and then to below half a tank the next day. I doubted that the pump would even pass such a volume going left running into a bucket even with all the RPM changes it went through in a commute. And i now doubt that a fuel regulator would make a big enough difference to stop this level of consumption, but I know it will only help overall, and would set a good baseline. Would you also recommend blocking the tank return line to improve volume passing?

Also, I did go get a set of charcoal canisters and hook them back up. I had a temporary plastic hosebarb, but part of my rebuild will include the threading of that bowl vent and installation of a brass hosebarb with yellow fuel safe PTFE tape. I agree, the canisters are good, and filter the flammable fuel vapors if nothing else. Yes, all the EGR system has been removed, the charcoal canister's "purge" line solenoid or whatever remains intact and I even saved and reconnected the hoses for that from my junkyard charcoal canister set. The bottom of the forward canister that's connected to the carb vents through a grommet into the truck's frame, and the other canister connected to the fuel tank vent has a bottom hose that just hangs- it doesn't have a frame connection or a tee fitting into the frame vent. I haven't figured out where that's really supposed to go. Both have a purge tube vac line that tees together out the tops, and to that solenoid, and from there, I don't know where to. Perhaps a small amount of evaporated fuel is supposed to condense and recycle, but the rest goes out the bottom. I hate having to smell fumes on hot days and it looks like a hack delete job on most of the emissions stuff. I'm cleaning it up every chance I get as usual.

You did get the correct sending unit for the gauge and tank you have??

The acc jet isn't at the bottom of the carb see pic attached. On 2nd pic the circled #1 is the acc pump.https://cimg9.ibsrv.net/gimg/www.yot...ef2d69c25a.jpg

Acc jet
https://cimg7.ibsrv.net/gimg/www.yot...21575e674e.jpg

Acc pump



Please post picture of what you have. - engine bay, - closer pics of the carb etc.

I got the rebuild kit for my carb and I am delighted that it came with an extra gasket for the top to bottom half joint.

I also got a Holley FPR, a model 804. I can't afford to buy a gauge right now, so if anyone else has one and can tell me if there is a good way to set the pressure to the recommended pressure without one, I'd be glad to not have to buy a gauge. Otherwise I will install it and adjust based on how it runs. If it struggles, I'll turn the screw one way until it improves, if not, I'll turn the screw until it struggles and back again to feel out the sweet spot. Just having it in there should protect the float system components against over filling and false enrichment.
EDIT: It took me a minute to find this: "All Holley regulators are pre-set at the factory at 2.8 PSI so there is no guesswork when first installing the regulator."
"Loosening the regulator locknut and turning the adjustment screw clockwise increases the pressure. Decrease pressure by turning the adjustment screw counter-clockwise."
I'll be really careful but will leave it alone for now until I have another problem and then will only fine tune with even more knowledge or a gauge later.

I'll report back in a few hours when I've rebuilt the carb and installed everything. I only get one shot at this until payday next friday, I can only fill the tank back up once, and if it's sucking gas again like it was, it's back to the motorcycle, and drawing board.

You can usually borrow tools, a fuel pressure gauge/ vacuum gauge in this case, from a local auto parts store. Then all you need is a fitting for the gauge port. 2.8 is OK but on the high side I've never set a 32/36 higher than 2.5 even on a race car.

Thanks. I could temporarily tee it in to the rubber line while I adjust the pressure. For now, everything is cleaned, rebuilt, and bolted back together with the regulator set to it's default, the idle mixture at 2 turns out. The idle exhaust smelled the leanest and cleanest since I've owned the truck, so that is a good sign. I'll get into finer tuning tomorrow. I also plumbed a good vent line and played with some brass fittings and a 1/4" NPT tap this afternoon to get it plumbed up and looking nice, that was satisfying.

I'm thinking I might have had the choke spring set too tight before and it was basically running with it on. It's just a theory, but when I pulled off the choke assembly, it was under considerable tension. I looked up how to set the spring tension just right and think I got it correct. I'd been messing with it without knowing quite what I was doing, and with the carb off the engine, I was much better able to see what was going on. I'll be testing the fuel economy tonight soon and will report my findings here.

I'm planning on setting the regulator with a gauge soon, but I turned it about 1/4 turn counter-clockwise to reduce pressure just a bit lower than the factory preset 2.8 lbs. Many people are saying under 3 is good, but there are a lot of yahoos out there too. So I'm going with the advice of people who sound a little more careful and aiming for 2 psi.

I don't think it's guzzling gas, and in fact my initial reaction when I saw how low the gauge went in just a day could have been true, maybe someone did siphon a few gallons. It wouldn't be out of the question around here.

Also noting that the jets have been removed at some point, so the jetting may have been messed with. I may be jetted too rich, and without a vacuum leak to lean it out, am now consuming noticeably more fuel. I am at 50 feet elevation, and am looking for the right jet kit in the desirable range. I'm still looking to put together a chart of where what jets are located so I know what I'm changing, and put together a correct combination so I know how to reestablish a baseline jetting and what to move to after a few tests.

Before we can talk about jetting we need to know what is in there to start with. Also fill in your location then tell us at what altitudes you normally drive at.

it's doing a lot better now. I'm at 50' in Portland, OR and see up to 500' in town semi regularly. One of the idle jets is a 60, I wrote down. I now realize the ball in the accel pump's nozzle may have gotten temporarily stuck up while I inverted it installing the new adapter, or someone siphoned gas, or I overtightened the choke spring. So the major consumption issue seems to have stopped after a couple longer distance drives. I'll have to reinvestigate jetting when I go to re-bush the throttle butterfly shafts with needle bearings a little later on. I just wanted to make sure I didn't have a damaged idle adjustment needle seat, and it's now idling pleasantly lean enough that I'm not as worried about that as I was. I'm also going to get a stock exhaust system before I decide to rejet, this one is another one of those dumb 4x larger than it needs to be fit for a 350ci engine systems. I dobn't know what is with people doing that to these trucks. I know back pressure plays into the mixture as well, which is my reason for waiting.