rcknrolfender79

Hey guys, my just curious which is best? I've heard that an Edelbrock is best to run on a mopar. And on my challenger a it seems to run better with a 650 edelbrock than it does with a 650 holley. But thats on a 318. My Coronet R/T has a Holley double pumper on it not sure what cfm though haven't looked it up yet. I just started having problems with it running a couple weeks ago. It was running great then all of a sudden it just started crapping out and missing like crazy. Parked it then got back in it and took off and it was running fine again for a few days then out of no where it does it again. Now it has gotten to the point to where I can count on it crapping out. I have replaced the fuel filter, plugs wires, rotor bug, distributor cap, and put some heet in it to make sure it doesn't have water in the tank. I'm now down to thinking its either got crap in the gas tank or the carb is in need of attention. It runs fine at idle with stress and will usually run fine til it gets warmed up. It has an aftermarket intake with a bit of a higher rise than stock so I don't think it could be vapor locking. If after I drop the tank and I happen to find it is clean I'm either going to do a rebuild on the holley or go with a different carb all together. Which is better? I've heard Demon carbs are excellent. But after seeing how much better the Edelbrock ran on my challenger I'm a bit biased. Also how much CFM should I go with on the 440? Right now as far as a I know its a stock motor out of a 68 police car. In the future I may put some aluminum heads and a little bigger cam. But thats about it. Not ever going to be a race car just a fun street car. I was thinking 850 cfm.

TVLynn

Sounds like crappy gas. Drain some into a can and look for water. Talk the carb apart and give it a quick cleaning
Otherwise dump a good dose of SeaFoam into the gas tank and run it

Gorts 5th

sounds like ethanol again i put my hollies on the shelf run a edy 650 avs on my 318
other than the heat soak boil overs she is fine
but my hollies had a lot of issues i blame on ethanol
i would really love to try my 650 dp, purchase a trick kit and woo hoo!

PURPLE HORONET

A carb either works or it dont work.. The problems are from people letting them sit and gum up or get trash and water in the fuel.. Yes the ethnol does harm the gaskets, But I have only seen this from carbs that are left sitting on cars and boats for months at a time with out being run.. I have four wheelers, boats, cars, chain saws and other crap that sits. The only problem I have found with ethnol is it made things run leaner and it cant be left sitting around very long like normal gas.

Gorts 5th

my hollie issues started with the introduction of ethanol first thing i noticed was the lean condition then different stations have different % of ethanol and then the stuff messes with the main holding tank at the station, water or concentrated levels of the stuff. hard to jet for inconsistent fuel
then the gaskets started failing not just leaking but they where soaked with fuel...but not as much as the power valves they would go to ***** in a few months, hell i put one in and by the end of the day it was leaking.
i ran hollies for years today i'm not so inclined.

pro-tech

If you put Star-tron fuel additive in it eliminates all the problems you a discribing it is an enzyme and removes the ethanol unlike fuel stabil. TRY IT YOU"LL LIKE IT MIKEY. Esp in storeage like snowmobiles. My sled sat for 2 years it started up and ran fine on the ethanol fuel treated with Star-tron that was in it.

bigblock

Could be the ignition module. I had one of the orange boxes do that same thing.

moe7404

a 1968 HP 440 would have a carter AVS. worked on lots of them. some have a flat spot off idle. easy to fix. the AVS is a very good carb.

Moparod

Purely a matter of preference. In my opinion you couldn't pay me enough money to put a Holley on my car. True, easy to set up and get running right but they don't stay that way. I've never had a Holley that I didn't have to put a screwdriver to at least once a month. The last Holley carb I owned was in 1990. Edelbrocks and Carters, they are a little more work to get right but when you do you never have to touch them again. Now my best friend is just the opposite, he swears by Holleys, won't run an Edelbrock.

PURPLE HORONET

I have no problems with holleys, and if one is set up correct it will give you years of trouble free service like any other carb. I dont understand people saying they need to adjust their holley once a month or all the time. I must have a golden horese shoe up my rear. Because after I set one up I never touch it again. I agree the ethanol did make things run leaner.

If somebody does not now how to supertune a holley the eddy carbs with electric choke is the best way to go. If I buy something to sell and it needs a carb a eddy is what it gets. But if I want a true performer a Holley hands down...

Moparod

Different strokes...

Gorts 5th

what's that trick?

