I have a mustang with 289 just dropped a 4 barrel 600cfm Edelbrock
preformer carb in it, after shutting it off the engine diesels. I pulled
off the air cleaner and found out that when the engine turns off gas sprays
"Dieseling" or after run can be caused by numerous things.
Among them are idle speed too high, mixture too lean, timing
retarded, engine temperature too high, fuel octane too low
for engine or wrong heat range plugs installed. If you have
had the heads rebuilt, the valves may be too thin or the
compression too high which can be caused by carbon buildup
in the cylinders or build specs. It is normal to have some
back spray when this occurs as the ingnition is not
controlled in any way resulting in pressure in the intake.
The back spray is not of itself an indication of a carb
problem. It has been my experience that the Edelbrock and
other derivatives of the old Carter AFB design tend to run a
bit leaner than other designs and must be properly
calibrated. Overall, IMHO, this is a more efficient design
for a daily driver vehicle with better reliability than some
others and tends to "stay in tune" better once you get it
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.