Fuel System / AWD swap Questions...

[Daniel B]

Okay, so this is another one of those areas where I need to learn a bunch.

I'm converting a '94 FWD Impreza to an AWD drivetrain. With that, I'm installing the AWD specific fuel tank.

The old tank did not have the hump to allow the propshaft to pass under it and it was also from an ODB1 system. The new tank has the hump and is from an ODB2 car. I will be keeping the wiring from the ODB1 system.

I'm sure I'll have a few questions as I go, but here are the first two:

Because of the hump in the new tank, I believe that these cars had a second, internal fuel pump to move gas from the drivers side of the tank to the co-drivers side - where the engine supplying fuel pump lies. I have that second pump somewhare burried in boxes from a few years ago. Does anyone know how I can wire it for use? I don't have the wiring diagrams from a '97 Impreza. Or, although this makes me nervous, do I need the second pump? Here's a picture so you can see the hump that the fuel needs to pass over.

http://i471.photobucket.com/albums/rr78/123124125/questions/2010-03-18-1.jpg

Okay, second question; The '97 Imprezas had the charcoal evaporation canister located near the right rear wheel. The '94 has the canister located in the engine bay. I'd prefer to use the canister in the engine bay. In the picure below I've got a red circle around what I think is a pair of vents for the evaporation system. I didn't take any pictures of my old FWD tank, but I don't remember them being there. Can I just run a hose to connect the two 'vents' and then rely on the engine bay cannister to do the rest?

http://i471.photobucket.com/albums/rr78/123124125/questions/2010-03-18-4.jpg

Thanks!

[mrjobe]

Does/can the two and four door use the same driveshaft?

im starting a awd swap myself soon.

[bcorn]

Okay, so this is another one of those areas where I need to learn a bunch.

I'm converting a '94 FWD Impreza to an AWD drivetrain. With that, I'm installing the AWD specific fuel tank.

The old tank did not have the hump to allow the propshaft to pass under it and it was also from an ODB1 system. The new tank has the hump and is from an ODB2 car. I will be keeping the wiring from the ODB1 system.

I'm sure I'll have a few questions as I go, but here are the first two:

Because of the hump in the new tank, I believe that these cars had a second, internal fuel pump to move gas from the drivers side of the tank to the co-drivers side - where the engine supplying fuel pump lies. I have that second pump somewhare burried in boxes from a few years ago. Does anyone know how I can wire it for use? I don't have the wiring diagrams from a '97 Impreza. Or, although this makes me nervous, do I need the second pump? Here's a picture so you can see the hump that the fuel needs to pass over.

http://i471.photobucket.com/albums/rr78/123124125/questions/2010-03-18-1.jpg

Okay, second question; The '97 Imprezas had the charcoal evaporation canister located near the right rear wheel. The '94 has the canister located in the engine bay. I'd prefer to use the canister in the engine bay. In the picure below I've got a red circle around what I think is a pair of vents for the evaporation system. I didn't take any pictures of my old FWD tank, but I don't remember them being there. Can I just run a hose to connect the two 'vents' and then rely on the engine bay cannister to do the rest?

http://i471.photobucket.com/albums/rr78/123124125/questions/2010-03-18-4.jpg

Thanks!


I swapped my 93 Fail wheel drive to Awesome wheel drive last summer. It now has parts from 93-2005 in it. My tank came out of a 95 L. The wiring for the extra pump was tied in to the existing loom that was on the tank. It was plug n play.

That said. Last week I finished converting a 95 automatic L to a 5spd rear wheel drive and used a tank from a 96 Brighton (smaller, only one pump). To accommodate the auto/manual differences I pulled the whole harness from the 97 OBS I was scraping out and swapped it into the 95L. If I remember correctly the 97 had an extra plug for the second pump. I would bet that they are on the same circuit/fuse and that you could simply splice into the main pump wiring without problems. I would check the amp draw of the two pumps together and double check the fuse to make sure it will handle it. And if at all possible get a manual. There are many affordable resources around for manuals on cd. Even an old Chilton or Haynes from half price books is better than nothing.

You want to swap the cluster of hard/soft lines (3 lines/ fuel out ,fuel return, and vent) that are clipped to the tank from the old tank to the new. Then you use a piece of the unused hose to bridge the gap if necessary from where the vent from the tank to the vent line from the old tank. I will make more sense when you are looking at it. It will likely be just a little off. It think I had to slightly bend the hard line for the vent.

I'm drawing a blank on the charcoal. I will have to get back to you about that one. I will look at it again tonight.

I hope this is more helpful than confusing.

[bcorn]

Does/can the two and four door use the same driveshaft?

im starting a awd swap myself soon.


they are the same.