Help! Rebuilt Carbs, Now Engine Car Shudders at 4k RPM Options

['70PVW914]

Hey folks. I just rebuilt the weber IDF 44 carbs on my 914-2.0 because I was experiencing hiccups/stutters in acceleration from idle to about 3k rpm. Also, the car would idle very low, and then die if you did not give it a good amount of revs after starting. I figured my idle jets were clogged, and since the carbs had not EVER been rebuilt, I re-gasketed, and rejetted them.

Just finished that today, put in new fuel line to the carbs, changed the fuel filter, and troubleshot a strange problem where my accelerator cable seemed to wrap its way around the clutch cable and bind. :headbanger

After all of that.....my car is STILL acting very strange; in some ways things are better, and in some, things are worse!

NOW:

The car seems to idle just fine at a very nice 900rpm after adjusting the idle and throttle body.----SWEET!

The accelerator cable seems to stick slightly, also, the ball joint for my accelerator pedal seems to keep popping off of the pivot point (Is there a trick to this, or is the ball joint just shot?!) Seem to have it on there now, but now guarantees! ---LESS SWEET

Still seems to stutter when reving in gear b/w idle and 2.5k rpm...same as before I rejetted and cleaned (IMG:style_emoticons/default/dry.gif)

Shudders and looses power at 4k rpm in every gear...this thing had crazy power after 4k before I messed with anything. (IMG:style_emoticons/default/mad.gif)

When I replaced the float needles and seats that came with the rebuild kit, I noticed the seats were way smaller on the rebuild. I DID NOT adjust the float level....my first culprit for this less than stellar performance. After reading some posts on here, it sounds like the float should be at between 12.5mm and 13mm from the upper face of the carb. Would this solve these problems?

Also, I DID remove the throttle valves for a clean and inspection when rebuilding...I am hoping this is not the root of the problem, as they do not seem as smooth as they once were.

Don't think its the resize in jets, as I just changed idles from .45 to .55, and air corrections from 200 to 190 as per recommendation.

Where should I start here!!!????? I figure I will measure and adjust the float tomorrow, after I remove the carbs again (damnit). But if that doesn't work...what should I be trying?.....Damn weber book didn't get here in time and I am not the most patient.....

[ThePaintedMan]

4K indicates something more towards the top-end of the carb. Is it possible you put your auxiliary venturies in backwards? This is very easy to do.

Yes, the floats absolutely need to be adjusted correctly. But not likely that is what's causing your issue, IMHO. Your settings should be somewhere around 11 mm with the gasket already in place and 32 mm dropped (without any tension).

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.poustusa.com-13527-1384174375.1.gif)


You mentioned that you removed the butterflies, correct? Did you remove the throttle shafts? Also, do you notice any binding, and are the butterflies closing completely on both barrels? You can check this by shining a light down them and looking from the other side to see light (when the carbs are off the car and drained of course).


If we could get a picture of the carbs, that might help with any immediate visual confirmation. We'll get you sorted out.

You mentioned that you're not patient. Sorry, but owning a car with carbs, especially a 914 is going to require plenty of that. Nothing is going to get fixed all-at-once unfortunately. We've got to work through each issue systematically, but in the end you'll have an awesome reward for being patient (IMG:style_emoticons/default/smile.gif)

[wndsnd]

Not an expert on the carbs yet. Mine are brand new so other than rejetting them I haven't messed with much.

I do understand that ball socket popping off. I am going through the same thing right now. I ordered one from the bird at $14.00 plus shipping which seems to be the going rate unless I missed some secret source.

They have a fairly fragile c-cllip inside that snaps them onto the ball. If I could find some at a reasonable price I would have a 1/2 dozen to keep around.

I just found a thread last night by McMark that had a picture of how he mounts his clutch clevis pin. If it goes in the wrong way there is a lip that catches on the throttle ball socket and pops it off.

I know I was getting some of that action. But I am back to work (slowly I will admit) and won't be able to play again till next weekend.

John

[Razorbobsr]

Not an expert on the carbs yet. Mine are brand new so other than rejetting them I haven't messed with much.

I do understand that ball socket popping off. I am going through the same thing right now. I ordered one from the bird at $14.00 plus shipping which seems to be the going rate unless I missed some secret source.

They have a fairly fragile c-cllip inside that snaps them onto the ball. If I could find some at a reasonable price I would have a 1/2 dozen to keep around.

I just found a thread last night by McMark that had a picture of how he mounts his clutch clevis pin. If it goes in the wrong way there is a lip that catches on the throttle ball socket and pops it off.

I know I was getting some of that action. But I am back to work (slowly I will admit) and won't be able to play again till next weekend.

John

Safty wire the acc ball joint. Bob

[rhodyguy]

confirm the throttle plates are installed with the degree number, like 5*, visible from the top and the beveled edges are in the correct orientation.

after re-jetting you got started with going to the pre-install setup procedure, yes?

