no modifications, just my 172,000 mile computer controled quadra-jet, was aparently rebuilt back in 03'

for the past few days, if i go to WOT, it will most of the time kick down to first gear and then shift to second, then bog out bad... to the point where the car almost stalls and sometimes does. i was thinking this was my fuel pump since it did things very similar to this when the last pump went bad, but i changed that today, and conditions were no better then before. the problem seems to be gradually getting worse. what in the world is wrong with this carb?? and how hard is it to fix?

 

easy stuff first;

-fuel filter, $2
-push on your secondary air valves, how easily can you flop them open? pinky finger pressure? breathing on them? (car off for this test)
-choke pulloff, does it hold itself in? remove the vacuum line, push the arm in, put your finger on the vacuum line, does it still retract out?

 

Fuel filter (inside the inlet nut, that the fuel line screws into)Don't fix it, just replace it. Very easy if you have a 5/8" line wrench and a 1" open-end. Very much a PITA if you don't have the right tools and try to do it anyway and you trash the luel line nut or kink the line by not holding the inlet nut still.

 

i should add, that i changed the filter not even a year ago when i put the pump that i just pulled off on, the fuel line, it is a little messed up, but not kinked, and its been fine like this for an awful long time now.

when i get the change i'll have to try what was sugested, also i should add that its starting to get worse, driving at any more then half throtle is a pain anymore, and getting up to highway speeds is somewhat of a chore with it wanting to bog out constantly.

EDIT: just for referance when i was driving home tonight i made 2 WOT runs from about 10mph
first run: going up a slight hill.
punched it from 10mph, car downshifted properly, shifted at aprox 4700 like always, then immediatley dogged at about 3000 going up a slight hill, and as i kept going up it kept getting worse, and would be bounceing between 1500 and 2000rpm and going all of 25mph, very miserable

so i got to the top coasted for awhile and i could accelerate somewhat normally again.

seond run: flat road
punched it from 10mph, car downsifted properly, shifted at aprox 4700 like usual, then sorta stayed around 3000 for a second and completely stalled out, but restarted when put in to neutral and cranked.

 

does sound an awful lot like fuel delivery, since it'll go at first, then bog after...

but yea, one tank of bad gas, and your filter is junk. Since it's a 6 minute job, and a $2.50 part (for me in Canada, probably cheaper for you!), i'd still do that first.

2nd, i'd try and rig up a fuel pressure gauge at the carb, and go for a spin and recreate the problem. Make sure you've still got 5+ psi when it's doing it's bog.

3rd i'd check float level, and needle/seat assembly.

 

ok, i can put a new fuel fiter on in no time, i'll do that after work tommrow.

also, i'm a releative newbie to carbs, how do i go about checking the float level?

 

pop off the air horn, push the needle side of the float down, and measure the floats height. This isn't something that would become maladjusted over night, so i'm not so confident this is your problem. I'd be inclined to think junk in the needle/seat area.

 

alright i replaced my fuel filter today, old one was cloged up prety good. the car is "driveable" now, large improvement. but it's still not right.

it just seems to have a real hard time pulling in the upper RPM range (3000-4700), it will edventually get there but it will fall off and pick up a few times in the process. i looked at all the vaccum lines, they seemed fine.

when it quits raiing i'll inspect it better.

 

Not impossible for stuff to have got forced through it or otherwise got past it, and now your carb is full of gunk. Almost for certain in fact.

 

and how abouts would i go cleaning it all out? run some seafoam through it?

 

i'm starting to get seriously mad with this car, but its definately seeming to see like its a fuel starvation issue, as it got in another one of its moods tonight where it didn't want to go about 2200, so i got mad threw it into neutral and reved it, it would only rev to about 4500, so i let off did it again and it reved to 5000 no problem. it seems to have all the signs of a bad fuel pump, i have half a mind to put yet another new one on it to see if it fixes it.

 

i know the feeling right now i have an 85 z28 5 spd and i have the q jet and am having the same problem. that at half throtle its fine at wot it bogs down and wants to die on me.. had similar prob. befor threw in a can of b12 and ran fine now have same prob again so i gues i need to replace my fuel filter.. where exactly is it located please help

 

on your car it is where the fuel line enters the carb with the aircleaner off disconnect the fuel line, and then remove the large nut, and out it comes.