Fuel consumption way too high
 

I fired up my rebuilt Merc 454 Gen V -95 (330hp) (std bottom, new machined vortec heads (bigger valves etc) comp~8.5:1, the rest is new out of box: Holley 300-42 intake, comp cam 226 int./236 exh.| 0.544 int./0.547 exh, edelbrock 1410 carb (750cfm)), complete MSD) a couple of days ago.

I broke in the cam at ~2000rpm and ran out of fuel after 10-15minutes :blaster: The bastard had consumed 10 liters in 10-15minutes... The exhaust is now really black from soot/carbon. So the fuel at least makes it through the carb...

The only thing I havent changed is the fuel pump (std belt driven)... I'm going to fire it again today, and take a look at what's happening with the evac.-hose.

But, if the hose is dry - where should I look?! The float levels are ok.


Thanks,

Tomas

Re: Fuel consumption way too high
 

Is there any chance the fuel pressure is too high with a std pump?!

Can the pump of some reason make the pressure too high and push the fuel through the carb?

Re: Fuel consumption way too high
 

2 1/2 gallons in 15 minutes at 2000 rpm's doesn't seem all that excessive to me.Did you ever high idle it like this to break in a cam before?Look down the throat of the carb with it at normal idle now that the cam is broken in,see if fuel is running thru booster venturi's,it really shouldn't be. Make sure fuel isn't burbling out of carb vent from stuck float. take a whif of the exhaust from behind,is it real rich making your eyes water? Smitty

Re: Fuel consumption way too high
 

If I can't find the problem today the plan is to buy a pressure meter on monday. If that is the problem i will mount a pressure regulator.

Re: Fuel consumption way too high
 

A friend of mine with a similar setup used less than 1.5 gallons in 20-25minutes during break in.

I'm going to check the exhaust fumes etc etc when I fire it upp this afternoon. I'm also going to set the timing correctly.

Re: Fuel consumption way too high
 

Sometimes it's almost too easy... I never connected the electric choke...

I fixed the timing and checked everything about the engine tonight, I also made one more cam break in run. It took about one hour and I spent less than 2.5 gallons. :evilb:

Thanks for the support!

Re: Fuel consumption way too high
 

Finished the outside this weekend, now it's almost fit for fight ;) A couple more days then it going in the water...