['70PVW914]

So, in order to sync the carbs, I need to get a synchrometer. When this arrives will be the next time I take out the carbs to address the float level any other problems before reattaching them and properly synching.

In the mean time, I want to figure out what these other problems could be potentially....

[/quote]ThePaintedMan Posted Nov 11 2013, 05:48 AM
You mentioned that you removed the butterflies, correct? Did you remove the throttle shafts? Also, do you notice any binding, and are the butterflies closing completely on both barrels? You can check this by shining a light down them and looking from the other side to see light (when the carbs are off the car and drained of course).\

My friend recomended we not touch the throttle valves, and of course I insisted we take them out and clean them. Did not remove the shaft, but the way the throttle valves went on , they had a lot of play in how they sat on the shaft.

[quote]rhodyguy Posted Nov 11 2013, 06:52 AM
confirm the throttle plates are installed with the degree number, like 5*, visible from the top and the beveled edges are in the correct orientation.

after re-jetting you got started with going to the pre-install setup procedure, yes?


Just for clarification. the numerical stamp on the butterfly valves should be facing into the engine? or upward into the top of the carb? The LAST thing I want to do is score the inside wall of the carbs....BTW, after putting almost 15 hours of work into this project, patience is something that wears thin.... but I will always have patients for this car..... she's my baby.

wndsnd AhA! C-Clip ordered, temp fix safety wire!

Thank you all for your input. Will let you know if I have any more questions.

[stugray]

I am local.
Work in Boulder, Live in Longmont.
If you stopped by I could have a look for anything obvious or throw a snail on it.
I even have a WB AFR, but for it to work you need a "bung" welded in somewhere.

I have a weber carbed 2.0L on premises we can compare to.
I just rebuilt my dual 40 IDF webers as well.

[rhodyguy]

i misspoke with the degree number i guess. at least with this set. to clarify a bit...both edges of the plate have a bevel, with the shallow edges of the bevels being the closest to the venturi when the plates close. wider carb pict shows the opening aspect and carb orientation for the other pictures. the bevel picture is shown with the bottom of the carb pointing upwards. the degree (78*) mark is on the side of the plate with the longer edge of the bevel. all 4 plates must be installed commonly in the correct orientation. time consuming, edit edit edit, and hard to explain in text and be clear. takes about 2 minutes in person.

buy the cb book and get a synchronizer like the one pictured.

[ChrisFoley]

i misspoke with the degree number i guess...

I believe it says 78 Kevin.

[rhodyguy]

edit. too early.

['70PVW914]

I am local.
Work in Boulder, Live in Longmont.
If you stopped by I could have a look for anything obvious or throw a snail on it.
I even have a WB AFR, but for it to work you need a "bung" welded in somewhere.

I have a weber carbed 2.0L on premises we can compare to.
I just rebuilt my dual 40 IDF webers as well.

PM Sent!

['70PVW914]

Ok guys....bad news. I woke up this morning psyched to adjust the float needles on the carbs and synch them, and I discovered that a piece of the plate that holds the pivot needle for the float is broken and is no longer holding the float pivot in place!

I am so frustrated! I am now wondering if these carbs are just clapped out... Does anybody have any suggestions, or any spare IDF 44 scraps? Could I JB Weld or something to just hold the pin in place for now to get the car running? Should I just buy new carbeurators?.....I really cannot afford this right now!

Heres some pics of the one that is broken piece:



Whats the damage here......

['70PVW914]

That was a joke about the jb weld....

[wndsnd]

I hope you found the piece in the bowl...

[brant]

I actually have seen and used in weld in different gas application. There are some products that are better for fuel. There is also a helicopter certified alloy welder in longmont that I have used to weld motorcycle carbs before.

Don't give up!

[brant]

You might even be able to safety wire that

[Dr Evil]

Is that not an integral part of the float? Get a new float, should be available, and do it right (IMG:style_emoticons/default/wink.gif) Way to stick to it and find the/an issue, though.

[euro911]

It's a broken split tab, Mike - but repairable.

Maybe more expensive than having a bung welded into your exhaust (IMG:style_emoticons/default/confused24.gif) ... but I bought e of these 'portable' exhaust clamps for my AFR. You need to install an O2 sensor in it, but you can move it from car to car quickly (IMG:style_emoticons/default/idea.gif)

Innovate Motorsports Exhaust Clamp - P/N: 3728



Available directly from Innovate (Click here)

or Summit Racing (Click here)

I added a long spring to it so it won't fall off while driving (IMG:style_emoticons/default/smile.gif)

[Dr Evil]

I am used to mikuni, bing, etc, where that piece is easily replaced. Looked integral in the pic. So, the float bolts to the tab?

[Dr Evil]

Ya, a new float will have that tab. This is what I am talking about.