Hard Start when engine is warm.

[Ricko1966]

I have a Holley 600 cfm that was rebuilt at a carb shop. The carb is dialed in and adjusted from the carb shop and the choke was pulled off the carb, was told I didnt need it here in this weather.

I just reread this part I doubt this has anything to do with your problem hut still something that needs addressing. Most holleys I've dealt with had a power valve for fuel enrichment. It's one of those things I hate about the one size fits all carburetors. If someone has rebuilt the carbureator to new specs the power valve may very well be wrong for your engine. There is no way that I am aware of to pick a power valve,without using gauge on a running car. Another little nugget of joy is if they plugged the power valve they would have to jet up a bunch. Not the way I'd do it but you probably should ask what powervalve is in it.

 

[BurbanPena]

if you do not have the option to run a return back to your tank install at edelbrock fuel pump its regulated to 6psi and doesn't require a return

 

[Ricko1966]

if you do not have the option to run a return back to your tank install at edelbrock fuel pump its regulated to 6psi and doesn't require a return

The pressure is not the problem its the trapping fuel between the pump and the carbureator. The trapped fuel expands as it heats and blows the needle open

 

[Ajax19]

Sounds like vapor lock electric fuel pump problem solved (carb shop removal of the choke is highly suspect I'm in socal and still use the choke every cold start even on 90° days possible wrong jetting or something else wrong) I run crappy 87 octane with high ethanol content and fires right up cold hot don't matter and without lift pump it would do exactly as described I'm running a Holley facet F.P into the 3line fuel pump no regulator sits around 9psi idle 7psi under load(it's a big block 454 with qjet so 7-9 is perfect) you'll need a smaller pump for your set-up most likely I have the Edelbroken fuel pump on my 53 Buick with a 350 from a vette and runs that just fine couldn't feed a big block though would start and run bad/bog under load when I got my truck it had the wrong lift pump and ran like crap that's why I got it so cheap nothing against Holley but I'd put a qjet back on slap a lift pump and call it done

 

[Ricko1966]

Sounds like vapor lock electric fuel pump problem solved (carb shop removal of the choke is highly suspect I'm in socal and still use the choke every cold start even on 90° days possible wrong jetting or something else wrong) I run crappy 87 octane with high ethanol content and fires right up cold hot don't matter and without lift pump it would do exactly as described I'm running a Holley facet F.P into the 3line fuel pump no regulator sits around 9psi idle 7psi under load(it's a big block 454 with qjet so 7-9 is perfect) you'll need a smaller pump for your set-up most likely I have the Edelbroken fuel pump on my 53 Buick with a 350 from a vette and runs that just fine couldn't feed a big block though would start and run bad/bog under load when I got my truck it had the wrong lift pump and ran like crap that's why I got it so cheap nothing against Holley but I'd put a qjet back on slap a lift pump and call it done

Ajax both of our trucks are plumbed the same way, but I believe there is more to the story than just the electric pump. I originally had mine plumbed through a 2 line pump and my truck was really hard to start hot. The fuel would heat and pressurize in the line, trapped between the check valve in the FP and the needle and seat. As the fuel expanded it would push the needle and seat open overfill the carb and flood. 3 line pump the excess pressure bleeds off to the tank. Problem solved.

 

[Ajax19]

Ajax both of our trucks are plumbed the same way, but I believe there is more to the story than just the electric pump. I originally had mine plumbed through a 2 line pump and my truck was really hard to start hot. The fuel would heat and pressurize in the line, trapped between the check valve in the FP and the needle and seat. As the fuel expanded it would push the needle and seat open overfill the carb and flood. 3 line pump the excess pressure bleeds off to the tank. Problem solved.

That would make sense 3line pump seems to be the way to go I had purchased a regulator with return and ended up not using it been running this pump and setup for 5years now so I know it will work

 

[Ricko1966]

For anyone reading this. My 3 line pump has no pushrod behind it. Im only using it so I can keep my factory steel line to my carbureator, and keep a functional return line. The only reason I went to electric pump is my fuel pump lobe is worn off of my cam. This is only temporary since 2015 but still temporary.

 

[SirRobyn0]

For anyone reading this. My 3 line pump has no pushrod behind it. Im only using it so I can keep my factory steel line to my carbureator, and keep a functional return line. The only reason I went to electric pump is my fuel pump lobe is worn off of my cam. This is only temporary since 2015 but still temporary.

LOL but it is still temporary. Good thinking on keeping the pump like that!

 

[squaredeal91]

For anyone reading this. My 3 line pump has no pushrod behind it. Im only using it so I can keep my factory steel line to my carbureator, and keep a functional return line. The only reason I went to electric pump is my fuel pump lobe is worn off of my cam. This is only temporary since 2015 but still temporary.

I have lots of (semi permanent) temporary things myself lol. Life gets busy.