View Full Version : Engine sputters
07-22-2000, 03:34 AM
I have an AMC 401 with the Edelbrock perfomer package and 1400 carb. I have rejetted the carb for 6000ft alt. This "new" motor has less than 150 miles on it so far. I have found that after the engine warms up and when I'm at highway speed and give it the gas my engine sputters and surges as if it was not getting enough gas. If I lift off the throttle a little and slowly get back on it, it seems to clear up. It will do it weither it is warm or cool outside. I have the EGR intake but have the EGR vac line disconnected and plugged, this is due to not having a EGR CTO at the moment. The vehicle has just been timed and A/F trimmed by a auto mech. New plugs, points, etc. Any suggestions? Thx
Sergio & Ulrike
1975 Wagoneer "Extreme"
401 AMC w/Edelbrock
07-22-2000, 03:38 PM
Try this, and if it doesn't work, get back to me.
On the linkage side of the carb, at the top of the carb body, there is an arm with several holes, a retaining screw, and an "S"-shaped connecting link to the pump itself. This is the accelerator pump arm. There is a linkage rod fit into one of these holes and retained with a tiny cotter pin.
Since you're coping with altitude, you want to have this adjusted to the quickest response, which means putting the linkage into the hole CLOSEST to the retainer screw -- the innermost hole which will create the quickest reaction for any given throttle change. In contrast, placing the linkage rod into the hole at the end of the arm, farthest away from the retaining screw, will slow accelerator pump reaction time.
Sergio, as mentioned above check the accerator pump curcuit. If that doesn't do it you may have it leaned out too much.
I can't remember offhand if the idle mix screws control air or fuel on an Edelbrock but I think air? Anyway if the mix screws are only out less than one turn from being seated so it runs ok it's generally a sign of too small of a main jet. If the acc pump is working then you may want to go to the next size larger jet.
If the mix screws control fuel and they need to be turned out 3+ turns to run good then it's the same deal, prolly too small a main jet.
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