Idle Problems

[Collin]

I am having a few problems with the 383 at idle. Running the correct Carter AVS with 3 step rods. Checked the fuel pressure today running a constant 3.5 psi. The dwell and the timing is set. The car is hooked up to the AFR gauge in the headers. Under power the car runs at 12 on the AFR gauge. Once it is warm and brought down to idle the AFR gauge slowly (over 30 seconds) leans out to about 20 where it stalls. Under the advice from Edelbrock technician we reamed out the idle circuit. (Before we did this out car wouldn't idle at all). When the car was running at idle we placed our hand over the primaries lightly and the car stalled. We ordered a new intake gasket (thinking there may be a vacuum leak? We did have the intake off and used same gasket but motor had not been fired yet). Just looking to find out why the car won't idle?

 

[quikbird]

What does fuel bowl look like when trying to idle? Afr going to 20 means it is leaning out as it idles. Which is weird. The fuel pressure sounds a little low. I like to see 6-7 psi on mine. There are other more knowledgable people here who should chime in soon, but that is my first thoughts.

 

[Collin]

The manual lists the range at 3.5-5 psi for the fuel pump and carb we are using

 

[cj69RR]

What intake do you have? And what type of fuel are you using?

 

[Collin]

It turned out to be a vacuum leak from the intake manifold/valley pan gasket. Changed it out and it idles and kicks ass

 

[george68hemirr]

cool.......

 

[cj69RR]

Good to hear it's fixed and running strong! Those can be pesky!