Holley Carb troubles (aka, why I am glad my DD is EFI)

[runawayabc123]

Well, I wanted to rebuilt a carb for practice/fun of it/silly reason here. (Holley 4brl, List1850, aka 4160/4150 series) Single pumper with vac sec. It is on a 289, likely a C code engine, but otherwise unknown with a manual 4speed.

So, after finally getting a kit, we rip the thing apart (way too many "extra" hands doing this too fast) and find we need more parts. Ok, get extra parts. Next, clean up of parts. Do some dipping/parts cleaner, do some boiling. (Two weekends shot by now)

Get things back together (sigh of relief, no "extra" old parts)... some groups rebuilt many times... order of puting things back together really matters. And THANK GOT I TOOK LOTS OF PICTURES BEFORE HAND.

The problems:
The throttle seems a little sticky (aka, the round discs don't move as freely as they did before hand... over boiled, burs, I don't know?) Seems tolerable... but would be nice if fixed. It is sticky on opening from fully closed, otherwise fine.

First try back on the engine... and it flooded it. Literally. Gas everywhere. Gas came pouring out of the vac-sec float bowl over flow/vent tube (my dad thought it was the float and bended the snot out of it and than said it was a gasket leak, I didn't agree with either). (Start arguing with my dad on the problem.)

Adjusted the needle/point set screw super high (aka screwed low... wide open). I think it was almost totally closed before. Tossed back on and tried again. Flooded everything on both the primary and sec sides. Gas everywhere. (Continue arguing with my dad on the problem and that it isn't a gasket leak on both sides now.)

It wanted to start, both times (and did for half a heart beat on the second try before gas guizers flooded everything).

I am thinking the idle set screws are wrong (they are really far out). Or, something is really plugged up somewhere. My dad still thinks it is a gasket leak, but he hasn't tuned a carb since the 70s (aka before I was born) and likely not a 4barrel for even longer. (He never liked 4brls and ran 2brls in his day.)

And the million dollar question: in EFI, you have a gas return line, in carb land, if the fuel pump sends too much gas, where does it go? (aka, this is why gas was everywhere?)

No other changes were made to the car. Only difference is a poor rebuild, on my part. What am I doing wrong? Help!

Aka, this weekend stunk. No Mustang driving for me.

The only good thing about this weekend, is I found a rather complete engine from a K code Vomit, I mean Comet (aka Mustang A code) with an Auto light 4100 on it (C5ZF-D!). Few parts missing from the engine and sadly, when I got the carb home (whole reason I bought the engine) on close inspection something seems to have been nesting in it. I think it will be ok, but is a long way from saving me from this Holley. (I really wish I had gotten into Comets, but the bodywork on those is no fun and my dad had a mustang, not a Comet in the 60s.)

Sorry for the long post. It has been a long days with ups and downs on this carb rebuild.

 

[zookeeper]

