Any opinions on using a universal fuel pump that's in line? This would save loads of money. I just want to make sure it's fine to do.

 

If you are thinking of replacing a pump that is in the tank, with an inline pump because it is easiest, it probably wouldn't work. Cars with an inline pump normally, if not always have the fuel outlet at the bottom of the tank, because most inline pumps will not draw fuel, and if they are on a car where the fuel comes out the top of the tank, they have what is called a prepump, like a Rolls Royce has, to feed the inline pump. Inline pumps, that the old Jags have only put out about 3 or 4 psi to feed carburetors, and not enough pressure for any kind of injection. They were in fact electric mechanical pumps, with a rubber membrane and one way valve. I have not looked at my Jag, but many cars have an access panel in the trunk to get at the in tank pump. We can only hope.....Hope this answer helps.......Be cool.....Mike

 

If the in line pump is putting out up to 70psi would that make a difference? I'm doing it to cut the cost about in half. I'm not too worried about the difficulty. The way it was explained to me was I could go in the tank and take off the intake and output hose off the pump and connect those. Then splice in the new in line pump with a regulator to slow the output.
If it's sketchy to do then I'm not gonna risk it though.

 

So long as you have fuel down at the pump inlet without the pump running, you are OK. If you don't have fuel pouring out of the line, before the inlet most inline round pumps won't draw fuel, because they aren't made to. They are simply a motor with vanes on a shaft, kind of like an air tool in reverse. They are cooled by the fuel going through them, but they create very little if any vacuum to draw fuel in. Let me know how your experiment goes. I think a lot of us would rather put a pump in the line, than go into the tank. As for regulating the pressure, there is usually a pressure regulator already on the line, either before the injectors, or at the end of the line after the injectors, sending the excess fuel(bleeding off the pressure) back to the tank. If you are already putting the pump in the tank, it will work, but many tank units for the pump, also perform the fuel gauge function. A late 80s early 90s Corvette pump comes with a sock filter on the bottom, and would work well for what you are describing, and you would only need to hook up the outlet line, so long as you find a way to keep the pump on the bottom of the tank. Like I said before, once the fuel level goes below the pump level, you may not get fuel. I am an advocate of using parts made for the job. It takes 10% of the time to install them, and they work without experimenting.....Be cool....Mike

 

I would agree with Mr. Plow on using a factory replacement. It is a PIA to do it and not the simple or cheap. On the other hand, most likely you will only do this one time for as long as you own the car. It's not like owners replace fuel pumps every year as part of routine maintenance. What you are proposing might work, but if it doesn't or you have trouble down the road, in the end it may cost you more aggravation, time and expense. Penny wise/pound foolish comes to mind here. Weigh everything up and see what makes the most sense for your situation. Sometimes it is best to just bite the bullet and get it done so you know it works the first time. Good luck and let us know what you end up doing.

 

Thanks guys. I'm not one to take too big of a financial risk. So I think I'll be going with the factory pump. If I had more time and money maybe.

 

You might want to do a search on how others have done this. Some have cut a hole above the tank to access it instead of dropping it down.

 

jarrod, the question that you need to answer with the inline pump idea that you is "how much suction pressure does the inline pump need?". Some pumps work fine with a vacuum on the suction. Others need a positive pressure. This is where having the "pre-pump" would make a world of a difference. I think you are going to find that if you have an inline pump capable of outputting 70 psi that it is going to require a positive pressure on the suction. Otherwise, the pump would need an additional stage which means the pump is going to work harder since it has to raise the pressure more which can lead to a higher current draw which may be too much for the fuel pump computer (remember, the controller pulses the fuel pump to maintain the desired fuel pressure, there is no fuel pressure regulator like older cars have).

If you have more questions about this, let me know.

 

All sounds too risky to do since I need the car. Thanks guys.
If I didn't need the car I'd give it a try.