Rochester Quadrajet fuel problem

[acdc96]

So I just replaced the fuel pump on my 1987 Mercruiser 260hp V8 and I get all the air out of the lines. I replaced it last night at 10:00pm and decided to be nice and not start it up and disturb the neighbors. I try to start it and it would just sputter out. I would pump the throttle a couple of times and it would just sputter. If I kept pumping the throttle it would run but as soon as I would stop it stalled. I figured the accelerator pump was just supplying fuel to the engine. How can I check if the bowl is full or empty without taking the carb apart? I don't want to rebuild if I don't have to!!!

 

[MikDee]

Did you replace the little canister fuel filter in the body of the Q-jet? Be careful of the teflon washer on the flare thread, don't lose it.

 

[tinkerguy70]

Hey, just a thought here. But if you're getting fuel to the accelerator pump then you should have fuel in the float bowl. If memory serves me correctly, the accelerator pump is fed by a passage from the bowl.
I think you're going to have to take that thing apart and see if it's full of crud. The main jets are in the bottom of the float bowl and most likely full of gunk.

 

[four winns 214]

I am not a mechanic in any way, shape or form, but when I replaced the fuel pump on my quadrajet carbbed Merc 5L 228R, fuel leaked from the carb all over the place. I had the carb rebuilt by the local guru and the same thing happened after reinstalling the carb. Called Merc and they knew what the problem was instantly- the push rod operating the pump had too much throw. Their solution was to use thicker gaskets between the pump and mounting pad to reduce the push rod throw. That cured the problem. The specs for the push rod throw are in the maintenance manual. A little change makes a fairly large change in fuel pressure. Since your problem may be a lack of fuel pressure, the solution may be getting more throw in the push rod.

 

[acdc96]

I pretty much rebuilt the carb. It had white crap in the bowl, kinda looked like clear silicone. I replaced the gaskets. I didn't touch any of the mixture screws or anything cause I didn't want to tune the carb cause it was tuned perfectly before. I put white lithium grease on the surfaces where the gaskets contact. Old trick I learned to save gaskets if the carb needs to be undone to fix something inside. I hooked it up to the boat, dumped some fuel into the bowl from above, dumped a little down the intake. Had to pump the throttle a lot to get it going. I think I flooded it at first but it ran perfectly. It was running at a very low idle, between 400-500 rpm. Thanks all who replied!