formula18

Just as the title says i have a 4barrel quadrajet on my 5.7 sbc it was rebuilt last year and has ran great...had some fuel issues this spring and ended up putting on a new fuel pump as well as freeing a stuck float in the carb. I don't know much about these carbs as i just opened it once. the problem i am experiencing now is as follows

1. Hard starting i have to pump the throttle while turning the key in order to get to fire once running it will run above 1500 no problems

2. When i bring it to idle it runs ok for a few seconds at 700-800 then consistantly drops down to about 300 and stalls I am also finding fuel leaking out around the lower gasket between the intake manifold im guessing from pumping the throttle so much

any help would be great guys i will be ordering a rebuild kit online...like i said tips or if anyone else has experienced this problem i would appreciate the help.
-Harry

getrdunn

iTrader: (7)

These are very easy to rebuild. Just take your time. It sounds like you may have more than one issue going on so I would just pull it down and go through everything. What kind of fuel pump did you install. Do you know the fuel pressure at idle? Are you using the 3/16 gasket under the carb? Just wondering if the squish is out of it and your bottoming out on the nylon washer/spacers. It seems like you most defeinately have a float/fuel level issue going on. Those carbs are typically pretty reliable. Fuel filters good, etc.?

formula18

i dont have a guage but the one i istalled is the one for the 5.7 its nothing special just an ordinary pump im not to sure about the gasket thickness under the carb..i have cleaned all the filters tho and changed the separater..thanks for the quick response

getrdunn

iTrader: (7)

Is almost sounds like your not holding any fuel. I assume the choke is working properly or otherwise just remove it if your not sure. I can't remember off hand where the excess fuel goes if the float/needle and seat is failing. I would start looking there. If it's a relatively fresh build you can maybe pull it apart with jeopardizing the gaskets. Pull it apart and start inspecing. If you would like I can send you a good one that you could throw on try out and I can rebuild or figure out your problem and we could exchange or just keep what we have. I have a couple I have no near future use for so it's your call. Just cover the shipping. I just want to see you get back on the water trouble free.

blue thunder

This sounds like a vacuum leak Harry. If you spray some starting fluid around the area where the fuel is leaking and the engine rpm increases, you found the problem.

getrdunn

iTrader: (7)

It does have the characteristics of that also but the only thing I didn't think would make a difference with that is the initial hard starting. Could be though. What happens if you give the throttle a few pumps and then hold it wide open while in the crank position until it starts to fire. Or wont it? We'll get you straight.

blue thunder

Qjets are notorious for hard starting in boats. The bowls are small and leak so it takes some cranking to get them started after they sit. That is why I prefer the holley.

Mufflers are sweet getrdun, thanks. Very happy.

BT

formula18

once again thanks for the replies guys i know they are always hard starting but i could always start it in the idle position once fuel was in the carb. it seems like i have to be mid throttle to get it to fire when starting. i will try some of the things you suggested