Fuel pump replacement/upgrade advice please!

[Nubaroo]

Hi guys.

After many km`s the "in tank" pump on my daewoo started giving up the ghost. I am currently feeding from my intank pump to a high flow/pressure Bosch pump that is installed in the engine bay. This setup together with 700cc injectors have been sufficient to keep the Woo running the last yaer or so. Hoiwever today the car started loosing fuel pressure under boost at high RPM. The result is that I removed the standard "intank" fuel pump and replaced it with a Walbro pump. All seems to be well but 2 x things are bothering me - maybe someone can give me some advice:

The canister that the original pump is situated in (and the way the fuel return line works ) causes the fuel pump and it`s power connector to be FULLY submerged in fuel all the time even if the fuel level in the tank is on reserve. The new Wallbro pump is not a direct replacement and I had to modify the canister to get the pump to fit. The result is:

1 - the fuel pump DC connections becomes exposed ( not completely covered in fuel) once the tanks starts getting empty ( I drive like this most of the time as it is easier to change from pump fuel to race fuel). Can this be a serious issue i.e. can a loose/bad connection on these terminals (which in turn can cause a spark) cause the fuel in the tank to ignite??? I have heard somewhere that it is impossible to ignite fuel with any device/spark that is completely submerged in fuel as there is no oxygen for the fuel to be able to ignite, which would explain the reasoning behind having the pump completely submerged??

2 - I assume that having the pump submerged also assists with cooling of the pump - will there be issues with the Walbro if it is only covered with fuel most times round about 30 to 40% of its size submerged in fuel???

Please help as I am now too scared to drive my car as I might be sitting on a time bomb....

[PrecisionBoost]

GsiTurbo is over for roast beef and drinks.... he said the Lemans ( Astra ) has the same situation with #1 and there shouldn't be a problem.

I was going to say that perhaps you could put some good quality RTV silicone over the connections if your worried..... I'm pretty sure RTV is fine for gasoline.... but perhaps you might be best to check into that..... also you could consider soldering the connections.


As for #2..... well I have to think that the fuel pump not being completely submerged is not a major issue as the metal parts of the pump will conduct and transfer heat.

GsiTurbo says "hmmmmm.... hard to say " to #2

[Nubaroo]

Thanks for the input guys. Regarding No2 a friend of mine says that as the pump is feeding fuel through the middle of itself( helps with cooling), and as you have mentioned , some part of the steel pump is in contact with the fuel on the outside - all should be OK??? I have used insulated "push on" terminals on the pump that fits on VERY nice and tight, and I also crimped the wires onto the terminals with a PROPPER little crimper. I also tugged pulled on the wires quite hard and all was OK.

Have driven the car a few days now and all seems well

[PrecisionBoost]

Good to hear.... I think you should be fine.

[Nubaroo]

Good to hear.... I think you should be fine.

Thanks - taking the car tomorrow morning to have a "half roll cage" fitted....I have seen too many accidents on the dragstrip lately and all the guys that walked away from a crash had roll cages in

One always hope and pray that all will go well, but you never know what could happen....and if it does happen I just want to increase the chance of walking away as well.

Going to a PROPPER drag strip this coming Sunday where we run 400m, but carry on to 800m and also on to 1KM - the roll cage just adds a little bit more piece of mind LOL - I am guestimating I should clock round 248KM/H on the 1KM mark sitting on the 7000rpm rev limiter

I wonder how much a "half roll cage" would weigh - I supose not more than 30 - -40KGs???