I have a Holley 670 avenger. It's been ok since I installed it. Over the past couple of months this is what has been happening. At an Idle my A/F is around 12.8. It's always been set that way. Now after a couple min it goes 12.8 - 12-7 - 12-6 - 12.5 ect..... all the way down when it gets to 10.8 it stars running rough until I tap the gas and get it back to 12.8... What would cause it to start running rich at idle? My fuel pressure is set right at 6-7psi steady ( I have a gauge in the car ).....

Thanks

A leaking needle and seat will cause it to go rich at idle.

A leaking needle and seat will cause it to go rich at idle.


Called Holley today. They told me if the carb has a # 5 or 6 after the last 4 digits under the model number to send it back and they will give me a brand new one. I read this on another forum. This could be why.....

http://www.pirate4x4.com/forum/showthread.php?t=707532

He said any 670 avenger not just the truck. Mine ends in 6.

Did you decide to keep the twin turbo's??

Did you decide to keep the twin turbo's??

Yup! Just got off the phone with Alan from Extreme Performance Coatings. I sent my headers and 90*'s to get coated. The turbo housings are getting polished also.

I'm going to run this motor for a while so I might as well get it fixed. I sent it out today and they are sending me a new carb.

New Holley is on the way. Guys check your #s and see if yours is defective too.

Got the carb back. Idles and runs 100% better. No more stumble that I was trying to fix for the last year and a half. A/F is now 13.9 instead of 12. Very happy.:D Have yours checked out guys.