First, the backstory: Six years ago I bought a new Edelbrock 1403 off of Ebay. A few months later, after getting a spiffy Jeff Rice converted intake manifold, I made the swap...only to discover that the carb I bought was NOT a 1403 but a 1406. Stupid on my part and then too late to return it. So, I bought a new 1403 from Summit. Put it on the car and it ran great. The 1406 went back in the carton and on the shelf. When I decided to pull the old motor in favor of a rebuilt full-flow, the 1403 was pulled and sat covered up on the shelf for some two years.
Fast forward to now: Finally get the new motor and tranny installed, put on the 1403 and started up the motor. Could not get it to run smooth, could not get it timed...thought my problem was ignition related. Hmm, maybe the 1403 was gunked up/dried out, etc... so, I swapped it with the 1406 that had been sitting there and, by golly, the car ran great (after setting the timing, idele mixture, etc.).
So, knowing that the 1403 is a better match for the stock 289, I took it in to "The Carburetor Shop", a well-known carb specialist in St. Paul and had them go through it (to the tune of $170).
Got back home, took off the 1406 and put on the 1403. Car ran like crap. Was getting too much fuel and only one of the idle air mixture screws would effect any change.
So, put the 1406 back on...car runs super. Returned to The Carburetor Shop with the 1403. Explained what was going on and he gives me one of his 1403s that he said he'd completely rebuilt.
Got home, put it on...car runs like crap...same as before but now none of the idle mixture screws effect any change. Fuel going into the motor like its the dad-blamed Alaskan Pipeline (okay, a little embellishment there). Tapping on the carb was ineffective. This morning I put the 1406 back on...runs as it should.
Questions: Am I missing something here? Is there some critical difference between the 1403 and 1406 that would cause this? Am I just the unluckiest carburetor buyer of all time?
Appreciate any thoughts on this.
Fast forward to now: Finally get the new motor and tranny installed, put on the 1403 and started up the motor. Could not get it to run smooth, could not get it timed...thought my problem was ignition related. Hmm, maybe the 1403 was gunked up/dried out, etc... so, I swapped it with the 1406 that had been sitting there and, by golly, the car ran great (after setting the timing, idele mixture, etc.).
So, knowing that the 1403 is a better match for the stock 289, I took it in to "The Carburetor Shop", a well-known carb specialist in St. Paul and had them go through it (to the tune of $170).
Got back home, took off the 1406 and put on the 1403. Car ran like crap. Was getting too much fuel and only one of the idle air mixture screws would effect any change.
So, put the 1406 back on...car runs super. Returned to The Carburetor Shop with the 1403. Explained what was going on and he gives me one of his 1403s that he said he'd completely rebuilt.
Got home, put it on...car runs like crap...same as before but now none of the idle mixture screws effect any change. Fuel going into the motor like its the dad-blamed Alaskan Pipeline (okay, a little embellishment there). Tapping on the carb was ineffective. This morning I put the 1406 back on...runs as it should.
Questions: Am I missing something here? Is there some critical difference between the 1403 and 1406 that would cause this? Am I just the unluckiest carburetor buyer of all time?
Appreciate any thoughts on this.
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