A carb rebuild may seem intimidating, but if you know what each part does, then when it needs fixing, you know where to look for a problem. I can't even begin to imagine what you did wrong because I can't see your carb, nor do I know what you did or didn't do. But here's some guidelines that I use, and so far, they have proven 100% succesful. First off, determine if the carb is even worth a rebuild. If it's something I bought new, or I know who did, then it's likely just in need of a thorough cleaning and new parts. If it came on the car or I got it from a friend or bought it used, then (in my experience) the only thing that's unfixable (aside from damage) is a loose/worn throttle shaft. If you can move it very much at all, the whole carb is (again, in my opinion) not worth the time and money to rebuild. But, if the throttle shaft is good and does not have too much freeplay, it's not a problem. The first step should be a clean area to disassemble the carb. I start by squirting Brake-Kleen (not carb cleaner) over the carb to get as much crap off the ouside as I can. It's VERY important to wear safety glasses when using ANY aeresol cleaner, because as sure as anything it can and will blow into a blind hole and back into your eyes. Trust me, that stuff STINGS. Anyway, once it's all clean, lay out some white towels to work on. I use Bounty paper towels because they're tough and absorbant. Trying to rebuild the carb on a cluttered bench, or on the floor, or in your lap won't cut it. I remove the front bowl, then clean it thorughly by using Brake-Kleen and compressed air in every port. Then rebuild the accel pump, replace the needle, check the float level and then set it aside. Then remove the metering block, disassemble it, clean EVERY port with cleaner and air, replace the power valve and the jets and set it aside. Then remove the rear bowl and clean it, then set it aside. Next is the secondary metering plate, disassemble, clean, reassemble with a new gasket and set it aside. Now is the part where I differ from lots of carb rebuilders. I don't remove the choke or the base. I have never had a problem or a leak from the base-body gasket, and since there's no gas carried in the base, I just squirt Brake-Kleen into EVERY port, both vacuum and gas and blow them ALL out with compressed air. Now that everything's clean, it's just a matter of CAREFUL reassembly. Make sure the metering block gasket is the right one and is located correctly on the pins of the metering block. Make sure you don't pinch the bowl gasket. Use Vaseline on the o-rings on the balance tube. Make sure everything is clean, and above all else TAKE YOUR TIME!!!!! This is not a timed event, there is no award being offered for the "World's Fastest Carb Rebuild".
As for some of your other questions, there is no return line on a carb because it's not necessary. Just like the toilet in your house, once the gas rises to the proper level in the bowls, the float presses on the needle, which closes the needle to incoming gas, only letting it in when one of two events takes place;, either the fuel level in the bowl drops, allowing the float to drop and the needle to open, allowing more gas in, or when excessive fuel pressure forces more fuel into the carb by overcoming the resistance of the float/needle assembly. When that happens, the fuel rises until it reaches the bowl vent, then goes out the vent.
The idle mixture screws should be GENTLY bottomed out (you did remove them and blow out the ports when you had the metering block off, didn't you?), the opened one and a half turns to start. If they need to be opened more than that just to get the car to idle, something else is wrong.
You now have two choices, take the carb apart and try again, being more careful this time, or chuck it and buy a new carb.

 

[woodsnake]

Float adjustment? Did you check/adjust/verify?

 

[runawayabc123]

Well, the condition of the carb before it was rebuilt, it was worth rebuilding. With what it is doing now... well it angers me. (It worked, everything free moving, not stuck and mininal slop. It just leaked gas through the gaskets due to age. During tear down, the vac sec diagham was totally shot and replaced.)

My dad and I spent over 8 hours puting the thing back together comparing old gaskets to new for best fit and checking pictures from before.

Yes, I took out both idle mixture screws, cleaned them out and sparyed air through to make sure they aren't plugged. But, like I said, they are hanging way out. I'll try correcting that next. Also, it doesn't have a secondary metering block. So, only one set of idle mixture screws.

I checked that both floats floated when it was apart and that freely moved to close the needles once put back in the float bowls. (My dad was chasing down this as the problem and bent the secondary float to close the needle and seat real fast.)

By the way the gas is coming out the top, it is the gas forcing right through the needle and seat. (It is coming up with pressure, not just free flowing.) Which is why I asked about the return line from EFI and... where the gas goes.

 

[D.Hearne]

From your description, you did everything wrong. Your question should have been, what did I do right? The throttle butterfly's shouldn't have been dissassembled, they're off centered now in the shafts, and I'll bet the screws holding them in now will come loose with time. At that time, one or more of the blades and screws will get sucked into a cylinder and do it's damage. The idle screws need only screwing all the way in, then back out 1-1/2 turns. The needle/seat adjustment, you had ass backwards. All the way down is fuel level down, all the way up is bowl full. The float hanger should not also have been bent. My advice to you is buy a new carb and keep your Dad as far away from it as possible. And once the initial adjustments to the new carb have been made by someone who knows what he's doing, keep YOUR hands away from it too.

 

[runawayabc123]

and I'll bet the screws holding them in now will come loose with time. At that time, one or more of the blades and screws will get sucked into a cylinder and do it's damage.

No, we tapped out the back of the screws so they won't come loose.

I'll be honest, your post sounds a little harsh. (Please note, I am not saying you are wrong.)

 

[runawayabc123]

The needle/seat adjustment, you had ass backwards. All the way down is fuel level down, all the way up is bowl full.

