New 38 DGES Weber, Need Help Adjusting!

[heathzx]

I've installed a 38DGES Weber on my 1985 Accord, 1.8L N/A, Manual 5 speed Trans, and went with 2" pipe from the CAT-back.


It idles nicely, but I get a bad stumble and hesitation on acceleration UNDER LOAD, at about 2000rpms, UNLESS I press the accelerator pedal a little further then it can "hop" over that stumble or flat spot. So typically how I have been getting over this flat spot is just by accelerating faster, so pushing the pedal down further then letting up after I get over 2000rpms. I can rev the car all day and will get no noticeable hesitation or stumble while parked.



Here are my specs and other useful information:

-Ported intake plenum (no middle divider).
-At 0 degree timing I have a smooth 770-790 idle (I don't know the degrees while revving).
-Both mixture screws are adjusted equally outwards (I would like to comment more on this below).
-I have not found any vacuum leaks.
-New fuel pump pushes 2.5psi minimum up to 3.5psi maximum.
-New fuel filters (both of them, at the gas tank and at the engine bay).
-New dizzy cap and rotor
-Fresh gasoline
-Uniquely weird hiccup sound coming from intake area while idling (sounds like a click noise sorta made with your tongue that happens about every second).
-Cannot hear that hiccup sound while revving even a small amount.


I am curious whether or not the mixture screws should be adjusted equally on this car since I read that on this page https://www.3geez.com/forum/carbureto...izes-dcoe.html

I have a hunch that the mixture screws shouldn't be equally turned out and that is why I'm getting that unique click sound from the intake area. I'm thinking it's not getting a proper fuel/air mixture to the cylinder every now and then, every other second or whatever. Maybe this is the cause of the hesitation and stumble...

However maybe I'm bonkers. I really want some help on getting this car to run correctly. Thank you!

[cygnus x-1]

It idles nicely, but I get a bad stumble and hesitation on acceleration UNDER LOAD, at about 2000rpms, UNLESS I press the accelerator pedal a little further then it can "hop" over that stumble or flat spot. So typically how I have been getting over this flat spot is just by accelerating faster, so pushing the pedal down further then letting up after I get over 2000rpms. I can rev the car all day and will get no noticeable hesitation or stumble while parked.

That's mostly likely a jetting issue. You could possibly need a bigger pump jet or main jets, or even idle jets; it depends on what the AFR is though the RPM range. The interaction between the idle jets and main jets can be rather subtle, so it's not always obvious what needs to be changed. I'm pretty rusty at carb tuning now but I had my 38 tuned up quite well when I was still running it.

It takes a bit of cash up front, but if you're up for it; pick up a wideband O2 sensor with data logging capability and take some logs while driving around. Then you can look at what the AFR is doing and see where it needs more or less fuel. Then swap out the jets and try again. Repeat until satisfied.

-At 0 degree timing I have a smooth 770-790 idle (I don't know the degrees while revving).

What is the timing at idle (with vacuum advance connected)? You can likely advance it a few degrees from there and pick up a little extra throttle response.

-Uniquely weird hiccup sound coming from intake area while idling (sounds like a click noise sorta made with your tongue that happens about every second).
-Cannot hear that hiccup sound while revving even a small amount.

Exhaust leaks can make this sort of noise but that's too slow. The only thing that could be that slow is a belt noise, like it's rubbing or scraping every once around. If the belts look ok I wouldn't worry too much about it unless it changes or starts getting louder. Some engines just make funny noises.

I am curious whether or not the mixture screws should be adjusted equally on this car since I read that on this page https://www.3geez.com/forum/carbureto...izes-dcoe.html

I have a hunch that the mixture screws shouldn't be equally turned out and that is why I'm getting that unique click sound from the intake area. I'm thinking it's not getting a proper fuel/air mixture to the cylinder every now and then, every other second or whatever. Maybe this is the cause of the hesitation and stumble...

The idle screws won't be adjusted exactly the same because the air flow through the carb isn't perfectly balanced, but they should be within half a turn or so of each other. Neither screw should be more than 2 turns out. Just adjust them until you get the highest vacuum reading.

The strange sound won't be related to this. The idle screws also have no effect beyond idle.

The idle jets however do affect fueling at low throttle as the main jets start to come in.


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[heathzx]

I'm a bit confused about all of this as you can tell.

However, what I am most confused about is why would this little engine need larger jets? I don't know much at all about carburetors but this essentially stock 1.8l engine with a 38DGES makes me think it doesn't need more fuel delivery. Or maybe I got all of this all wrong. Explain more please.

-Lastly, what does the stock oxygen sensor even control or help with on this 85' Accord? Does it do anything - did it do anything - or can't it do anything because I have a Weber carb on it instead of the OEM?


