Swiching from a smog to a performance engine.

Badasspen

Badasspen

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I installed a performance motor in my 76 Aspen RT and am having some stumble and stall issues. At high RPM it is barely noticeable but the car will stall at a stop sign or light, but start right up again with no trouble. When cold starting sometimes it starts right up and other times it seems to be only running on four cylenders and then stalls. It is obviously an ignition issue, i have a few wires left open from EGR, smog pump, and whatnot and was wondering if the ignition may be grounding out on the motor or chassis causing this. I have a 5 pin black box electronic ignition installed but have a 4 pin chrome box on the shelf. Any suggestions?
 
Badasspen said:
I installed a performance motor in my 76 Aspen RT and am having some stumble and stall issues. At high RPM it is barely noticeable but the car will stall at a stop sign or light, but start right up again with no trouble. When cold starting sometimes it starts right up and other times it seems to be only running on four cylenders and then stalls. It is obviously an ignition issue, i have a few wires left open from EGR, smog pump, and whatnot and was wondering if the ignition may be grounding out on the motor or chassis causing this. I have a 5 pin black box electronic ignition installed but have a 4 pin chrome box on the shelf. Any suggestions?
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Try the other box...if my memory serves me right it is only using three wires anyway...one should be ignition on...one should be 12 vdc and one should go to the coil
 
stutter and stall

Changed the box, works but no help. Found out the vac. advance does'nt work. Could be a problem ya think? Got a new on on the way.

:oops:
 
Changed the box, dist, cap, rotor, still has a stumble at wot checking for vacuum leaks not . The good news it don't stall anymore.
 
Badasspen said:
Changed the box, dist, cap, rotor, still has a stumble at wot checking for vacuum leaks not . The good news it don't stall anymore.
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That could be a carb issue...put vacuum guage on manifold full vacuum...if your vacuum advance died before it could have been a prior source for a vacuum leak
 
The performance orange and Chrome box's use 4 wires, the Gold box 5 wires, not wired the same as the stock 5 wire box.
 
I was wrong before when I said three wires...in our cars they used five wires who would of figured..

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The vacuum advance diaphraghm was damaged causing a vacuum leak. Gave it the oral suck test. First time I ever saw that. Runs much better now that I got a new stock unit from NAPA. Kept the chrome box, well see what happens next.
 
A MoPar Chrome box? It's a good unit.
Don't run the Gold box on the street. Not for long anyways.
If you have a standard chrome box, it's a stock replacement box that is a little better and highly recomended for driver use. It is a better quality box for driving.
 
I did a Lean Burn delete on my other daily driver with NO mopar parts... was half the cost of the Mopar box... If interested let me know and will do a write up on it. Actually yes mopar parts were involved, an electronic vac dist, and earlier model Thermo-Quad carb...
 
Sorry it has been so long... life happened, but as soon as it warms a bit I will get the write up done... I need to tidy up the wiring on car also for pics...
 
Thanks for the update. Look forward to more. What engine did you put in it?
 
Eastyorker said:
Thanks for the update. Look forward to more. What engine did you put in it?
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It wasnt an engine swap, it was on my '77 Newport with the 440 lean burn... Lean Burn system was crap, was getting MAYBE 3mpg. After the change over it has improved to 14ish in town, with easier starts.
 
after typing it all up, its a pretty lengthy item, (even tho some of it was just a back story to the car) I can still post if anyone is interested...
 
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