85LT4Z28

ok let me start out by saying what i have done to my car... in the last month and a half i have replaced.... the carb, the fuel filter, the cap, the rotor, plugs, wires, fuel pump, removed the cat, removed the air tubes, the smog pump, replaced the air filter, pcv valve, the breather filter.... now i replaced all that to try and find the reason y my car wont do wot... it seems to be fine while not in load... and its fine first thing in the morning but 2.5 min. when i leave for work in the morning i cant hit wot again... with out a bog... now i know a gut that says he can fix the carb so that i can hit wot and it will be fine... now what are the odds that the carb is the problem... seeing as how i had just got a rebuilt qjet for my 85 z28 305 carb. from advance a month ago... when i do go to wot though it does not want to go it hits 3000 rpm and stops and holds there... now i let off the gas a little way and it goes... what is going on if any one knows pleasse help me....

Sonix

iTrader: (1)

I'd say it's a pretty big chance it's the carb.

Either your secondary lockout lever isn't adjusted right, so it's stuck locked out (secondaries that is), or your secondary rod/hanger is so far off that it's causing that, or the A/V tension is wrong. I'd bet it's one of these 3 that's causing your problem.


I don't think many members on here have had good luck with the q-jet's from advance.

You going to have the car to buddy to try and fix, or do you want to try it yourself?

85LT4Z28

i would like to fix it i just dont know much about carbs... thats been the biggest problem...

Sonix

iTrader: (1)

These threads seem to come in batches...

The thread right below yours now, has this in it;
https://www.thirdgen.org/forums/post...275-post4.html

With the car fully warmed up, check that. If it looks like that, it's a problem. If the lockout cam is DOWN, and not blocking the secondary throttle shaft, you're ok.

2nd - with the car off, try and push down on your secondary air valve door.
https://webdisk.ucalgary.ca/~jmknopp...ac%20port2.jpg
Look right above the purple arrow, about 1 ". That's the secondary air valve door. If you can push that down with your pinky, with the car off. You're ok. It should snap shut. If it stays open, or refuses to open until you put more force on it, that's a problem.

3 - The hanger and rods are probably not the problem. Even if they're wayyyy off, they'll still work a bit, and won't cause quite the drastic problems you're seeing.

five7kid

iTrader: (14)

If the problem did not change in the least when you changed the carb, the problem is most probably not the carb.

Weak coil and/or module will also do just what you say is happening. As can improper timing adjustment, and weak fuel pump.

85LT4Z28

i just got done working on my car and the carb was the problem... the people at advance told me all the stuff was ready to go ahead and bolt it on and they were dead wrong... the carb they sold me was the problem... the secondaries would not open and the fuel air mixture was a messed up... so i got a friend to go through and fix it all for me the timing is good on it and now wot i go... felt so nice to have the car actualy go....

Sonix

iTrader: (1)

Great, kinda vague description of what was fixed, but fixed is fixed so...