Thank you.

[heathzx]

I just realized that it is possible I may not have incorrectly routed some of my vacuum lines, such as the distributor advance vacuum. I will take some pictures of my Weber installation and I hope someone who has a 1985 Accord who has done the Weber carburetor can chime in on whether or not I have things correct.

Anyone at all that can compare their good working order Weber on this year Accord with mine?

[cygnus x-1]

However, what I am most confused about is why would this little engine need larger jets? I don't know much at all about carburetors but this essentially stock 1.8l engine with a 38DGES makes me think it doesn't need more fuel delivery. Or maybe I got all of this all wrong. Explain more please.

You didn't say what jets were in it already, so I just kinda guessed based on my experience with that carb. It could be over-fueled as well. That's why I mentioned getting a wideband O2 sensor to see what is really going on.

Is this carb new or used?

-Lastly, what does the stock oxygen sensor even control or help with on this 85' Accord? Does it do anything - did it do anything - or can't it do anything because I have a Weber carb on it instead of the OEM?

Emission controls only. I'm not as familiar with that engine but since you have a Weber carb I'm assuming most if not all of the emissions controls are already missing.

I just realized that it is possible I may not have incorrectly routed some of my vacuum lines, such as the distributor advance vacuum. I will take some pictures of my Weber installation and I hope someone who has a 1985 Accord who has done the Weber carburetor can chime in on whether or not I have things correct.

Vacuum advance is pretty important and will make a big difference in how it runs. For vacuum lines you should need only two: one from any port on the manifold to the distributor vacuum advance diaphragm, and then one from any port on the manifold to the brake booster (don't forget the check valve).

And then if there are any vacuum assisted controls for the heater/AC you need a line to those as well.


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[2oodoor]

You usually can run a few more degrees of base timing with mods like you have. Re-tuning the carb after that would logically cure a stumble, just be careful of preignition. Always start the base idle adjstments at closed throttle like the redline technique states.
Widebands are truely the way to take the guess work out and recommended but they werent always around "back in the day"
I would pull the top off and become familiar with this weber, their so simple and for one thing the float level needs to be checked even on a new carb for reassurence.

[heathzx]

Okay so I got some pictures uploaded now with my setup. I hope they help.

The first picture is of the brake vacuum hose. The second is showing the small vacuum hose running from the vacuum "tree" to my cruise control. The third picture is of the port I have the vacuum line running from my distributor to the back of the Weber carburetor. I am not sure if I should be in the first port on the dizzy or the second, I just read about installing Weber on earlier Accord models and I think they always referenced to installing on the second port. So I went with that.

As for the intake and exhaust manifold re circulation, I capped them off with copper and JB weld.

The last picture is showing the deleted portions of the old carburetor, but I don't know what I should do with them or if they are not affecting anything just laying off to the side.

I am not sure if my choke is properly adjusted but it seems to idle and warm up at about 2000rpms when cold and if I feather the throttle after it has warmed up some it drops to lower RPMS until it finally idles good about 750-800rpm. So I figured it set up right. I just have the electric choke connected to a excess black and yellow wire (always on).

Does everything look good or right? Anything I should take a picture of to better show the setup?

[heathzx]

This is a NEW 38 DGES Weber from REDLINE.

Where can I find a write up or How-To on disassembling the Weber so I can get the jet size written down and check the float level? (These things I have never done before or really know how to do yet, but I'm a quick learned with just a little guidance).


I have been looking at the Wideband O2 sensors and gauges and they are about $350! I like the AutoMeter brand but wow I don't have $350 to throw at this just yet.

[2oodoor]

Its hard to tell, once I zoom in the pic gets grainy so I dont see details. Make sure that spring is pulling the throttle good and closed, should be a pretty strong spring set up there.
I would get that linkage lined up straight as possible so theres no binding Ever!
I am in process as we speak, of tearing mine down for a quick clean up and put it back on the car... Ive been using the 32/36 for a while. I will try to snap some pics of my install aand teardown and post them. There are some here already somewhere.
You probably dont have to tear the thing down now but that is part of having a weber especialy a 38, playing around with it to get the best mpg and power. It helps to know what size components they put in it since youre under 1800 cc correct? 0 deg btc ignition is low considering the exhaust mod now plus a carb.

[heathzx]

Good news! I readjusted the mixture screws and tweaked them till it ran the best, drove around, tweaked a 1/4 turn on the front one, drove around, repeat, and found the best setting I could possibly get right now without getting seriously tooth and nail accurate. The car is running good and I am able to use full travel of the accelerator without any stumbling or hesitation issues (if there is any hesitation, which I think there is a little, it's really small and almost unnoticeable). It has quite a bit more power and is much better.

