engine quandry

[roechambeau]

while test driving fresh 350 rebuild engine died on me after coming to a quick stop at the bottom of a hill. weird thing was it wouldn't start unless i was furiously pumping the gas and then would only stay running over 1800 rpm or so. anything less and dies. did this for the next 3 miles al the way home. so i get out and take a look under the hood and the gas is slowly draining out of the clear fuel filter back down into the pump. shouldn't the gas stay in the filter for the most part or have i just never noticed it b4. curious if vapor lock would cause this? holley is sitting on a 2 inch alum spacer. i would have thought that should hinder vapor lock for the most part. any ideas???

 

[Mad-Dog]

Aluminum is a great conductor of heat (not a insulator), maybe u want a composite spacer instead.

The float could be stuck causing a flooded condition and the fuel pump may have a bad check valve.

 

[trailblazer86]

At one time I had a Quadrajet sitting on a medium rise aluminum intake.(327cid that ran 3600rpm at 65 mph)
It would act the same way at certain temperatures.
The problem wasn't heat, it was cold.
If your spacer is the open type it is pretty huge for an engine trying to run below 2000 rpm.
Open plenum is meant for high revs.
This will have a big effect on drivability.
Now if you have the four hole type this may help feed your engine at mid range rpm’s.
My fuel filer drains also. (also an 86)

 

[roechambeau]

i will have to go look for a phenolic spacer. i run a 4 hole spacer. but i wasn't sure if fuel pumps have a check valve or not. seems like they should but the way mine was draining off it didn't look there was one. i thought the fuel stayed in the line....i will have to check the floats. the carb has been sitting for a few months.

 

[LongIslander26]

Dying engine

Be sure your idle set screws are set properly too. Normally you turn them all the way in, than back out 1 1/2 turns, and that'll get you started to fine tune them from there.

 

[unclematty]

Be sure your idle set screws are set properly too. Normally you turn them all the way in, than back out 1 1/2 turns, and that'll get you started to fine tune them from there.

I think you mean the Air-fuel mixture screws. Front of the quadratoilet, underneath the bowl??