Hey Folks,
Long time no post because I've simply been driving my car! Now I need some help.
I'm 66 years old, been driving carbureted vehicles all my life and I thought I knew how to properly tune them. It turns out that I'm absolutely and completely wrong! All else seems great, but I cannot eliminate an annoying hiccup/burp/hesitation off of idle and/or light cruise! Here's details of the scenario in my '68 Mustang Coupe:
Scratchin' My Head?
Gene
Long time no post because I've simply been driving my car! Now I need some help.
I'm 66 years old, been driving carbureted vehicles all my life and I thought I knew how to properly tune them. It turns out that I'm absolutely and completely wrong! All else seems great, but I cannot eliminate an annoying hiccup/burp/hesitation off of idle and/or light cruise! Here's details of the scenario in my '68 Mustang Coupe:
> 2000 5.0 crate motor with GT40 "P" heads and stock late '90s Explorer cam, installed 4 degrees (IIRC) advanced, standard 1.6:1 roller rocker arms/T5 transmission/3.80 rear gears
> Edelbrock Performer RPM intake.
> Quick Fuel HR-580VS, vacuum secondaries (Holley 4150-ish, but with 4 corner mixture screws and changeable air bleeds)
> Mallory Magnetic Breakerless, vacuum advance distributor
> Tri-Y headers/2 1/2" Magnaflow exhaust
I have all available accelerator pump cams, a wide selection of air bleeds, idle restrictors, jets, power valves etc. I've played around with many combinations, some were horrendous and a couple others came "close but no ceegar!" Except for this hesitation issue, this 2700 lb coupe is pretty stout and runs fantastic in all other ways. The hesitation/burp, along with having uselessly tried every trick I know, is driving me nuckin' futs!
> Edelbrock Performer RPM intake.
> Quick Fuel HR-580VS, vacuum secondaries (Holley 4150-ish, but with 4 corner mixture screws and changeable air bleeds)
> Mallory Magnetic Breakerless, vacuum advance distributor
> Tri-Y headers/2 1/2" Magnaflow exhaust
Scratchin' My Head?
Gene