ok i have an 85 z28 with the quad jet carb... right now if i go wot it has alot of hesitation and does not want to go it wants to die it seems.. now if i am at part throtle its fine and i can get up to speed no problem.. now i have replace the fuel pump and fuel filter... my question is it sounding like it can be the carb or an ignition issue... and what do you guys recomened for me to change to get this car to work properly... please help i am running out of patience with this...

 

If the ignition is weak, all bets are off. A fresh tune-up, if not already accomplished, would be in order (spark plugs, distributor cap & rotor, and possibly spark plug wires).

The most likely carb culprit would be the choke pull-off. I just discovered a couple of weeks ago that mine was leaking and wouldn't hold the AV closed properly when first going WOT. The other possibility with something that has developed (vs. always existing) is the secondary rod hanger cam has a problem. The easiest way to determine this is, with the engine off, to open the secondary AV by hand and watch to see if the rods pull up smoothly with the AV opening.

 

ok i will check that to see... but now if i conclude that it is the carb what ideas for

 

Replacing the choke pull-off is easy - two screws, one vacuum hose, unhook connecting link, it's off. Back on is reverse with adjustment required.

The secondary rod cam is a little more complicated, requiring removal and disassembly of the airhorn. The cam itself is available from Rochester Carb / Quadrajet Parts Page (as is the pull-off if you can't find it locally - you should be able to find the pull-off locally, however).

 

sorry comp acting up but i will check the distributor and all the plugs... now if that does not help and i check the carb and that seems to be the problem what brand of carb do you recomend and what do you guys think of the edelbrock 1406 which is the 600cfm electric choke... for this motor... also do they make a rebuild kit for the distriutor and how hard is it to rebuild and whats the approximate price of that...

 

I doubt you need a new carb. But, since you have a 5-speed, I would recommend staying away from the Performer or any other non-mechanical-secondary carb such as a vacuum secondary Holley. They wouldn't be any better than the q-jet, and would probably be worse. For a 305 5-speed, a 600 double-pumper Holley would be much better. Either way, those carbs won't mount to a factory intake manifold, so you'll need to either get a spreadbore to squarebore adapter, or an intake manifold with squarebore carb mount provision. You will also need a vacuum/mechanical distributor - your factory distributor won't work without computer controls (unless this is a Canadian-delivered car).

 

so i would need to replace the distributor as well... now how hard is it to rebuild the factory q jet... this is my daily driver and that is the part that worrys me... the other question is how hard is it to put in a new distributor or to rebuild the old one and put the new parts in and is there a specific one you guys recomend more then any other ones.. also the edelbrock is not a good one to go with that is the one that all the auto parts places have been recomending to me so far and if i went with that one what distributor would i need to replace it with and what brand do you all recomend for that... and the car is an american car not from canada...

 

Rebuilding a CC q-jet isn't as bad as rebuilding a non-CC q-jet, in my opinion. But, doing it requires a couple of small special tools, I got mine from Checker, and a high-impedance volt/ohm meter (typically $10-15). I prefer the 1-gallon can soaking carb cleaner rather than the spray can stuff for the job, which requires a metal pan big enough to hold the carb throttle plate but not too big that the carb bowl isn't covered when it's soaked. Other than that, it's a matter of following the instructions that come with the carb kit and having a clean well-ventilated place to do the job.

The Performer needs the same type of distributor that the Holley would - vacuum/mechanical advance. The large-cap HEI is the most popular (looks very similar to what you already have - in fact, takes the same cap/rotor/coil, and the wires you need connect the same way). Right now Summit is having a special on an MSD unit, p/n MSD-8362, $149.99. That's a pretty good deal.

Most auto parts store guys are - guess what, auto parts store employees. Although they don't want to tick you off so you don't come back, their primary objective is the store's best interest. We don't have any reason to steer you one way or another other than knowing what works and what works better. We're not making any money off of you, so you'll have to decide for yourself where you're going to get the best advice.

 

ok i will check that out and see about rebuilding the carb.. i may just go ahead and also replace the distributor... now if i replace the distibutor say with the msd 8362 will that work with the quad jet or will i have issues with that...