Missing in my Carbed 302???

[Matts89LX5.0]

Motor misses in my 86 GT. Car was converted to carbed by a previous owner. Did plugs, wires, cap and rotor and the motor seems to miss from 3000-5000 rpms. It only happens in 2,3 when I floor it. It might be doing it in 4th gear but I haven't floored it. Car is all stock minus Exhaust I believe. I tried carb cleaner in the carbeurator. Could the carb be crap and need replacement? Thanks in advance.

Matt

 

[Matts89LX5.0]

2,3 meaning 2 and 3 gear.

 

[SmockDoiley]

So has it always done that? What carb is it, and how is it missing?

 

[maverick0716]

I had a similar problem with my car about half a year ago. I tried everything, from wires, cap and rotor, taking the carburetor apart.....and it turned out to be just what I dreading. Major vaccum leak caused by a malfunction of the intake manifold gaskets. (maybe from improper torque specs) but I replaced those and it's been running great since then.

 

[Matts89LX5.0]

the car kind of bucks between those rpms...it's been like that since I got the car, but I got it cheap enough that I figured it was because it was sitting for about a year.

Matt

 

[SmockDoiley]

what kind of carb is it? Also, have you checked the fuel filter. What kind of pump does it have.

 

[Dark Knight]

if it's been sitting, it's probably got some crappy gas as well as stuf plugging the filter... might be running out of fuel.. have you checked fual pressure, and what are you using for a pump?

 

[Matts89LX5.0]

stock fuel pump, i still have to change the fuel filter and air filter on the carb. Have not checked my fuel pressure and definitely not running out of gas...i'm thinking maybe at WOT its not giving enough gas through the carb.....Anymore input would be great.

Matt

 

[Dark Knight]

could be the pump starting to fail, run it up to when it starts missing.. and shut it off... pull one of the sight plugs to see if there's fuel in the bowls..

and you're running the stock FI pump on a carb car?
and can you rev it past 4-5k without flooring it?