The exhaust smells slightly rich with gas but at the same time I might be over analyzing it and imagining things.


The only problem I noticed now is this: When I turn a little sharper than normal the carburetor bogs out for a moment and it stumbles but as soon as I straighten back out everything goes back to running good and the acceleration seems really good. I repeated the test numerous times and the bogging issue is now only related to turning sharply. Is this normal to have problems with this carburetor while turning?


What type of degrees should I be looking at for timing - how would you go about figuring that out?


This is the 1.8l engine, and it is 1829cc according to Wiki.



So a little more information about how I went about adjusting the Weber:

I called up some shops and discovered that I should not have adjusted the mixture screws simultaneously (I believe this is why I had the problems I did, because I had no idea I was adjusting incorrectly!). However, the guide on REDLINE does not explicitly say adjust each mixture screw one at a time so how was I supposed to know that? So yes, how stupid but that's what I did.

So I got the engine up to temperature, shut the car off, turned the mixture screws carefully all the way in till they stopped, backed them out 2 turns each, and then started the car again. The car ran pretty good actually at 2 even turns out for each adjustment screw. So then I adjusted the screw closest to the firewall first and found best lean idle (2.5 turns out) and then I did the same with the screw closest to the radiator. It seemed good at 2.25 turns out but after I drove it some it had slight hesitation so I adjusted it again a couple times, and finally went with (2.5 turns out). That seems to be the best I could get without being super tooth and nail about the whole thing by taking driving notes, etc. So I'm currently satisfied with how its operating but am curious about the turns.

[cygnus x-1]

[QUOTE=heathzx;1159785]
The third picture is of the port I have the vacuum line running from my distributor to the back of the Weber carburetor. I am not sure if I should be in the first port on the dizzy or the second, I just read about installing Weber on earlier Accord models and I think they always referenced to installing on the second port. So I went with that.[quote]

I'm pretty sure you don't want to use the port on the back of the carb for distributor advance. Some engines do it this way but not yours. Connect that line directly to manifold vacuum, like one of the ports on the tree where you connected the cruise control.

After you do this, check your timing at idle with the advance connected. It should be in the 18-22 range about.

The last picture is showing the deleted portions of the old carburetor, but I don't know what I should do with them or if they are not affecting anything just laying off to the side.

I would unplug and throw in trash.

I am not sure if my choke is properly adjusted but it seems to idle and warm up at about 2000rpms when cold and if I feather the throttle after it has warmed up some it drops to lower RPMS until it finally idles good about 750-800rpm. So I figured it set up right. I just have the electric choke connected to a excess black and yellow wire (always on).

Sounds right, except maybe there should be a thermoswitch inline with the choke wire? I had a hot water choke so I don't remember exactly where the electric should go. I think most people connected it to the same wire that ran the choke on the stock carb. Roo will probably know this one.

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[heathzx]

I've been a little busy lately.

So I want to fix the accelerator linkage so that it never binds and has good travel. On this page it was recommended to use the old Keihin Carb's linkage on the Weber for the best results (https://www.3geez.com/forum/frequentl...6-34-38-a.html)

However, there wasn't a write up on a how-to for it on that page.

So I'm going to look and try to figure how to best do it but I'm asking here just in case someone can shed some more light on it too. As soon as I get the accelerator cable situated I'll further tune the carburetor and come back with updates.


Other than that, I went to the junkyard and got a door and also some trim pieces just a couple days ago. The door that was on my car was dented up real bad (girlfriend backed right into it) so it was best to just replace it.

I'm also planning on fixing the rusty parts and doing a Satin Black paint job as soon as time and weather permits.

[88Sleeper]

Hey heathzx, I'm in the process of doing a 38DGAS swap as well (I ordered DGES, but w/e, same thing, right?)

I've got my manifold ported (removed the plenum) and so far I've drilled/tapped the second fuel port (for pressure gauge) & tapped the fuel bowl vent for hookup to the charcoal canister.

I started modifying the keihin linkage from the old carb to fit on the weber, but it's tricky since the throttle plate gears are in the way on these models.

The guys who I ordered from pre-installed the throttle linkage adapter from the accord kit, to the carb, and I'm thinking of a solution that utilizes that.

If I get it done tonight I'll post up to the how-to.

I'm thinking I might post up a full step-by-step instr guide fir the 38, if anyone thinks that would be useful?

Ill post up a new thread with a few questions I have for 2oodoor & the canister...

[heathzx]

88Sleeper: So from the sounds of it, you don't have the Keihin linkage setup but rather the adapter linkage that comes with the kit - that is the same way mine came, with that accel linkage adapter already attached.

