External Vs. Intank Fuel Pump

[CDNTurboZ]

This is for my 87 merkur xr4ti, but I would figure I would ask here as this info should be relevant to these cars as well. It runs a two pump system like the shelby charger, etc

Which is better external or internal walbro 255 fuel pumps?

I can see possibly the external one get less cooling as it doesn't have fuel to cool it down??

any thoughts?

thanks

[turbovanman²]

The only difference I can tell is ease of installation and ease of repair. The negatives to an external pump are it has to be below the tank as electric pumps aren't good suckers or you need an intank pump to supply the external pump.

[WVRampage]

Im using a inline pump on the rampage with the stock sending unit in the tank.

[CDNTurboZ]

Im using a inline pump on the rampage with the stock sending unit in the tank.

How's it for reliability, etc? any difference in priming?

The reason I ask is some of the turbo ford guys say it takes longer to prime, yet right now the car has only the stock external on it right now and it starts, and runs fine. I can't notice any problems with this 20 year old weak stock pump(the previous owner took out the intank one and put a sock on the end just so the car can be moved around)

[turbovanman²]

Thats the problem I said, electric pumps are good suckers, not pullers so if your too high up, you can get prime issues or pressure problems without a helper pump in the tank.

[Austrian Dodge]

i'd run a 255l/hr walbro in-tank and if theres a need for even more fuel, than build a catchtank and have an aeromotive a1000 pump out of it. ;)


walbro -> catchtank -> a1000 -> fuel lines
we'll see if i ever need this

[ShelGame]

Thats the problem I said, electric pumps are good suckers, not pullers so if your too high up, you can get prime issues or pressure problems without a helper pump in the tank.

What he said.

Been there, done that (the wrong way) and have the burned pistons to prove it...

I originally setup my S60 Bosch pump ~3 ft in front of my fuel cell, and a couple inches above the cell outlet. Everythign seemed fine, but sometimes I would get a strange misfire on hard accleration. Turns out the pump inlet was starving for fuel and causing me to go lean. I turned the cell around so the outlet point rear (fuel sloshes to the rear on accel), and I put the pump right at the cell outlet. No problems with fuel perssure now.

[CDNTurboZ]

thanks guys, I'm probably going to end up picking up an intank version, its only $127 CDN shipped to my door and its XR specific. As I don't want to be running lean!!!

[WVRampage]

Mine is mounted down low on the frame,never had any issues.

[Ondonti]

If you were doing it again, just keep your stocker pump in the tank.

You would be amazed how much more fuel it would move if it had to maintain about ZERO psi fuel pressure thanks to you having an external walbro.

Thats one of the reasons why a walbro inline with a walbro intake can flow about as much fuel as twin intank walbros...maybe more.

[Speedeuphoria]

Havent had any probs w/ my inline 255, was mounted kinda high, started and ran fine(not pushing it). I've since relocated it lower, close to bottom of tank. I replace the pickup w 3/8 tube flared stuck in the bottom of the little bowl. My return is also 3/8 but doesn't go back into the bowl. So far no probs.

I also hit the key forward, it turns the pump on for ~3sec,key on again then start. Sometimes it makes funny noises when priming, believe its air?