Edelbrock Carb on 454 Help

[Desert_Eagle02]

Hi guys, I recently noticed this problem. I have an Edelbrock 1411 750 CFM with electric choke on a 454. I think it is running rich. It smells very exhausty when it runs, and studders slightly when you give it a decent amount of throttle while driving when it is warmed up. Also seems to be going through fuel faster than usual. And it can be a little hard starting when warm also. When it is cold it fire's right up no problem. I haven't messed with carbs since I was in highschool and even then my truck really never need carb work. So is there anything I can try to adjust to tune it in, or perhaps just a cleaning or a rebuild kit or something? Any help will be appreciated thanks.

[geezer#99]

You likely need a fuel pressure regulator that's set at 5 psi.
Eddy carbs don't like more than that.
One like this that has a max rating of 5.5 works.
https://www.summitracing.com/int/par...2518/overview/

[Desert_Eagle02]

Ok thanks I'll look into that. It does have an electric fuel pump

[geezer#99]

THen you should look for a return style reg that sends fuel back to the tank.
Electric pumps don't like to be deadheaded.

[Desert_Eagle02]

Thanks for the info I'll look into those. Not sure what is currently on it.

[tucsonjwt]

I would check the usual suspect first. Make sure that the choke valve is all the way open when the engine is warm. Others here are experts on choke adjustment. I never had a choke (electric, divorced, or hot air) work properly for me, so I always converted my vehicles to a manual choke - I never wonder if the choke is open or closed.

[Desert_Eagle02]

Originally Posted by tucsonjwt

I would check the usual suspect first. Make sure that the choke valve is all the way open when the engine is warm. Others here are experts on choke adjustment. I never had a choke (electric, divorced, or hot air) work properly for me, so I always converted my vehicles to a manual choke - I never wonder if the choke is open or closed.

Ok thanks I'll check to see if the choke is functioning properly and all the way. Maybe I'll convert it to manual.

[raggedjim]

Also, if you have a big cam you may not be overcoming the primary idle circuit spring pressure at idle. I believe there are weaker springs designed for engines with low vacuum at idle.

Good luck, Rg

[Dead Parrot]

After checking the choke, PVC and verifying no vacuum leaks, consider installing a rebuild kit. Also research the best jets, rods and springs for your engine and application. Pickup a couple of cans of carb cleaner to give the carb a good cleaning. Some local box stores carry the rebuild kit. I got mine from O'Reillys.

Make sure you have a 7/16" twist drill bit or 7/16" round metal stock. Used during setting float levels. Most of the time, the float levels out of the box are wrong and make it easier for the carb to flood.

If you have an old style vacuum gauge, they often have a fuel pressure range as well. If your fuel pressure isn't too bad, see if setting the float levels fixes the flooding problem.

While you have it open, see what jets, metering rods and springs are installed. If they are a ways off from what your research indicated for your application, order the proper parts + a new airhorn gasket(in case you mess the one on the carb up changing the jets.) If your only changes are rods and/or springs, you won't need the new gasket. I was able to get some new rods overnight from O'Reillys so if you can wait for the new parts to arrive before assembling your carb, you can skip the new gasket.

[Desert_Eagle02]

Well I finally have some time to start working on the truck. I picked up a rebuild kit, new floats, an Edelbrock spacer (on hot days when the engine is hot, it can be hard to start. I was told this should help quite a bit) and a new fuel filter. Looking over the carb before I take it off I notice the pcv fitting in the carb is capped off. I look at the valve covers and it has an oil breather on each side. I don't know why I never noticed this before.

So should I buy a valve and hook it up? Would the current setup make it run a bit richer, since it's not getting as much air as it would if it was installed?

[RotaryRocketeer]

Keep in mind that any Edelbrock that comes with electric choke is calibrated for economy rather than performance. because of this, I doubt the issues you're having are resulting from the carb being calibrated too rich. More likely, as mentioned before, fuel pressure is slightly too high and floats are set incorrectly. They should hang 7/16" from the horn at full droop and come up no closer than 3/16" to the horn when all the way up. Both of my Edelbrock carbs had floats that were waaaayyy out of spec. Setting the choke position is as easy as pie. Plenty of instructional videos out there.

PCV valve can't hurt either. $3.99 at your local auto parts store.

[Dead Parrot]

PCV is good, keeps a lot of the blowby crap from contaminating your oil.

Do the valve covers have a rubber plug where a PCV valve might go? Wondering if one of those breathers is really where the oil fill cap goes.

Be sure the PCV valve is on the side of the motor opposite the breather you leave in place.

Post up your jets, rods and springs currently installed. Maybe a 454 expert can offer advice on what should work well for you. If a PO installed that carb, no telling what it might have in it.

[akart]

Also pick up a calibration kit EDL 1489. It contains metering rods,set up springs and jets. All you can adjust without it is the idle mixture and idle speed. With the kit you can adjust the fuel for mid rang cruse and full open and accleration. The 5.5 lbs pressure is a must. Edelbrock also makes a mechanical fuel pump if it fits on your engine. I did this stuff w/my 1405 carb on my 350,works great.

[Desert_Eagle02]

Ok I'm going to pick up a pcv valve today. The valve covers have have a breather and oil fill cap on each side.

I have the carb off and I'm going to start disassembling it tonight. I'm a little nervous about it as I've never took a car or truck carb apart before. Just motorcycles. I'll post what the jets, rods, and springs are currently in it. Who knows what the setup is right now. I also noticed the vacuum advance for the distributer is connected to the timed port and the manifold port is capped on the front of the carb. This truck has no emissions on it, so shouldn't it be on the manifold vacuum port?

