First off these problems are occuring on an 84 Grand Prix stock 305 q-jet(LG4 i think). The problems first started occuring after the intake was replaced due to a broken bolt being drilled out incorrectly. I didnt replace the intake, my mother's friends did the job since I have school and work. I've been looking at the car when I have time. The problems and things that I have done are:

#1. It has lots of trouble staying alive from a cold start.

#2. I adjusted the driver side screw to increase idle(fast idle?) to keep the engine running while in Reverse or Drive but now causes it to idle in Park and Neutral too high. The idle would fluxuate in Park, Reverse and Drive.

#3. I was advised that it probably has a vaccum leak so I check all the hoses and they seem fine and in the right place. Also I replace the gasket between the intake and the carb(cured only the fluxuating idle in #2).

#4. Also right after the intake replacement the car had a code for the M/C solenoid but I cleared the codes a while back and the computer hasnt shown anymore codes.

The car drives now but it still has the high idle in Park or Neutral and a low(wanting to die)idle in Reverse or Drive. When driving it drives fine as long as the gas pedal is pressed slightly but once pressed to WOT and somewhat released, the car instantly dies. If I attempt to start it up again it wont hold idle and dies unless I give it gas. When I toggle with the linkage that moves the firewall-side lower-valves or flaps on the carb(secondaries?). Afterwards, I can start it up with the idle holding but if I press the pedal to WOT it starts the same problem again. Any advice would be appreciated. Thanks

------------------
Shouldn't bother putting this but hey what the heck:
1988 Maui Blue Firebird 305 TBI stock (w/ 190,000+ miles and still running strong )

 

Buy a can of engine starting fluid and spray it all over the intake, the carb, and all vacuum hoses while idling. When the engine revs up, you've found your vacuum leak.

 

I had all those exact same problems with my Q-Jet on my 85 Z. I did the vaccum leak test and no leaks found...I adjusted the high and low idle screws until i was blue in the face and it didnt fix a thing. I went and bought a rebuild kit....that didnt do anything either, so I bought another Q-Jet...used of course....car runs like a top. Thats my advice.

 

The Q-Jet that came with my '84 was doing this, too. I found out that there was vacuum leaking from where the linkage goes into the throttle body, wasn't sealing. The carb was also flooding, the plastic float had broken open and it just wouldn't float. I just went and got a reman'd one, still works great up to this day.

------------------
DR Stevens
1984 Trans Am 305HO L69
sucks gas, hauls ***
1991 Firebird 305 LO3
for days when I need a/c