Got the carburetor swapped out to a 750 and the carb shop called me and said they swapped the metering rods 4 sizes and it's running good but the O2 gases are 3 times higher than normal. Is this normal for this setup 401 with a edelbrock 750 or is the carb bad
Which Edelbork 750? There's an emissions calibrated one that's leaner. There's probably several possible explanations for their readings. O2 readings are not always the best way to tune things in, but I'll assume that they know what they are doing.
It would be extremely difficult to answer your question better than the people who have the vehicle at their facility based on your information, sorry.
I think I read somewhere that one of the reasons the Carter AFB stopped being used in OEM applications was that it wasn't emissions friendly. Not that it matters in a performance application. I'm sure most if not all out of the box Holley DP carbs would run pretty rich everywhere. What exactly are the readings and when are they measuring them, idle, cruise, WOT? Can you find out what rods they swapped in? Just changing metering rods may not be enough to get where you want to be. BTW, where is that? Here is the Jegs page on the 1407 and base specs, http://www.jegs.com/i/Edelbrock/350...nel=Shopping&gclid=CKbFy7CJuNICFRGHswodj40Llw
1407 already has a richer cruise rod. no way do you need to go up 4 more sizes on the cruise mod. but most of all they only make a metering rod 2 sizes bigger for wide open throttle, from 47 to 37.
I actually think it's a 1407 I have on my 401".. Right out the box, my spark plugs are very nice light brown, and the car runs with no bugs anywhere ( idle-wot ) I live at sea level..
same here. but i went smaller at cruise with no surge. something is not right to go up that big even with ethanol fuel.
I don't have a ton of experience with the 1407 but I do have the more economical 1411 on my 425. I installed it and it fired up first crank and has been running amazing with no out of the box changes. No surging, no hesitation, and no misfiring at any throttle position. I live at sea level. You can look up the specs on both carbs on the edelbrock sight and there isn't that much variance in metering rods and what not. How did the shop come up with "3 times higher than normal"? What is/was the baseline? What kind of carb did you replace? Chris
Just deleted a big rant Let the shop sort it out, they are using test equipment that shows whats going on, they know whats happening. Go there and tell them how to do their job and see how long your car stays in their workshop
Agreed. Additionally, the shop should be able to CLEARLY explain why they are seeing the situation at hand and offer a reasonable solution.