Gorts 5th

as far as hollies being easier to set up...no not really
i feel the eddy is the easiest to tune or should i say the quickest.

i would really love to try my 650 dp on ol girl. 318, cam 275 284-462 482 eddy air gap 360 heads ported 1.88 1.60 vales
this would be the scenario...any input is appreaciated.
the carb is apart in a wood box and what i mean by apart is its empty no parts but the main hard parts assembled loosely
Starting with a hollie trick kit
power valve around 6.5 hg
main jets 65-68
secondary jets 70-80
accelerator pump diagrams prime 30 cc. sec. 30- 50 cc
pump discharge nozzles main 25-31, secondary 31-37
accel pump cam well your guess is as good as mine... fast, slow, long, quick, early, late,
Power valves are usually pretty solid, 1/2 the idle vac
but the jets every swap is a major deal, remove the carb drain the and remove the bowls at least with the eddy you remove the top and every thing is there and the main rods are accessible with the top on takes a minute to swap rods
my set up in the eddy 650 avs, is 5 hg power valve, main jets 104 with 65/42 rods and secondary jets 101.

i ran holley in my early days when they had real gas
i know what the difference will be between the two when i mash the eddy to the floor the avs has to open
when i mash the holley it's open the differences will be in the out of the hole acceleration.
i would enjoy comparing the two...

moe7404

do this mod ONLY to 1968 and newer carter AVS. 67 and older carters do not need this mod. and only do it if the engine has a flat spot off idle. you need a pin vise for drill bits from #80 to # 61. and the drill bits. remove the primary venturi cluster. on the bottom is two brass tubes. use one drill at a time to check the, small tube, hole size, the small one is to be drilled out only by .001" hold the tube pointing down so the fillings fall out. slowly by hand drill the hole in the narrow spot. double check that no fillings are in the tubes.

rcknrolfender79

I'm not sure if it's crappy gas or not. It seems to me it would run bad all the time. As far as ethanol goes it could be. But it seems like ethanol would make it run bad all the time as well though wouldn't it? No matter how cold it is I can go out pump the gas twice and bump the key and its started and runs so smooth you would think its a brand new motor. You can put it in gear and take off and drive it for roughly 10 to 15 minutes (sometimes all day) without a problem. But eventually at some point its like someone is under the hood (maybe that trouble making insurance dude from the commercials lol) and they take a few plug wires off and dump water in the carb. It will also backfire, not constant it will just let off one excessively loud backfire out of no where. And when it starts running like that I have to park it for the rest of the day cause it won't run any better an hour later. It's very strange to me. But you go get in it the next morning and she purrs like a kitten again.

Gorts 5th

it sounds like your coil is getting hot and malfunctioning.
or you electronic pick up is out of adjustment or malfunctioning
what kind of ignition system?
Coils i have heard it all they work or not.

But in my experience had two fail after they would get hot they would have the same symptoms maybe it has some thing to due with tthermal expansion causing a short
Had a pertronix with a blaster coil came of the high way and she lost power and sputtered to a stop at the bottom of the ramp after about 10 minutes of trying to get her to run she made it home. after about two hours she started up ran like normal after 20 minutes did the same thing so on a hunch we swapped the coil for a spare we had and she ran fine, until i later replaced it with mallory system.
If you got a spare coil make sure it the right one for the system.

bigblock

What did I say about that ignition module again?

jacilynn_s

Love the comments so far.

A stock 68 motor will take a carter afb or avs. Which would be an eldebrock performer 600 cfm part #1406. The engine is an old and worn 10.25:1 compression engine with a magnum cam regular valves.

The carb itself comes with electric choke that can be unbolted and a regular choke put on or you can leave the electric choke and wire it in if you reallly want too. A test circuit for this would be using a thermo switch from the electric assist cars (73 +) bolted to intake with the power for it coming from the ballast resistor on the firewall. purple or blue wire can't remember just plug a wire around the tab to test it. If you wish to make it permanant there is a junction on this wire back in the engine harness that you can solder into.

A bad coil is usually wet around the cap or will drip fluid on the intake. Exchange it with a known good one if you wish. Plugs plug wires again if you wish but I suggest using original chrysler wires as they fit properly.

Ill make a guess your start the car and it runs great till it gets nice and warm. After that it smokes black out the rear and bucks like a bronco. This is usually a bad float in the carb flooding the engine with tons of fuel. Your choice what to do. It's that or your choke stays shut for some reason but that should be the first thing to spot with the air cleaner off.