I am sorry, I described this part poorly, it was turned too far up to allow fuel into the seat (think way too far up). The port was in the threads instead of the far enough down to allow gas into it. I turned it way down relative to being way too far up. It still has lots of space to go further down.

 

[runawayabc123]

I talked to my dad and he said he did set the idle mix screws all the way in and 1-1/4 turn back out. But, they look a lot further out than from before it was rebuilt.

 

[gjz30075]

The problems:
The throttle seems a little sticky (aka, the round discs don't move as freely as they did before hand... over boiled, burs, I don't know?) Seems tolerable... but would be nice if fixed. It is sticky on opening from fully closed, otherwise fine.

Agree with Hearne on this one. Although you peened over the end of the screws to keep them from coming loose, the disc isn't centered in the hole. You'll have to loosen the screws again and play with the discs to get them centered.

 

[runawayabc123]

Tried adjusting the idle mix screws again, no improvement.

I think maybe the vac secondary needle/seat is shot (the kit included two pumper needle/seats, whereas this one is a vac sec only so the kit had no replacement for it). It moved ok, but maybe ok isn't good enough.

I'll also try recentering the discs. I had a picture of where each went and played with getting it all happy for an hour when I first put it back together. On the work bench it worked happy, just with the linkage/spring slaming it back made it sticky.

Oh well. Time for a re-tear down.

I didn't think this rebuild (being my first) was going to go well, but I hoped it would go better than this. I have yet to find a carb shop where I live and didn't want to ship it off as I wanted to learn about them. (I don't want to be a turn key driver.)

At least all of this happened on a carb I didn't plan on using for more than another month or two anyway.

Thanks for all of the help.

 

[D.Hearne]

No, we tapped out the back of the screws so they won't come loose.

I'll be honest, your post sounds a little harsh. (Please note, I am not saying you are wrong.)

Didn't mean to sound harsh, but with the lengthly post you started with, I figured you needed a reality check to snap some sense into you. Another part of the problem was too many irons in the fire (or so it sounded to me) Too many hands doing too many things here. I still think you need to start with a newer carb that's been untouched. You can always tinker with the disaster you have now, to learn on. And on doing a rebuild, another thing needs to happen......soak the main body and metering blocks for at least 24 hrs, then on removal from the cleaning solution, blow out the passages (all of them) with spray carb cleaner (wear eye protection for this) to insure all passages are clear, then blow again with compressed air (eye protection), then verify the metering block gaskets are installed correctly and no passages are covered (they'll go on two ways, only one's correct) and there are included with each kit, more gaskets than needed, not all are correct for your carb model. So be sure the correct gaskets are used.

 

[runawayabc123]

Another part of the problem was too many irons in the fire (or so it sounded to me) Too many hands doing too many things here.

You are exactly right here. When I was taking it apart, I was taking my time trying to remember what goes where with some pictures too. (I knew I was going to be very green on this one.) Then all of the sudden my brother and dad started picking things up and taking things apart. Let's leave it at, I didn't take apart either float bowl. (My brother likes to come around and help every now and then. Partly due to being a bike mechanic and this is his busy season, but sometimes he hurts more than helps.)

I'll be honest, I don't have a clue as to how this holley (or most carbs) works. I am trying to learn, but these things are hard.

Many mistakes were made. It was a learning carb. Since this carb it too big for the engine anyway that is why I wanted to rebuild it, because it was a "throw away" carb to our build. If things went super bad (as they did)... I knew I wasn't planning on using it again anyway.

We did soak it and blow all of the passages out (doesn't mean I didn't miss any), but not for 24 hours. I'll have to try that again.

I have a question as to the secondary needle and seat: This link shows a picture of needle and seats (big pile): http://www.aedperformance.com/Replacement%20Parts.htm which the rebuild kit has two of. This is what the primary one looked like as well. The secondary is half the size and just screwed into a mouting spot on the top of the float bowl (not adjustable or even viewable from the outside). No screw/nut is on this one like the primary, nor does it even have that top part. (This is why the float was bent, to adjust this needle and seat which seems unadjustable.) Any clue where I could get this part? (or what I am even talking about?) I think the carb is a paper weight without a replacement needle and seat for the secondary. I'll see if I can get my dad to take a picture of it and email it to me to post as I am at home now.

