Has anybody out there had this problem. Brand new 302 crate motor with trick flow heads. I put on my 1405 600cfm edelbrock carb and it runs flawlessly. After several miles it acts like it's running out of gas. I can't start it without keeping my foot into it. Let my foot off and it dies. Runs very rough. Take the top off the carb and clean it the best I can w/carb cleaner. I do see alot of metal shavings in the cleaner bucket. I put it back on and it runs great and then we go through this cycle again. Each time it gets worse. I'm at a lose as to the problem. I'm about to replace the carb, but I can't get myself to come up with another $250. I've already replaced the fuel pump, ran new fuel line and have run it out of my jerry can thinking I had a problem with the old plastic bronco fuel tank. Any help out there.............thanks jim from portland

 

Metal shavings? That doesn't sound good...where at,where from, where have they gone and going...?

 

Are they aluminum shavings like the carb material? Or are they magnetic (steel)? Did you completely clean out the carb including the jets and passages or just cleaned the float bowls? Do you have any type of filter between the pump and the carb? Is it possible that the filter may be coming apart internally? Was it a new carb that you installed?

When you used the temporary gas can, where did you run the new hose to? Right at the fuel pump?
It runs good at operating temp until you drive it for a while, or will it run poorly as soon as it is warmed up?

Jason

 

I believe the shavings were aluminum. Using a black oil pan to clean the carb, I could see them as silver and the gold color of the carb, if steel I wouldn't see them as much, very fine. I did read in edelbrock complaints of this. The motor ran great, it started this stalling like it would run out of gas, when warmed up and running for a few miles. It would start again and I would be able to drive it home. This lasted for a couple of trips. The last time it did the same thing but I couldn't keep it running unless I kept my foot into it. When I got it back I couldn't even start it. That's when I pulled the carb. Ran carb cleaner through every hole and jet even to the point of submerging it. Put it on, got it going with my foot in it, worked the fuel mixtures down to about 1000 rpm, which it held for a little while until stalling.........I'm at a lose, running it out of a can through the fuel pump just eliminated any problems with the old fuel lines, tank, tank switch. Thisis on a 69 bronco with alot of the orginal equip.

 

Don't rule out the fuel pump as the source for the shavings. If it is a new carb, you may be able to return it for another if you suspect that is where it is coming from. Do you have a fuel filter between the pump and the carb? May be a good idea to diagnose your problem and just for future preventative maintenance. You said that when it acts up, it runs rough. Is that at all RPM's or just when you can get it to idle?

Jason

 

If you use a filter with a clear housing between the pump and carb this should tell you where the shavings are coming from. By the way, DITCH THE EDELBROCK CARB.
Edelbrock is a reputable company, but their carburators don't belong on anything with a performance motor and/or transfercase. Thunder series with springloaded needle and seat helps nothing on hills or inclines, maybe rough terain at speed.

 

In my last post I don't think I clearly expressed my dislike of the Edelbrock Carbs. They will get your truck stuck, rolled, flipped and $10,000 on funniest home utube.
On the street they will cost at lest 30hp on your 302, more on a 351W.

Now on to your original question, Yes metal shavings going into your motor is a bad thing. Filter it and then sell the carb to someone that belongs in hell and buy a Holley.

 

Edelbrocks aren't bad for a wheeling carb. But just like a Holley, they don't work right out of the box. There are a few tricks to do to make them perform on the trail. The only thing that the spring loaded needle and seats offer is dampening from high speed bumps. They do nothing for dealing with angles as you said.

If you're looking for the best off road carb, it is hard to beat a QuadraJet. The float bowls and passages are designed well and don't suffer from fuel spill-over or starvation. They offer several different CFM's to suit any need. They get a bad rap from the hot rod scene because of lack of knowledge in building and adjusting them. And buying a mass produced parts store rebuild doesn't compare to rebuilding an untouched wrecking yard carb.

Jason

 

RC, You are the go to man for a lot of answers on here.
In my research I never found any company or individual that made the Edelbrock work off road.
What specificaly can you do to make it work?
And as for peak HP and Torq numbers on a performance V-8 why screw around with the Edelbrock when the Holley Truck avenger runs so well right out of the box?
I spent a lot of time with a tune kit for the Performer carb, reading and changing needles, springs and jets and kept notes of changes. I ran a manifold vacume gauge into the cab to help with the process. NO Luck!
The Holley made My 68 want to go sideways on dry pavement in second gear, out of the box. NO comparison. In my opion the Holley wins hands down.

 

I had the opportunity to work for a guy who was a genius when it came to setting up carbs and fuel systems on stock and performance applications. In fact, I still take my own stuff to him for tweaking.

The biggest mod that you can do is isolate the float bowls. There is a passage that runs between them at one end of the carb. What happens is when you get off camber, the fuel wants to flow to the downhill side which then causes it to overflow and flood. To make matters worse, now the empty float bowl is trying to fill again and making things worse. We fixed the problem by epoxying a piece of sheet metal or aluminum in the middle to block the fuel flow. And then drop the float level depending on the supply needs. We may start out with 1/8"- 1/4" lower and see how it responds. Jet it as normal, and pick the metering rods so that the transition in the steps is subtle. What you are trying to accomplish is to give it just enough fuel that it needs without overfueling it, and without undershooting it and making too lean under full power (bad news).

In other cases, he has even tried to isolate the float bowl inlet to allow fuel to flow out of it a little slower to control up and down hill angles and sudden movements.

 

Good info Rc, that explains why Holley uses dual feed inlets. I know a guy that can't aford a new carb. I will see if he wants to pull it a part and try the mod. It's his carb, what have I got to loose?

 

I hit the wrong button and sent my post too quick.

Setting up a carb for extreme angles and off road use is different from setting up strictly for power and street performance. Finding the compromise between them is the trick. However you will sacrifice a little in either area to accomplish that.

If you pulled the Holley out of the box and made it work with very few changes, then that is great. You just happened on the right combination between your engine combo and carb. I had a co worker that bought a Truck Avenger for his Bronco (with a 351) and he spent lots of time trying to get it dialed in for the street. But the first time we went four wheeling, he realized that he had more work to do on it.

I don't think that there is a power disadvantage between a Holley and an Edelbrock of similar CFM ratings. I am using a 750 CFM Edelbrock to feed a 427 BB Chevy in my 71. I'm expecting a little over 600 hp with 9.5 to 1 compression, iron heads, and 92 octane according to my dyno program. Any hp difference between carbs should be negliable. But this pickup has been sitting half built for 15 years, so by the time it is finished, I should be retired, on social security (which won't exist anymore) and I won't be able to afford to drive it.

I think the big advantage in the Holley is the ease of jetting changes and adjustments. Makes fine tuning for track conditions very quick and painless.

Jason

 

I need to check in more often. This is great stuff guys. I have read so many times that Holley is the way to go right out of the box. For the normal backyard mechanic... Would you agree to just buy a Holley and bolt it on?

 

Done did, runs great.............holly

 

RC is right about the compomise between street performance and off road. But with the Holley Truck Avenger just changing the vacume secondary spring helps a lot with this. For further tuning a manifold vacume gauge will help with powerjet selection.
After that, checking spark plugs for color will tell you how your primary jets are for size. But yes they do run well right out of the box if you DON"T buy a size too big. For primary off road use the 570 will work very well on most 302-351 engines up to 5500rpm.