ready to give up..440 just won't run right.. HELP

[Kern Dog]

If you are running the Mopar Performance electronic distributor......The problem is the air gap.
The air gap is set at .008 with a BRASS feeler guage. If that gap slips and opens up, the car will run fine on light throttle but will sputter and stumble when you lean on it.
I had this very thing happen several years ago and it was embarrassing! I had just tuned the car, added new plugs and was at the dragstrip to see what it could do. It popped, stumbled and sputtered to a 14.83. This is with a car capable of a low 12 second pass.
The Mopar Performance line of distributors have some quality problems. Mine would slip and let the gap open quite often. It also developed a "no-spark" issue on occasion. I blamed everything else...Coil, ballast resistor, the 43 year old wiring too. I ended up pulling it to look inside. The reluctor wheel was clocked wrong because the retaining roll pin had fallen off and fell inside. HOW do you thing that would happen?
All is well with the ignition now. It helped to have spares here to test in the car.

 

[sstocker31]

Check your voltage at the coil and at the distributor with a multi meter for 12v. The stock ignition has a resistor to step down voltage so points didn't burn up. The aftermarket distributors require a full 12v. You could also run a temporary jumper from the battery to test this out.....

 

[Meep-Meep]

If you have Chrysler electronic ignition it seems that the rotor tip is out of phase with the reluctor. Try putting a points distributor in and see how it does. If already running points try a different condenser.

 

[red 69 runner]

Try advancing the timing a couple degrees at a time.I had the same problem with my 383 edelbrock 600 with weiand dual plane manifold auto trans,It would accelerate in 1st and then break down when shifted to 2nd,I advanced the timing a little bit at a time until it went away.This is the best it has ran since the new intake and carb setup was put on last year,had the sputter to and that was from the intake needed to be re torqued,I didnt re check after putting some miles on it and the bolts were loose but I still had the stumble so thats when I started adjusting the timing.I ended up at 17* initial and 36* at 2500.no pinging,I am happy not going to touch it.I have a brand new Holley 670 street avenger sitting in the box that I bought because I was sure it was the eddy carb causing my problem.I just did all this the other day so I may still put the Holley on just because I can never leave well enough alone.

 

[44070dart]

Any chance of a loose connection when you accel it moves enough to cause low or intermittent voltage to ignition? Maybe a loose ground or power wire?[/QUOTE

had to stop what I was doing and come in to fire this off ...GROUND STRAP... can't believe that little ba$tard caused all this aggravation ..took the car out ..jumped on the thruway and ran it up in first then second had to slow down from 90 to get off the exit .. thank you all for jumping in with suggestions.. I'll keep them in mind for future headaches... mine and others ...got to love these sites

 

[snakeoil24]

Remember Ground strap is always overlooked. Power flows from negative not positive.

 

[cwhubb]

I had a similar thing with my jeep yrs ago, ran like a champ at low speeds ran like crap at highway, it turned out to be a frozen distributor, it was defective and wouldn't advance at higher speeds

 

[bigblock]

7-8 psi sounds like a lot of fuel pressure. Prolly not your problem ,just saying. Have you checked the ballancer for true top dead center?

 

[krowbar]

I was having a similar issue with fuel. I had a hesitation when I would throttle the engine at a cruising speed. If I just eased into the throttle it wasn't noticeable. I had to adjust the floats. The front was set way too low.

 

[mikeyfrano]

A lot of good suggestion on what was h as ppening snd I've had most of those happen to me when I was younger. Congrats on the solultion

 

[coloradodave]

I have a brand new Holley 670 street avenger sitting in the box that I bought because I was sure it was the eddy carb causing my problem.I just did all this the other day so I may still put the Holley on just because I can never leave well enough alone.

Isn't that the truth? Couldn't have said it better. Thanks for this look at MYSELF...lol

 

[Garys1969RR]

Wow just a bad or loose ground strap, huh? I have a ground strap running from the rear of my 451 to the electronic ign box. I had read that there is a large amount of current flows to (or from) the box back to the engine. If you think about it, at 6000 RPM that's 100 revolutions a second. Each plug is firing every other revolution which makes 50 sparks per second, Per cylinder. Times 8 cylinders equals 400 sparks per second going thru the coil. And at 10 K to 30 K volts per spark, that's a lot of electricity. And each spark has to ground thru the spark plug ground electrode, to the block, and back to the ign box and coil to complete the circuit. So always run a ground strap from the block to the firewall at the very least. Preferably right to the ign box. Glad you found the problem, 44070 dart.

 

[malex]

Glad that you found the problem. I experienced a weird problem once too. Turned out that the multi tooth timing chain sprocket was off a key. What a hunt that was to find.