The electric fuel pump is a Carter pump. Not sure which model it is, I couldn't find a number on it anywhere, unless it is covered by the mounting bracket. And there is no fuel pressure regulator installed so I'm going to pick one up from Summit and adjust it to 5.5 psi. There is no return line on the pump so will the regulator be hard on the pump or will it be fine?

[wilkin250r]

I've heard arguments both ways for the ported vs manifold vacuum debate. I've heard some claim the manifold vacuum causes overheating at idle, I've heard some claim that ported vacuum causes overheating.

Most technical articles (not forum debates) will claim the ported vacuum was an attempt to improve emissions by increased exhaust temperature, but it comes at a price. The theory being that with the delayed spark, the fuel/air was still burning as it left the combustion chamber, past the valves, and out the headers. That extra heat improved the performance of catalytic converters and other emmission-reduction methods (with the obvious side effects of increased risk of burning valves and warping heads)

I know all of my carbureted engines seem to run best off manifold vacuum.

[RotaryRocketeer]

Originally Posted by Desert_Eagle02

I also noticed the vacuum advance for the distributer is connected to the timed port and the manifold port is capped on the front of the carb. This truck has no emissions on it, so shouldn't it be on the manifold vacuum port?

Let's not start that debate haha. There are plenty of pissing matches you can read where they talk about it to no end. Some setups like full manifold, some don't. I run full manifold, but I'm positive that someone here thinks that's stupid.

[Dead Parrot]

I doubt the presence or absence of a regulator will matter to the pump. It will put out the same pressure either way. The only difference is what pressure the float seat in the carb sees.

I use the manifold port for mine but try both and use whichever one works best on yours.

Save all of the used little clips, springs, filters etc.

While a lot of folks claim a regulator is a must, I have yet to need one with my 1405. Been through 3 different mechanical fuel pumps. Either I have been lucky or the carbs will tolerate some over pressure.

[rickit]

I'm having the same exact problem with my edelbrock only I have a 455 olds rocket in mine and I have a mechanical fuel pump

[Desert_Eagle02]

Alright. I'm going to soak the carb and parts in cleaner tomorrow and reassemble and install the half inch spacer. Install the pcv valve and a new breather on the other side. I ordered a fuel pressure regulator from Summit, already installed a new fuel filter.

I'm going to switch the vacuum advance to the manifold port and see how it runs on that. I assume I'm going to have to adjust the idle after switching ports. Perhaps the timing too?

If everything goes good I should have it all together by Sunday night. I'll post which springs, rods, and jets that are in the carb. I'm going to try them with the new setup, before I start experimenting with a kit to dial it in if need be. Hopefully it all goes good. Thanks everyone for the help. I really appreciate it.

[Desert_Eagle02]

One quick question. Last night I reassembled my carb. It all went very good just want to make sure I got the accelerator pump stuff installed correctly. When I disassembled it, it had the little ball, and a spring on top of it, no weight. The instructions said to install the new ball, and the new weight, it did not say anything about the new spring which was included in the kit too. The few different videos I watched showed they installed the ball, weight, and the spring. So that's what I did. I just want to make sure if that is correct, or is the spring not needed, or should I have done the ball and spring, and no weight like it was before I rebuilt it.


*Edit*
I ended up taking out the spring and using just the weight and ball. It runs a lot smoother now. Just waiting for the fuel pressure regulator and pcv valve to come now.

[RotaryRocketeer]

As in any case, it's whatever works best for your application, but that spring is an integral part of the accelerator pump's operation. It will keep it from binding up in the hole. The upward pressure applied by the spring makes sure that the plunger returns to the home position when its work is done. Just my $.02.

[wilkin250r]

I have a feeling it's one or the other, but not both.

I don't see any reference to a spring in the Owners manual, I'll try to dig out my old Edelbrock Rebuild and Tuning guide tonight, see if I can find any mention.

In any case, the Accelerator pump should only activated when the throttle is opened rapidly, and you can easily test this (even on a bench) by filling the float bowls, and then quickly actuating the throttle. You can visually see a healthy squirt of fuel into the secondaries. Worst case scenario, try the different configurations and see which one works best.

[Desert_Eagle02]

That's what ideas thinking, one or the other. I have just the weight and ball installed right now, I'll see how that runs.

I installed the pcv valve and a new breather/filter on the other valve cover. Then changed the vacuum line to manifold vacuum. I turned the idle mixture screws in all the way and backed them out a turn and a half. It seems to be running great. I let it idle till it was at normal temperature and then set the idle screw down a bit to a nice idle. I haven't installed the fuel pressure regulator yet, just got it today and I see I need a brass fitting to cap one of the 2 fuel output ports. So I need to pick one up. I'm not able to take it for a test drive right now, since the barn shop I've been working on it in is on a dirt road and it's been raining the last couple days so the roads are a mess.

Another question though, since I changed over to manifold vacuum, do I have to mess with the timing at all or should it be fine?. It seems to be running great by just switching it over from ported. But I don't want to cause any damage by having the timing off.

[wilkin250r]

I do recall that Edelbrock makes an offroad version of these carbs. While I don't know all the exact changes, I would imagine that a spring in place of a weight would probably be the the exact type of alteration that would make it more suitable to being bounced around.

[RotaryRocketeer]

Nevermind. I was picturing the accelerator pump plunger return spring. Couldn't think of a reason why anyone would think they could run without it haha.