• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Edelbrock carb question

Sonny

It’s all fun til the rabbit gets the gun.
Local time
3:20 AM
Joined
Jan 19, 2017
Messages
1,300
Reaction score
403
Location
Florida
I have a new Edelbrock avs2 carb on a rpm air gap intake on my ‘78 360. Here is the problem (I believe). My idle vacuum is a strong 21”. When I go from cruise mode to cruise acceleration, my air fuel gauge goes lean and not richer. I am using the stiffest step up spring, but I think it can’t overcome the high engine vacuum and raise the metering rod. Anyone else have this problem?
 
I'm not a carb expert, but I had a good conversation with someone on the FABO (ForABodiesOnly) sight. From what he was saying, what you are seeing is normal. I will attach a snippet of our conversation on here for you. I will also post a link to my thread over on FABO. The part we were discussing this information is on the last page (specifically Post#53)

He said,....
"The clue [relationship] here is rich idle, lean cruise, leaner (leanest, actually) part-throttle acceleration and rich WOT. The leanest is at mid-load, half-throttle or so.

http://www.forabodiesonly.com/mopar...g-to-compare-to.395945/page-3#post-1971912549
 
Smaller diameter rods is probably what you need. Your 21” vacuum will surely drop on any kind of acceleration.
 
Smaller diameter rods is probably what you need. Your 21” vacuum will surely drop on any kind of acceleration.
I’m using a 7537 with a .104 primary jet. Cruise afr is already rich at 11. If I go smaller than 75, cruise will be more rich. Plus 37 is the smallest tip too. I feel like I’m trapped between the two ends.
 
858FFD0C-358C-4989-9BFF-AB89498F46B1.jpeg
Would this air cleaner be restrictive enough to cause a rich cruise?
 
Probably not, maybe ur going at this wrong; what are the timing specs? Idle,2000rpm, over 3000?
 
Probably not, maybe ur going at this wrong; what are the timing specs? Idle,2000rpm, over 3000?
Terrible ha ha! I’m putting in a new Mopar electronic ignition conversion kit in it tonight. I’ll let you know tomorrow with the new system what the timing specs are.
 
#1 Rule in tuning is to get the timing squared away BEFORE trying to tune the carburetion. Otherwise you'll be chasing your tail for a long time...
 
Probably not, maybe ur going at this wrong; what are the timing specs? Idle,2000rpm, over 3000?
Ok. Got the mopar electric ignition conversion installed and is working nicely! It said to start with 5 deg initial timing...when I rev it to about 2500 it’s at 25 deg. I haven’t hooked up the vac adv yet. It actually idles nice and the pedal is quite responsive at 5. I expected sluggishness but not so. Anyway, should I use 15 initial to get to 35 total, or let the vac advance do it? Or leave it where it is? By the way, I swapped the snorke air cleaner with an open type and my cruise air fuel ratio went from 11 to 12.5 (on the highway at 75mph) no change around town though- guess the new dizzy and timing could have changed it some too
3399D549-EE79-44DF-B659-88808B8775FB.jpeg
 
I would suggest setting initial to 15-17 to get 35-37 total advance. It will start better and have more snap.
I think 12.5 AFR is still rich for cruise 13.8 - 14.2 is what I like. Try a smaller primary jet and see how it acts.
 
Sonny;

Did the ignition kit come with instructions?
Do you have the MP engines book?
Do you have the Edelbrock instructional booklet on “How to tune your Edelbrock carb” by chance?
 
I have the Edelbrock tuning book; however I spoke to their tech support complaining that they haven’t released the tuning charts for the AVS 2 yet. Should be next week they said. We’ll see.
 
You shouldn’t need the new tuning touch. The old way and will suffice just perfect. There is no newfangled way to tune a carburetor.
Please do remember that carburetors about earthquake me to refuel. It is designed to constantly confused and compound the end-user. With an Edelbrock, Jet it, set it, forget about.

Carburetors stay tuned only on the day they were tune on.
Tomorrow, there out of tune.
 
Auto Transport Service
Back
Top