rcknrolfender79

Sorry guys haven't been on in a couple days. To answer the questions about the coil, I put a new one on it already. The car has had a complete tune up. I took the 650 eddy off of my challenger and put it on the R/T today. I test drove it before swapping the carbs to see about how long it took to start crapping out. I didn't make it a block. I swapped the carbs and went for a test drive again, the car ran great aside from losing a lot of horsepower from going to the much smaller eddy. I drove it around the block, got on it and got it side ways. And drove about mile or so then. Brought it back home to get some money to go get a rebuild kit for the holley. Drove it down to the parts store and about 3 miles later... BUCK THUMP POW!!! I looked at the gas gauge and noticed it was almost empty I thought for sure it was just running out of gas. Luckily I was close to a pure gas (no ethanol) station. I pulled in filled it up. Started it up after a little hesitation. And took off. When I was about 3 blocks from my house it started crapping out really bad and completely died. After letting it set for about 30 minutes I FINALLY got it to start again and drove it missing and backfiring and scaring the crap out of everyone in the neighborhood lol. Finally got it home. My next step is to return the damn rebuild kit I bought and drop the tank and see how much crap is in it. That is the only thing I can figure. Its got a completely brand new tune up and fuel filter. The eddy was just rebuilt about 4 months ago. And Bigblock I will look into the ignition module. Hopefully its one of those things, this has gotten passed the point of being frustrating. I drove the damn car back home from Ohio to Tulsa, Ok without one damn problem! it was over 1000 miles! As soon as I get it home all of this starts happening. Its just torture to have just bought this car and not being able to do anything but set and look at it and wonder wtf is wrong lol.

Gorts 5th

what kind of distributor is on it i would see about replacing the electronic pick up as per "bigblock" earlier suggestion.

rcknrolfender79

It has points. Would it still have an ignition module? I haven't replaced the points on it.

Moparod

No, if you're still running points it wouldn't have an ignition module. One thing, heaven forbid, my 383 in my old '68 Charger had the same symptom crop up going home from cruise night back in the 90's, I had a cam failure. I had rolled a cam lobe on the POS Purple Shaft cam and had one cylinder that the exhaust valve wasn't opening. Popping and carrying on like a demon because the cylinder exhaust was trying to go out the intake valve. Got her home, I was within a mile and a half, next morning I pulled the valve cover and one of the rocker arms was flopping, pushrod was out from under it. Removed the pushrod and it had about a 15 degree bend in it. Popped the intake off and had a cam lobe that was round as a marble and a really cool looking lifter. Swapped in a Comp 270 Magnum cam and lifter set, changed the oil and put 55,000 miles on it by the time I sold the car in '02. Still running perfectly fine to this day...

Chryco Psycho

My Favorite is Proform , very well set up out of the box & very tunable to get the last out of it .

rcknrolfender79

Well that would be a bad day to find out it was the cam... lol. Lets hope not. Wouldn't it run bad constantly if a lobe were flattened on the cam?

I called and talked to a mechanic yesterday. He said its a really good chance its the fuel pump. He said he had a 69 dart with a 440 and had the exact same problem. Ended up being the fuel pump. So I think thats my next buy. I've got to make sure of whether its fuel or fire causing the issue before I buy anything else... If I keep it up at this pace I'll have replaced every part on the car except for the one that needs replaced until its restored lmao. I'll have to wait til monday though. Won't have any free time til then. I will be sure to let you guys know what I find out. And keep the suggestions coming. At this point I'm pretty well at a loss as to what the hell is wrong with it. But the fuel pump does make sense to me.

Gorts 5th

hell yea check the point's a set of worn points will do this! No .module
also if the distributor bushings are worn that will inter-fear with proper function ie. dwell... "gap"

Chryco Psycho

I assume this a big block ...... so pull the fuel pump pushrod & see if it is worn , the reduced diame=ter on each end should be the same length , often the pushrod will wear down again due to lack of ZDDP & will not cycle the pump fully

blue 68 gts

THANK YOU. Someone smart.

A holley is THE only way to go. Edlebrock and Carters are JUNK.

I had a Holley 650 dp on my car for years, hardly touched it. Just an old carb. Ran mid 11s with it on my 440. Put on a 750 that I've NEVER tuned. Right out of the box onto the engine. 11.30s.


I wouldn't go any bigger than a 750 carb on your motor. IF you're leaving it stock, 650. Theres no need for bigger than 750 until you're going 10s

blue 68 gts

Get rid of your points in favor of the orange box or MSD and electronic distributor.

rcknrolfender79

Well I got my fuel pump in today. I'm going to really try to determine the issue before I go ahead and replace it. I'm hoping its either points or the fuel pump. If it's not one of those I'm sad to say it's probably going to be the distributor and I really don't want to shell out that kind of money right now. I've been working a lot of over time and haven't had much time to get out and see what the issue is. But hopefully I'll get this friday off, if nothing comes up here at work. And I can get out and get this crap figured out once and for all.

duster3

I would check the gap on the points as well, if you have a dwell meter, USE IT! I just went through this with my rambler in the fall.

Not sure if this will fix your problem but you usually need to adjust them whenever you do an oil change lol seriously...maybe I just had bad luck with cheap points

In my experience if the points arent adjusted right, its not going to run correctly all the time..not just crap out randomly