OK, some background- my car is a 70 Challenger that I bought about 10 years ago and has a crate 426 hemi in it. The problem is it will start and run fine for about 5 miles and then it will stall when I slow down and miss terribly from then on. This has been a recurring problem ever since I bought it. This first happened not long after I bought it. At that time I took the carb off thinking it had some dirt in it and when I put it back on the car it ran fine for a long time and I thought I had it fixed. Recently it started acting up again so I took the carb off and saw some dirt in it so I cleaned it out and put it back on the car but the car is still stalling. I've replaced the fuel filter so that can't be the problem. The carbs are Edelbrocks, 1405 on the front and a 1406 on the rear. I'm wondering if I should get rid of those carbs and put on some Holleys?? Anyone have any suggestions?? Help!!

1st thing sell me the car for 1 dollar.

Sounds like flooding.
Fuel pressure?
Float levels?

I'm thinking it floods and fouls plugs and never runs right afterwards.
Could be heat related effecting fuel too.
Hot fuel ...line too close to exhaust
Foam and bubbles will flood the carb too.
Needle and seat can't control foam.

I had a similar situation many years ago.
Fuel was too hot...flooded carbs at random times.

What were the conditions when it was OK and not OK?
Traffic idling. Come to a stop after distance?

Could be ignition.. a dist pick up breaking down
under heat.. I had one do that till it just quit

This has been bandied about repeatedly here...


Here's my recipe for 20+ years of success with a street-driven Edelbrock...


Isolate the carb from the manifold(as in spacer)...

Make sure delivery AND return are dialed-in properly...

Mix your fuel with REAL fuel(as in Torco, Cam-2, whatever)...


Been doing this for many moons, zero issues...

I vote for Holley`s all the way..............they look and perform WAY better in my opinion......

I vote on Holley type carbs also but with the Edelbrock there should be no reason to mix race gas unless the fuel in your area is known for being bad.

My car has pretty much ran great all summer but I've had an intermittent problem like yours where it will stumble and stall and not run right. After alot of parts blaming and parts changing I finally watched the carb closely the other day and the rear bowl would just fill up and drip out of the boosters. My fuel pressure was at 7 but I have a cheapo gauge, so I backed it down to 5.5 pounds and the car runs perfect, simple fix on mine.

Good luck with it.

Exactly. ..sounds like flooding. .nice work Bob

Here`s the deal...............NEW tech......bigger n&s`s and lower pressures is the hot ticket these days and check out the Quickfuel bowl fuel entry and notice the smooth transition NOT the big azz wall the fuel hits on it`s way into the bowl. Aeration in NOT our friend in the bowl so, on 4150`s I use a minimum of a .120 n&s and no more than 7 psi and dommies get a .130 and no more than 6 psi...........try it you may be surprised. Just did a dommy and it was JACKED w/a .110 n&s and many more issues........should fly now.

The car ran fine the last couple of years and also earlier this summer. It started acting up about a month ago. Today it started fine and ran fine for about 5 or 6 miles and then it started stalling every time I slowed down and would miss badly on acceleration but seemed to smooth out once I got to 45-50 mph cruising speed. I set the float levels in the primary carb so that should be ok. I haven't touched the secondary carb because I wouldn't think it would be causing problems when I'm only running on the primary carb. I wrapped aluminum tape around the fuel lines this evening in hopes it might help if I have percolation in the fuel lines. I checked the plugs and they all seemed ok.

I just chased a similar deal on a friends 70 Coronet R/T. Ported heads, small cam, stock intake and exhaust manifolds, AVS carb. I could have sworn it was a carb issue, wrong. Ran great then as it got hot it would stall, Pump it and it started right back up. I started checking voltages and found the coil voltage low. Back tracked to the ballast output and it was low. Tested the ballast input and it was low. All the readings were taken while running by back probing. By this time I ran a jumper wire from the battery to the ballast thinking the ignition switch circuit was compromised. The voltage didn't improve but the car continued to run. On my way to the next test the jumper was removed. Removing it caused the car to stall immediately. Several more times the jumper was reconnected and removed, stalled every time. The coil + voltage was still low even with the jumper. The ballast resistance was checked and found in spec at .5 ohm. I replaced the coil with a known good unit thinking the original coil winding's may be shorted causing high amp draw/low voltage. The substitute coil is still on it. Hasn't stalled since.
Doug

could be ignition. Voltage drops as the components get hot. And why anybody would spend all that money on a Hemi and NOT have a set of Holleys on it....
drive it then check the volts at all the usual spots. Good luck that kind of crap makes me want to throw things across the garage.

He said he had dirt in the carbs. Where did the dirt come from? I would be looking at some crap floating in the fuel tank blocking the pickup line.

Had a similar issue on a big loader one time. I know, not an apples to apples, but the result is the same. Crap was floating in the fuel tank and it would run great some times and other times it wouldn't run right at all. Finally had to take the fuel tank off, clean it out and all was well. Just my 2 cents.

Dont you run any filters

filters don't stop everything.

If you have the right filter on it, if it passes threw
it it will pass threw the smallest fuel orifice
EDIT
when we added a charcoal filter we had a issue with
it when it would purge the charcoal filter.. it would
suck in charcoal and plug a air bleed.. we had to put
a filter on it... but this 70 he is playing with didnt
have the charcoal filter

I have a 100 micron sintered Aeromotive pre-filter directly on the inlet side of my Magnafuel 300 pump and it traps small stuff very well and even found cell foam in it yesterday when I checked it after my pump died on me. So far the best filter I`ve ever tried and Magnafuel will replace what`s needed in your pump after the warranty expires for parts only no labor so that`s good news for those of us using em........

The dirt was a black deposit of some sort in 1 side of the carb. My initial thought was the ethanol in the gas was deteriorating the rubber portions of my fuel line so I replaced the fuel filter and the rubber fuel lines but still no good. It has a new fuel tank but I guess it could be dirt plugging the pick up but why does it run fine for a few minutes and then act up? This car has not run right from day 1. When I first got it, it had a slight cruise speed (40-45 mph)miss that I finally solved by disconnecting the vacuum advance. First time I drove the car to a show the brand new fuel pump crapped the bed. Next it was the voltage regulator next the alternator next the power steering pump(twice). I've replaced the coil, ballast resistor, ECU-still misses. It's been totally unreliable!

Make sure the vent isnt plugged up on the tank... just
loosen the cap to check it

Eddy's don't like fuel pressure over about 4 psi according to the local Carb Shop guy. I had a used Edelbrock that I could not stop flooding over , acting just like yours. It turned out it was a worn accelerater pump well which allowed flooding of the carb after about five miles of driving.