please help....quadrajet shoots a fountain of fuel.

[01maroonz71]

well, we just put a new fuel pump on an 84 jimmy and we also had the quadrajet rebuild. now, it starts to sound like it's gonna fire up but with air cleaner off, it blew a shot of fuel up out of the carb. right out of the little thing that sticks up out of the front of the carb. i think it's called the pump assembly, but i don't know. it looks like a vac hose would fit on it(brake booster size) but im not sure what it's for or what it does. anybody have any clues???? could the carb be assembled wrong????

 

[ryoken]

That's the bowl vent... your float or needle/seat is stuck, installed incorrectly, etc...

 

[76zimmer]

ditto on the vent, is it backfiring, or just flooding out the vent?

 

[01maroonz71]

it slightly "backfired" once but it was just fuel that it shot in the air so ya i think its flooded

 

[01maroonz71]

so, i recon i should have it "re-built" again eh???? a GM tech did this rebuild. could the carb be shot???? or would it be something he did wrong???

 

[01maroonz71]

well, we took off the carb, and found fuel in just about every single vac. line.

so the carb goes back in tomm.

 

[ryoken]

I'd bet he hung the needle improperly on the back of the float and it's hanging up in the seat bore.... very common mistake..

 

[01maroonz71]

well, we just got the carb back and still no good....ran for like 5or6 seconds and shot fuel up and out again. going into all the vac lines as well still. the guys switched the needle around and switched it back the other way. is it possible that the rebuild kit was incorrect??? maybe float isn't right or something. the thing about it is that this guy did it under the table for my dad. for 75bucks. and the guy who ordered the carb rebuild kit(parts guy at dealership) also ordered a manual choke when it's supposed to be electric. so it's possible that he got the wrong kit, but wouldn't he notice when he assembled the carb???(the other guy)

 

[K5dreamer]

having worked at a chevy dealership, trust me, no one is above making a mistake. i was untrained and hadnt been working there a week when i was given in depth electrical problems, rear axle seal jobs, and even a piston ring replacement job on a Z06 corvette (i had been working there a good long while by that point, but was still not ASE certified). at this point, if you can, i would take the carb and vehicle over to the guy, or offer him a case of beer and a few pizza's to come over to your place and see what he can figure out.

 

[Hogback Fabrication]

Did you use a stock replacement fuel pump or an aftermarket one?

 

[01maroonz71]

stock replacement pump. same one i put on my GM crate motor from autozone. so we actually just ordered a rebuilt carb off ebay for 220shipped. my dad said he's tired of f'n with it. geuss he wants his jimmy up and runnin again. haha. im gonna keep the quadrajet and tinker with it...pull it apart and learn what i can about carbs.

 

[K5dreamer]

hey find that silver lining, i wish i knew more about carbs, i just never had a cause to work on em, i was part of the fuel injection generation. pretty much the only carb tuning i know how to do is set the idle speed and air/fuel mixture on an edelbrock carb. although my first car had a q-jet and i loved it, i just never had the chance to tear into it and rebuild it.

 

[01maroonz71]

same here man...im 23 and my truck is actually the first carbed truck i've owned. i know a good amount about FI but i am learning alot about carbs. what better to learn about than quadrajets eh??? i do know that my dad loved that carb before it took a dump. i love my edelbrock personally, and have had a holley that left me looking for more. mine's a DD though, i can say that my holley made more HP(seat of pants dyno) but seemed to tune itself. owell, to each his own i geuss. thanks guys!!!!
~Dave

 

[K5dreamer]

oh i love the q-jets, honestly, i wouldnt run any other carb, its such a wonderful combination of small primaries for good mileage, and those big honkin, get the women and children off the streets secondaries Im hopin to build up an old school hotrod with a big carbed engine (i wanna run flame throwers ) and it will have a Q-jet placed squarley on top of it i hope you dont let it go, and find something to put it back on eventually.