It's been a few days now, do you have a finished product or setup for utilizing the Keihin linkage? I have put that off right now because I was doing some body work. I just painted the car John Deere Blitz Black. This weekend I'll probably get another look at the accelerator linkage setup and see what I can come up with if you don't have something successful posted by then.

Thanks for the post.

[88Sleeper]

Sorry heath, I forgot to post in here directly, if you look at my thread, I have pics.

Mine turned out perfect, I had help reading it, and even w/the pedal stomped in, I'm 1mm short of a true WOT. This is probably good, since w/vibrations & etc on the road, it probably is open all the way.

Grats on the paint job. I'm interested if you did it yourself or had a shop do it?

I will hopefully have enough $ to blow, & time to do mine next year

[88Sleeper]

Oh, and you are close, I have the adapter linkage mounted, by the ppl who sold me the carb (lyricist good, since its a pain if the gears get out of synch), with the keihin linkage bolted to it, to hold the cable & provide a rotary surface to turn on.

[88Sleeper]

Probably* ...

I should probably add some disclaimer about my S4's spell checker into my sig...

(Almost) EVERY DANG WORD IS AIRWAYS WRONG!!

[88Sleeper]

*chucks phone at wall*

[heathzx]

*chucks phone at wall*

Hey, just saw those pictures with the throttle linkage from the Keihin carb hooked up to the Weber. Can you give a simple write up about it, or get a couple more pictures from different angles?

I did the paint job myself. Came out pretty good.

[88Sleeper]

Sure, I just slid into work, so until I get home.

Never did a wire up, but I'll put enough pics in for it to make sense one way or another :-)

[2oodoor]

removed part from old carb, drilled hole in it so I could attach it with short 1/4 bolt w/ lock nut and chevy valve cover retainer. Slid it on the 38 shaft. This is the only way to truely get full throttle opening from the pedal and at the same time have unbinding return so you get full closed throttle so the idle jets pull exclusively from the transistion holes. Much better performance when they do.

[heathzx]

So I got out there and customized a fit with the hardware I had available. It seems like it fit pretty good now. I did have to use my grinder and grind away excess metal from the Keihin linkage so it would fit with the Weber linkage. I can upload some pics sometime.

I am having a hard time figuring out the electric choke on this thing. I have it hooked up to a 12v source with key "ON". The choke just doesn't seem to be turned the right amount because it fast idles to warm up even when it's warmed up. Then I can blip the throttle and it will go to normal idle. And then when it cools down for only 10 minutes or so after shutting it off, when I turn the car back on it fast idles even though the coolant temp still reads a good 160 degrees fahrenheit. So bottom line, the trouble I am having sometimes is that it's fast idling even when it's warmed up already.

[JSmythe]

So I got out there and customized a fit with the hardware I had available. It seems like it fit pretty good now. I did have to use my grinder and grind away excess metal from the Keihin linkage so it would fit with the Weber linkage. I can upload some pics sometime.

I am having a hard time figuring out the electric choke on this thing. I have it hooked up to a 12v source with key "ON". The choke just doesn't seem to be turned the right amount because it fast idles to warm up even when it's warmed up. Then I can blip the throttle and it will go to normal idle. And then when it cools down for only 10 minutes or so after shutting it off, when I turn the car back on it fast idles even though the coolant temp still reads a good 160 degrees fahrenheit. So bottom line, the trouble I am having sometimes is that it's fast idling even when it's warmed up already.

I'm excited to hear the proper solution.

I can think of 10 ways i was going to solve the problem, but haven't see anywhere how to do it correctly.

[cygnus x-1]

To adjust the choke you have to loosen the 3 choke plate screws and turn the plate (I forget which direction). There are a million videos on youtube for adjusting carb chokes, and most are pretty much the same.

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[heathzx]

I uploaded a couple pictures of the way I fabricated the Keihin linkage to work with the Weber adapter linkage. Warning: it's not pretty. I used hardware that I had readily available and cared only about function. I had some funky ways of getting the spacing correct with various washers and nuts. But now you can get an idea of what you gotta do, you can make yours aesthetically pleasing.

Really, you just gotta make it flush with the Weber adapter and make sure it doesn't hit up against any parts on the Weber nearby the throttle linkage. So that's why with my fabrication I chose I had to grind away some of the awkward metal pieces protruding from the Keihin linkage.

I will take some pics of the finished product on the car when I can. I'm still confused how to adjust the choke, I might just take it to a local shop to have them set it... I've twisted that choke left and right and can't seem to get it right.

To view more pictures of what was going on and more of the 85 Accord, go here: 85 Accord Photos by heathderr | Photobucket