 

[wild70stang]

When my brother was rebuilding his autolite 2100 the first problem he experienced was the fuel spilling out of the carb. This was easily fixed because he FORGOT the gasket for the needle seat! You might want to check if this is in place or loose because this will cause the bowl to fill with excess fuel and flood your engine. Also like zookeeper said, check the float level or if its sitting properly.

 

[woodsnake]

I tried to rebuild a stock Ford 2V when I was a teenager. It didn't work so well.

A Holley 4V, however, is a lot easier, IMHO. Get a clean work space, take it back apart. Seperate out the components, and work in sub assemblies. It only takes one person to take it apart. What kind of reference material do you have to work from?

Anything like this?

http://www.tocmp.com/manuals/Carbs/Holley/TypicalViews/images/ExplodedDiagrams_0052.jpg

 

[D.Hearne]

You are exactly right here. When I was taking it apart, I was taking my time trying to remember what goes where with some pictures too. (I knew I was going to be very green on this one.) Then all of the sudden my brother and dad started picking things up and taking things apart. Let's leave it at, I didn't take apart either float bowl. (My brother likes to come around and help every now and then. Partly due to being a bike mechanic and this is his busy season, but sometimes he hurts more than helps.)

I'll be honest, I don't have a clue as to how this holley (or most carbs) works. I am trying to learn, but these things are hard.

Many mistakes were made. It was a learning carb. Since this carb it too big for the engine anyway that is why I wanted to rebuild it, because it was a "throw away" carb to our build. If things went super bad (as they did)... I knew I wasn't planning on using it again anyway.

We did soak it and blow all of the passages out (doesn't mean I didn't miss any), but not for 24 hours. I'll have to try that again.

I have a question as to the secondary needle and seat: This link shows a picture of needle and seats (big pile): http://www.aedperformance.com/Replacement%20Parts.htm which the rebuild kit has two of. This is what the primary one looked like as well. The secondary is half the size and just screwed into a mouting spot on the top of the float bowl (not adjustable or even viewable from the outside). No screw/nut is on this one like the primary, nor does it even have that top part. (This is why the float was bent, to adjust this needle and seat which seems unadjustable.) Any clue where I could get this part? (or what I am even talking about?) I think the carb is a paper weight without a replacement needle and seat for the secondary. I'll see if I can get my dad to take a picture of it and email it to me to post as I am at home now.

For starters, I don't know which Holley you're working on. But usually they use the same needle/seats on both bowls. I have heard of some that have non adjustable needle/seats, but haven't come across one. As for the adjustable ones, I take em and hold it upside down after installing the needle/seat and adjust it till the float is parallel & level to the roof. Once done, I usually never have to adjust em after the carb is installed and running. If you really want to learn how they work, buy a book and read it. I've got a "Haynes" Holley carb Manual, it's pretty well worth the money spent.

 

[runawayabc123]

My dad got the car running with the primary side ok, but the secondary side still flooded.

When my brother was rebuilding his autolite 2100 the first problem he experienced was the fuel spilling out of the carb. This was easily fixed because he FORGOT the gasket for the needle seat!

I think this may be on track. The only gasket that fit the secondary needle and seat was extremely lame looking and poor fiting. I am starting to think the rebuild kit I have is sub-par at best.

I have the same exploded diagram in paper, but it doesn't match the secondary side of the carb.

Maybe Holley was on to something when they told me that they had no rebuild kits/parts for my carb and so I ended up going aftermarket.

 

[runawayabc123]

Found it! http://www.partsamerica.com/productdetail.aspx?MfrCode=HOL&MfrPartNumber=6511&CategoryCode=3338Z

This is the secondary needle and seat in the carb.

 

[D.Hearne]

Looks like an Autolite 2100/4100 needle/seat. You would have to bend the float hanger to adjust it, same as an Autolite.

 

[runawayabc123]

Final update on this to put this thread to rest, I replaced that wimpy gasket on the non-adjustable needle and seat with a rubber o ring, made sure the primay side was locked in tight, adjusted the throttle plates which fixed the sticking 100 percent. Tossed it on and all of the problems are fixed. It runs a million times better than before the rebuild. So, wild70stang had the right idea.

Thanks for everyone's help.