[OldCrLvr]

Greetings all. I posted on this issue before( http://www.chevelles.com/forums/showthread.php?t=342930 ) but still have the issue. The engine's specs are on the previous thread. I took Both Aaron's advice from the previous thread. The timing is currently at 20* & seems to be best there. everything on this engine is the same from before except the current cam and lifters.

I am now wondering if there are carb issues (Holley 750 V.S.) because the last 2 times I have started it cold it has done somthing odd. Only on COLD startup it now doesn't fire right up & when it does it loads up on the right bank. At this point there is fuel coming out past the air cleaner housing onto the exterior of the carb. When looking down carb after innitial startup I see no fuel coming out or overflowing from the vent's.

I have taken a couple videos from inside. The one in the daytime doesn't show the hesitation as well and the one at night is harder to see the tach because I was a retard.
http://s761.photobucket.com/albums/xx253/oldcrlvr/?action=view&current=VID_20110424_194947.mp4

http://s761.photobucket.com/albums/xx253/oldcrlvr/?action=view&current=VID_20110213_205151.mp4

Even if I am at a cruising or freeway speed the hesitation is still there.

ANY help would be GREATLY appreciated!
Chris

 

[Dave427]

It can be a few different things on your carb.
Are you comfortable about putting a kit in it?
I would put it back to stock jetting etc.
If so it could be the power valve a bit on the lazy side.
It could be the 4 barrel vacuum diaphram check ball missing allowing the 4 barrel to flop open.

Dave

 

[Camaro_fever68]

If timing is in check, move on to the squirters on the carb. Looks like you need a more aggressive squirter cam and/or a larger squirter nozzle. My suggestion is to get a 35 squirter and blue pump cam (Holley #427). Set the cam up on the #2 position and make sure their is no slack in the pump lever when at rest, but at least .010" at WOT.

 

[OldCrLvr]

It can be a few different things on your carb.
Are you comfortable about putting a kit in it?
I would put it back to stock jetting etc.
If so it could be the power valve a bit on the lazy side.
It could be the 4 barrel vacuum diaphram check ball missing allowing the 4 barrel to flop open.

Dave

I have no problem putting a kit in it. This carb was unuseable when it was on a 56 chevy I used to have. I last rebuild was about 10 years ago. I know it does have the check ball in and the carb has not been tampered with. As mentioned before all is the same from before the cam swap. Hell, when I pulled the intake for the swap I didnt pull the carb from it. I have a big box of jets so that is easy enough to do. I don't recall what is in there now. How would I know if the power valve is lazy? By the way there is no power valve protection on this carb. I don't mind tweaking things but would prefer to trouble shoot everything first. Money is tight and I am also trying to get our Nova ready for the cruise in season.

 

[Dave427]

If it hasn't been kitted for 10 years thats where i would start.
If its a 3310 the stock jets in the front are 72's and it uses a plate in the rear.
The Holley kit is a 37-1542 and like mention above it wouldn't hurt to increase the squirter size as well.

Dave

 

[OldCrLvr]

If timing is in check, move on to the squirters on the carb. Looks like you need a more aggressive squirter cam and/or a larger squirter nozzle. My suggestion is to get a 35 squirter and blue pump cam (Holley #427). Set the cam up on the #2 position and make sure their is no slack in the pump lever when at rest, but at least .010" at WOT. QUOTE]

Truth be told the most tinkering I've ever done with a carb is jetting and setting the idle mixture screws. I do have some cams in my carb parts tray but I don't believe a blue one. There is an orange one on it now. I do definatly fit under the blue catagory per the Holley video you provided. I'll put it high up on the priority list. I'm not sure about the nozzles. I assume they have the number or some sort of designation on them? Is ther any literature out there advising on how to choose a squirter nozzle?

 

[OldCrLvr]

If it hasn't been kitted for 10 years thats where i would start.
If its a 3310 the stock jets in the front are 72's and it uses a plate in the rear.
The Holley kit is a 37-1542 and like mention above it wouldn't hurt to increase the squirter size as well.

Dave

Dave, Thank you for your advice. Ive bench raced with some co-workers and all keep telling me its timing. If I had another carb to swap I would have to see if the prob persists. I think what I'm going to do is tinker with the cam and or squirter first and then as time and money are available I will put a kit in it. Unfortunatly my fairly new Griffin radiator has sprung a leak so I can't drive it too far at this point. :sad:

 

[superstocker72]

i would keep going up 2 squirter sizes until the hesitation goes away, after you rebuild it of course

 

[OldCrLvr]

I just checked my squirter, its a #25.

When I looked through my carb parts and pieces I found a #21 which is in the wrong direction. I also found a whitish cam on a 600 which im assuming is pretty tame. I came home thinking I would look at summit's web page and print out the info/price of a blue cam to have the O'Reilly's match it. Apparently I need to purchase a kit to get the blue one. Seems they don't sell too many of them as singles.

I have a coworker who has lots of Holley parts/pieces/kits, I think I'll ask him if he has any I can play with.

 

[superstocker72]

a 25 is way too small i think a 31 would be a good start

 

[Camaro_fever68]

I just checked my squirter, its a #25.

When I looked through my carb parts and pieces I found a #21 which is in the wrong direction. I also found a whitish cam on a 600 which im assuming is pretty tame. I came home thinking I would look at summit's web page and print out the info/price of a blue cam to have the O'Reilly's match it. Apparently I need to purchase a kit to get the blue one. Seems they don't sell too many of them as singles.

I have a coworker who has lots of Holley parts/pieces/kits, I think I'll ask him if he has any I can play with.

The blue cam is available on ebay by itself. After shipping and whatever, not sure if the kit isn't a better deal. I buy them by the dozens from AED carbs. About the only cams I use in my tuning bus.

You can go up two sizes at a time on squirters until you're blue in the face. If the cam profile isn't right, squirter size seems to make little difference. Just remember... Cam profile dictates when the fuel comes out, squirter size dictates for how long.

 

[OldCrLvr]

I figured I would give a small update. I haven't had much time at home but did do a couple things which seemed to help considerably. First I adjusted the linkage for the acc pump. I also pulled the primary fuel bowl, set the float height and put in the factory jets. I had moved from the 72's to 68's with the previous setup. I only took it on a short test drive but the hesitation seems to be gone. It is however not as responsive as I feel it should be.

 

[MEJ1990TM]

Like Ben said, the 31's would be a good size squirter to try. That is what size is on the 3310 on the '70.

 

[OldCrLvr]

Like Ben said, the 31's would be a good size squirter to try. That is what size is on the 3310 on the '70.

I will try that next. I was able to get a bunch of squirters as well as cams from my coworker.:thumbsup: Unfortunately the only blue cam he has is on his Chevelle.