We kinda inherited an 87 LT with the 4bbl carb on it. It has sat for a few months while a lot of body work was done but now the fuel pump appears to be faulty because it's flooding the engine even after just a few cranks, like it's stuck wide open. We were going to try replacing the fuel pump on the motor and then we read that some 87s have a pump in the tank as well. As far as I know the only model that it would make sense to have 2 pumps is the 305 with the carb, since TBI and TPI would only need an in-tank pump. Is that right? Just trying to figure out what to debug first and if a bad fuel pump can cause insane flooding of a motor. Thanks

 

check the needle/seat/floats in the carb

 

Yup, sounds like something in that area. Sitting for so long the fuel that was in the bowl dried up and could have caused some deposits to be left behind hindering the float/needle/seat from shutting off the fuel to the fuel bowl.

 

One of my cousins who is the expert GM mechanic is gonna come take a peak tonight.

The motor was full of gas. Dad had to turn over the crank with a breaker bar because it was so flooded it didn't have enough juice to crank. Even the dipstick had gas on it. So it was bigtime flooded! But the carb on it is a steamy pile! When we go the car it idled at like 2800 lol. If it had the right torque converter it would be the perfect drag car... just a slow one heh.

 

I believe the fuel pressure is controlled by the mechanical fuel pump mounted on the engine. It is possible for old gas to gum up the return valve, which would cause the in-tank electric pump (and the mechanical pump, for that matter), to flood the engine.

At the very least, I would replace the mechanical pump with a replacement pump of the same type - the Carter M6626 is a good choice. And, replace the fuel filter. The gas should be drained out and replaced with fresh. The carb may also be gummed up by the old gas sitting in it.

What I would NOT do is replace the carb, replace the mechanical pump with a non-return type, or remove the in-tank electric pump. When in working condition, they all work very well together, better than whatever "upgrade" parts you might be told to put on.

 

And Change the oil ASAP! Before you try starting it again.

 

Yeah definitely needs an oil change. Probably needed it before we filled the oil with gas anyway. That should burn good on a camp fire!