I also changed the fuel filter. I have an in line fuel filter that is clear. I noticed when the truck is running it never fills with gas any more. Only fills about a 1/3rd of the way could I be losing my fuel pump?

 

fuel pump or just screen in tank may be plugged.

cheers.

p.s. the next time your holley goes to hell, throw it away and buy an edel or carter or something worth owning.

 

Thats comedy. Holleys never go to hell they ust get ruined by guys that cant tune!


For the OP, you have an Idle air bleed problem. Look down the choke horn, and notice some small holes around the front edge. These small orifices are responsible for the idle circuit. SO make sure that the throttle blades are not open too far. This is common with Holley carbs, and once you are sure that the transition slot is exposed properly, and your idle moxture screws are close, you should start to dial it in. You will never get there, if these idle air bleeds are contaminated. Dirty air filters, and K&N filters that recieve too much oil can cause this symptom. Just so happens that the small plastic tube that comes with a can of carb cleaner fits in these small holes. More advanced carbs actually have adjustable idle air bleeds and emmulsions, but for yours, you just have to make sure that they are clean.
Dont sitch your current carb, and dont throw another problem carb on there. Learn to tune yours, and you will be satisfied.
The Holley is probably the most misunderstood carb out there. Folks think there is some "magic" involved with them, but understanding this design can help you with impressive power, and great driveability. Really.

 

Suggestion: Edelbrock. lol

 

I can't wait to get to the point where I can learn about carb adjustments. I'm a long way away. I'm learning about body repair and rust fixes.

 

Check to see if your choke is opening all the way when it warms up... sounds like its flooding itself out kinda... does it smell rich when it runs?

 

I checked the plugs and they are perfect. So I dont think it is rich.

 

If you throw a holley away and go to an edelbrock you are nuts. Holley's are much better carbs than edelbrock. Listen to 75F350 and get it cleaned and tuned right and you will be happy.

 

For Carb idiots like me I just read through HPBooks Holly Carburetors, By Mike Urich & Bill Fisher.

 

Rep to you!

 

Throw away a Holley? Holleys are easyer to tune than an Edelbrock if you understand them IMO.
Although if you do want to throw away them no good Holleys, I will gladly take them off of you hands anytime .

 

So you dont think it could be the fuel pump?

 

I do not feel that the pump is the problem here because this issue is only an idle issue. You stated that the engine runs fine, and the higher rpm the greater the fuel demand. This eliminates the fuel pump.
Have you verified 100% that you dont have a vacuum leak? Verify the vacuum modulator for the trans, as well as brake booster and PCV. Tricky little things like that can go overlooked.

 

Best way to check fo vac, leak is with carb cleaner right?

 

I use propane myself, but carb cleaner works. You just have to be very carefull around the dizzy. Car cleaner is a volitile liquid and will catch on fire if you spray the dizzy cap. Real enlightening experience. Eyebrows take a while to grow back.

Did you check the little air ports inside of the choke horn?
While you are checking for leaks, also check the throttle shaft for leaks. Check right where it pivots inside of the base plate. Move the throttle shaft up and down with your hand while you check for leaks. The throttle shafts have a bushing that will wear down and can leak when some tension is applied dto the linkage. Just be precise and you will find your problem. It is a little problem, and the solution is simple. I am sure of it.