so my new 500" low deck runs fantastic, nice crisp throttle response, feels like gobs of power, temp stays at 180 with the HHR fan and alum rad, good oil pressure but I can't even make it to the gas station to fill up because of this weird problem. once the car is fully warmed up and i get about 2-3 blocks away from home the car starts wanting to die when idling in gear, if i throw it in park it recovers and runs perfect and as long as i'm driving it's fine it's just idling in gear at a stop. I put a small pressure gauge at the carb and was running a brand new carter hp pump and the needle would bounce between 11-15 psi till it got hot then sit at 6psi and the clear plastic filter before the carb would start out full then it gets hot and would dry up so i put back my old fuel pump that worked perfect for years, same thing, starts out full then goes almost empty when it gets to operating temp, i can see a small trickle of gas enter the filter but it runs fine in park or neutral. new tank, new pickup, 3/8 steel line (not plugged) all new rubber sections, 2 different fuel pumps, brand new holley ultra hp 950, AAAARRRRGGHHH, i don't know what to do, is the filter supposed to be full of fuel? i would think so or am i missing something, sorry so long, HELP i want to drive

I had a fuel pump push rod drive me crazy for a while,,,it was worn pretty bad,,,,not sure if that would cause the symptoms you describe,,,
Pretty easy to check and see if the length is correct,,and not worn down,,,,

i checked it against a spare that i have when i changed the pump and they are both same length. anyone know if the filter is supposed to stay full to the top or is it okay to see fuel just trickling into it? i know with a metal filter you would never know so it would never come to mind.

Things that come to mind: Fuel is boiling in the carb. Float levels are too low. Tank is not venting. Vacuum leak.

More thoughts. Idle circuit fat/lean, air getting into the fuel circuit,not enough air getting into the carb while driving(choking), old fuel. Good luck, let's see a pic of the engine without the air cleaner on..

I would rule out the pump rod, because if it was warn, it wouldn't change things from hot too cold, I would look into a vapor/venting problem, if it runs/idles good when cold & the filter has alot of fuel in it, but drains when its warm, somethings not right. another thing is, you say the pressure is up to 11-12 when cold, but drops too 6 & holds steady when warm, this shouldn't happen, when it does happens, you need to take off the sight screws on the carb & see if the bowls are low on fuel, if so, then you found the idling problem, if it drops too much in the bowl it'll screw up the metering & idling when become an issue, fuel pressure will drop also if there is air trapped from a bad venting system. Have you tried another guage to rule that out?

Make up a fuel tank that you can hang from the hood
so it gravity feeds... see if it runs on that... then
do a flow test on your pump and tank set up... at least
then you can say weather its a carb or supply issue

but it runs in park or if i'm driving in gear just when i'm stopped, like at a red light and in gear. the weird thing is it runs like this with an empty filter but the gauge reads 4-5 psi steady now that i have my old pump on it. i'll put a link of the new mill running with the other new carter hp pump for gtx dude.

What fuel do you run? What is the Idle in park and in gear? How is your distributor set up... locked or mechanical advance, what is your base timing set @ ?

Possibly a converter issue..



Chris..

By watching the Video, its easy to see that the Bypass is hanging on the electric fuel Pump..
Is this a Holley HP version? They are bad about doing this.

also looks like the fuel pressure is spiking to 12+PSI at times. have you noticed fuel flowing from the boosters at idle? It might be pushing through at idle cause the fuel pressure is highest then, it would be more manageable down the road not to load up..
Fuel pressure shouldn't be much more than 8 PSI...
Either your fuel pump is junk, or its the regulator.. Its shouldn't be dancing around on the gauge like that..

i only put 94 octane pump gas (10.8 to 1), timing is 18 initial and 38 total and i just tried to raise the primary float boal level and turned the needle like 3 turns and the float won't go up. are those black plastic floats any good? it looks like it's just sitting on the bottom of the bowl but fuel is not to the correct level, now i'm just so pissed and confused it should be flooding but i have 4-5 psi. this is a brand new carb that i took apart and cleaned

idle in park is about 950 then about 800-850 in gear until about 15-20 minutes in then park is the same but in gear starts to go down. like i said, it runs like a top until this starts happening. and it's a mech pump with no regulator, the pump in the vid is a new carter street m6903 hp, the one i have on now is the old stock pump i ran for years which sits at about 5psi steady.

You might try to pull the needles and seats and make sure its clean and not blocked

i'm gonna take the carb apart again i guess, got to step away sometimes, i've been wanting to drive the bee with all the new goodies since last fall and it's just one thing after another, just noticed a trans leak now too. thanks for all the suggestions, i'll post what i find (if i find it)

for a pump thats only suppose to generate max of 8psi and now bouncing off 15 might say theres a blockage of some sort causing the pressure to fluxuate like that..have you replaced the fuel filter..in your video the fuel level thru the sites seem just about right..

I had a similar problem with my car...I went to as much as change the power valves, rebuild the carb, replace the filters and then finaly it dawned on me that my fuel pressure gauge is a liquid filled one...I emptied the fluid out and the fuel pressure was actualt stable but I was giving it more and more pressure that was blowing the needles off the seats which made the car die out at stops...

my problem was the gauge..was that checked?


also I use the carter speedway pump where the pressure is 14psi needing a regulator...mine is spot on now at 6psi to the carb...