ok, so im finished with the carb and distributer swap. ive got everything hooked up and ive started the car. my problem now is the car fires up but doesnt stay running. does anyone have any tips on how i can get the motor to idle so i can start some fine tuning?

-holley 4150 dp
-MSD streetfire HEI

 

Where are your idle screws , transition slots,and floats at ?

 

You will need to crank atleast 10 times to get the fuel pump to fuel the bowls up. I would check your floats if its not staying running.

 

If it is getting fuel (and adequate fuel pressure), I would next look at the initial timing advance. I don't know anything about your motor, but 12* advance should be good enough to get it started and idle.

 

TNT_Z28, did this start out as a carb or TPI car?

What did you do with the computer? With the in-tank electric pump?

I think what may be happening is the in-tank pump is running when you first turn on the ignition, and is then shutting off because it doesn't have a power circuit for the "run" mode.

 

S

 

sorry, ive been really tied up for the last week and havent been able to work on the car. now that im back ill try to answer some of your questions 1st.

1. the car started out as a 1987 LG4 q-jet. last summer i pulled a 350 out of an early 90s 1500 truck. i had the block, crank, heads, and rods completly remachined. i installed a new cam (comp cams xe262 flat tappet) and reused my edelbrock intake and headers from my 305.
Because i ran out of money last summer, i reinstalled the factory HEI distributer and Q-Jet carb on the 350 and reconnected the wire harness. i ran it like that as my daily driver all last fall.
This summer, i decided to upgrade the carb and distributer. i went with a Holley 4150 double pumper 650cfm. and an MSD streetfire for the distributer. i installed these parts and made the neccesary rewiring and thats where im at now.

2. the idle screws are 1 and 1/2 turns out from seat. i havent done anything with the "transition slots, or floats" (im new to holley carbs and carb tuning in general).

3. i have a fuel pressure gauge on the line right before the carb and it reads between 7 - 9 psi when i get it to start and idle breafly.

4. i installed timing tape and used that to set the timing about 12 to 15 degrees advanced from the mark on the harmonic balancer at TDC. i tried to retard the timing slightly after it didnt want to stay running at 12* advanced (it shook that car alot and i had to give it gas inorder for it to stay running.) i dropped the timing a little and it seemed to start an run smoother but shut off eventually.

Also, when i got it to run a few times, it seemed to smoke. (not alot but noticable in my garage) what would this be? keep in mind that i only changed the carb and distrib. since it was in running condition last fall.