1986 Pontiac Grand Prix 2+2 Carburetor

It sounds like the 2 + 2 is stock so I would find a reputable rebuilder and have the original one rebuilt, aftermarket one's will not be a direct swap and will also require tuning to get them to run right on your 305.

You come to right place. Being "non-inclined" is a recipe to be taken advantage of. Don't be afraid to ask for help, but send pictures!

Send a pic of what you got, I might have a replacement.

Get used to doing research. If not specifically..., learn conceptually and you will be way ahead of most young mechanics today. The 86 does not have an OBD-II scan tool connection making most "new", "technicians" completely lost.

Like several others here, I grew up with these cars, been building/repairing and modifying Q-Jets since I was 14.

On your 86, the first thing is drop your tank, clean it out and replace all your vintage OEM fuel lines. New fuels at the pump will destroy the older "rubber" lines. This is true for any lines at the tank, or fuel pump to carb, or any return lines.

Nothing worse than to see your recent, fresh restoration catch fire and burn to the ground.

And don't buy into the 305 is junk myth. 305 is not a 350, but it is not junk.

Transmission if 2004R is not bad. It just needs rebuilt by a shop that understands it and can rebuild and modify it with better more resilient internal parts.

The original car for that year had soft cams. So, best is replace it.

Summit 1106 grind or similar is ok. With flat tops pistons, .488 or about lift and 230 duration and good HEI distributor, Edelbrock 650 carburator makes, nice steetable car.

NEVER install a rebuilt carburetor unless you don't need to turn your original in as a core. There are many differences between different number carburetors. There may be someone on this site that is able to rebuild it for you if it does need to be rebuilt. If you really want it rebuilt and don't want to tackle it yourself, I'm on the v8Buick site and there is a guy that just rebuilds Quadrajet carburetors and I have not heard one bad review about him.

565bbchevy said:

It sounds like the 2 + 2 is stock so I would find a reputable rebuilder and have the original one rebuilt, aftermarket one's will not be a direct swap and will also require tuning to get them to run right on your 305.

Click to expand...

That's exactly what has to happen with any carb, even the stock one if it gets rebuilt. The CCC carbs also need to be "fine tuned" again to the car's computer even when bench set. MUCH easier for the original carb to be done, but basically any carb will need some tweaking.

Your carb number should be 17069004. 2+2 cars IIRC, come with the 305 H code 4bbl engine (Non-H.O.)

If you're not going full bore modified with this thing and just want it to run like it used to, get someone to rebuild the original and keep the CCC. You'll be miles ahead. You cannot mix and match CCC components and expect goodness. Either all in, or all out. Which means you have to understand how it works, either way.

Carbs below.....

#1 is closed loop
#2 is open loop

Mix and match the wrong one and check engine light stays on. CPU will put car in "Limpy" which is "limp home mode" and will run like crap, terrible drivability and terrible fuel economy.

PorpoiseBlue said:

Hi all,

I have my uncles old 1986 Pontiac Grand Prix 2+2 in the shop, trying to get it running. It has been sitting for 20+ years.
The mechanic is suggesting I replace the carburetor, but I am unsure what I should get.

I believe the engine is the 305 5.0 V8 and I see multiple options.
RockAuto shows remans with Closed Loop (w/ Solenoid On Air Horn) and Open Loop (w/o Solenoid On Air Horn).

These appear to be more expensive than getting a new Edelbrock Carburetor, but I am not sure if those would be plug and play or if they would require some modification to get working.
I am not very mechanically inclined, if anyone can offer some advise as to what I should get, that would be greatly appreciated.

Thanks!

Click to expand...

In factory stock form , most G bodies including yours uses a computer controlled carburetor along with a computer controlled distributor.
No one makes a aftermarket computer controlled carburetor. You need to have the original rebuilt by a good rebuilder, and never exchange your carb for another. Without the correct carb your ignition will default to limp mode. These early systems are called Computer Control Command, CCC or 3C. Most modern mechanics are nor trained to work on these old systems or old cars in general. Many refuse to work on orders cars period.