My car boggs down when i start from and stop it to the floor the engine stalls for a second and then it takes off. if i slowly press the gas in the car does fine
the car was a cross-fire car now i have a 327 with a 600 double pumper
i think the pump in the tank is causing it carb not to get all the fuel it needs

Help Please

 

my car does the same thing except its just 305 with the qjet. i was told by a couple people that it could be a vacuum leak. i've found 5 leaks and it still does this. so i would also like some more info on this.

 

osbornepe, welcome aboard thirdgen.org.

GTAwheelman, it might sound like the same problem, but it's for completely different reasons because the Holley and q-jet operate in completely different manners.

So, osbornepe, I can tell you right now it's not your fuel pump. The carb operates off of fuel available in the fuel bowls, and all the pump does is refill those bowls. Step 1 is to verify the float levels are proper in the carb - the fuel should be just dribbling out of the site plugs at idle. Step 2 is to verify your ignition is up to snuff - the old saying goes that 75% of carb problems are fixed by tuning up the ignition. After those things are verified proper, look at your accelerator pump circuits - a mis-adjusted or improperly operating accelerator pump will leave you high & dry.

GTAwheelman, you need to read the tech article about getting the most out of your q-jet (linked from the thirdgen.org homepage, or the welcome to the carb forum sticky above). A leaking choke pull-off is a good way to have a problem, while maladjusted AV tension is another.

 

i have a msd6al good set of plugs and a Mallory Magnetic Breakerless Distributors

 

And timing set at. . . ?

 

will do, thanks

 

4 dec of timming

 

8-12 initial, at idle, with vacuum disconnected, would be more like it.

 

the Distributor does not have a vacuum on it

 

You really should set the timing for total mechanical, 34-36 is typically what non-Vortec SBC's like. Let the initial be what it is (assuming your mechanical advance isn't totally anemic - do you have the bushings and springs for the distributor?).

Why aren't you using vacuum advance? Is this a track-only car? Wild cam?

 

here is a list of what i have a 64 327 with flat top pistons the cam is 2600 to 6200 290/290 223/223 duration @.050 left .446.446 centerline 107/117 lobe separation 112 heads summit vortec heads
67cc Combustion Chamber part # SUM-151124
1.6 roller rockers
Mallory Magnetic Breakerless Distributors part # MAA-5048201
8.5 mm wires
msd 6al with a 6800 chip
Vacuum Reservoirs
700r4 transmission with a lock up
2800 stall
alm drive shaft
7.62 locker with 3.42 gears
i think it all goes together good
if i have something what does not work well with this please let me know and i will do my best to change it

 

i got the distributor from summit it was only a couple dollars more than the Unilite so i got it. the car is a street car

 

Sounds like an insufficient pump shot.

What accelerator pump cams and squirter nozzles are you using?

 

It might be an insufficient pump shot, but until the ignition timing is where it should be, you can't know that.

You should have gotten a vacuum advance distributor for street use.

 

I agree about the need to check the ignition timing, I was just suggesting something else to look at.

8 degrees of intial timing should be a good starting point, the Mallory distributors I have worked with in the past came with 24 degrees of mechanical advance out of the box. Watch/listen for detonation, with flat-top pistons and vortec heads your engine shouldn't need much more than 32 degrees of total advance.

If you find that your engine likes more initial advance but you are running too much total advance, you may need to go inside the distributor. I'm not familiar with the advance setup on that particular distributor, but it should be possible to limit the total mechanical advance and run more initial timing.

As suggested, try bumping the initial timing up and post back with your results.

 

32 prime and 28 second squirtes power valve bocked off
holley 600 double pumper
holley 600 vac 2nd has been on car worse with this one

 

8 to 12 helped a little it does not as long as a delay but it still a delay

 

Why the bigger squirter on the primaries than the secondaries?

Nothing to do with the bog, but you really should have vacuum advance and at least a primary power valve for a street car.

 

Did you buy the douple pumper new or used? If you bought it used, I would recommended that you ensure everything is at factory settings before you try and trouble-shoot the carb.

Do you have a list number for your 600 double pumper? Should be stamped on the choke tower. We can tell you what jets/pv's/squirters/ came originally came with the carb.

 

i got the it used the list # is 4776-5 d690

 

http://www.holley.com/data/TechServi...%20Listing.pdf
Page 3 & 4

Primary jets 66, secondary jets 73. Power valve 6.5. Primary squirter .028, secondary .032.

 

According to my Holley book, that carb has the following stock configuration:

#66 jets and a #28 squirter nozzle on the primaries. 6.5 powervalve.

#73 jets #32 squirter nozzle on the secondaries. No powervalve.


What color are the plastic acclerator pump cams that are currently on the carb?

 

stock plastic acclerator pump cam

 

The color of the plastic indicates what type of cam it is. Are yours red?

 

yes it is an off red