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...

Pull the gas cap off and see if it changes

you know what woody, i'm tending to think a blockage also, maybe in the primary bowl since i just noticed the float laying down in the bowl and no reaction from trying to raise it. mr. P i already tried that but definitely good call, thanks

The gauge you are using is not one of those liquad filled ones is it??? Those are the must inaccuarte. As the oil in the gauge changes tempertures you get different readings.

If the fuel level is high and the float is sunk it is either bent or full of fuel. Black ones don't fuel log that I have seen. Once the needle and seat is adjusted too much it does not close any more. Kinda goes past center. You may need a fuel regulator.
Black ones are bad for the tang bending! But it can be bent back up and start over.

I like to hold bowl upside down and adjust till float is centered kind duplicates the fuel floating it!

If you bought a liquid filled fuel gauge toss it!!

ok, i'm a little embarrassed and still a bit confused. it is a new carb and it seems it was the float level causing it to die in gear idling (oops, feel like a bit of a dummie), i took the floats out and indeed they needed to have the tang bent back on them so i could get a good fuel level in the bowl (thanks dodgem, good call). so the car runs ok now BUT....the filter still starts out full and after 15-20 minutes is almost empty with just a trickle of fuel in the inlet, the car runs good and the gauge reads 4-5 psi constant, it just has no fuel in the filter????? should i just consider this normal? thanks to everyone for the help, i just wanted to share what i found but if anyone can explain if the empty filter thing is normal or not i would love to hear your thoughts, again it's an old mechanical pump on it now with no regulator.

curious about the empty filter thing?

take the filter out and try it . I would run larger fuel line and atleast a real 3/8 or larger filter .The fuel gauge it's self could be a resriction .
keep us posted
DR

If you use a longer hose and point the filter out down it will fill. Then you can sleep at night.

Check for restriction on the tank vent. Sounds like some, not complete vapour lock. I had this on the Ramcharger I bought. The filter was always empty after changing a new stock 360 fuel pump I noticed the joker removed the charcoal cannister and plugged the vent line with a bolt. Clear filter then filled up once I cleared the vent line. There is some slight air in the top as some mentioned. My big block coronet with carter super pump, the filter fills right up after a couple seconds.

Two reason I know of for seeing air in that filter.

Heat-Gas is boiling in the line causing air to accumulate in the filter.

Other is pressure surges from the needle and seat. This is kinda complex. Never really seen this first hand. But, was told by a veteran Comp racer that when the needle drops allowing fuel into the bowl every thing is great. Then is slams shut causing a reversion in pressure. If it opens again soon enough after closing and catches that reversion supposedly you can actually get air into the fuel line.

The last one I have never actually watched and personally seen happen. I understand some of what is being said because I have seen a similar situation in an intake manifold with parts coming apart in one cylinder ending up all through the intake manifold and into other cylinders.

If the air in the filter really bothered me and I had already tried standing the filter up first. You could try a fuel return system. I think Magnaflow makes an adapeter that goes between the hose and the fuel bowl. This adapter allows you to hook a very small line up that returns air and fuel back to the tank. It is a lot of trouble to do for a street car and would probably be something that you would have to homemake considering the plumbing you are using.

Leon

I would think you will be better off with the filter down low, out of the engine compartment heat. Maybe a good phenolic spacer to help the carb too. But before you quit and feel it is all fixed, it would be a good idea to check the entire system, starting with a flow test of the pump, then move up the line all the way to the carb one piece at a time.
that way, when the summer heat comes, you will be ready!