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Posted: Wed Dec 12, 2007 6:34 am
by MR2 Zig
so far as i know the GTV6 only has the one external pump. I have seen suction side fuel lines leak air into the system and not fuel out onto the ground before. had it happen on a Porsche 914 that was my first car.

scott

Posted: Wed Dec 12, 2007 3:08 pm
by x-rad
One new external pump and one old 3/4 inch line about 50cm long from tank to pump will be replace saturday...

Also, although it is a big ( and new 1 yr old) fuel filter, I will replace this too...

Posted: Thu Dec 13, 2007 11:59 am
by kevin
x-rad, one last thing on the fuel side. I had a problem with the u -bend just next to the filter, as the person before me did not put a spring in the pipe or use a correct bent pipe. so everytime the car got warm the bend used to close up which is strainge as the fuel should not realy vary in temp that much especialy if the tank is full . Maybe friction on the bend- who knows but it did close up. Clutching at straws here.

Posted: Thu Dec 13, 2007 1:45 pm
by x-rad
I eliminated the U bend a few years back. all new lines from fuel pump straight to engine bay where the fuel filter i located (much easier to change)

All line replaced from tank to engine both directions EXCEPT the main line from tank to pump.

will get to that.....

Posted: Sat Dec 15, 2007 2:19 pm
by x-rad
Today i replaced the the last piece of old hose (from tank to pump)

Strange thing: I knew there was about 9 gallons in the tank...the first five came out real fast...then the last 4 just trickled out in about 20 minutes.....

the gas cap was off and the recirculation tubing unhooked and fuel return line unhooked at engine.

I also put in a new fuel filter and kept the one way valve near the injection manifold. I refilled the tank with about 3 gallons of the original gas (which is new by-the-way)

Went for a long ride...started out with a little hesitation as the air in the line cleared...then she ran GREAT for 30 miles with only rare hesitation. Wow, things are great. Then we stopped at a gas station for some more gas. I put 3 gallons in. needle showed about 1/4+tank. pulled out of the station and she ran like shit again with the hesitation at almost every acceleration...

What's next...???? something blocking the gas flow in the tank??

Tomorrow I will get rid of the one way valve to see if that makes any difference. Also, I will wire up a separate relay to run the pump.

Anybody know what the tank outflow pipe (Big banjo Bolt) looks like inside the tank (is there a screen or something)

Posted: Sat Dec 15, 2007 4:25 pm
by ar4me
I wonder if the tank does not get vented as you use your fuel = under-pressure gradually builds to the point where the fuel pump can't overcome it. Though, that does not fly with refilling and then having problems since pressure would be equalized during fueling... But, why would last 4 gallons trickle out slowly :?

I think you need to hook up a fuel pressure gauge and monitor pressure while driving and see if it drops causing the hesitation.

Do you have a spare tank you could swap? I have a 2.5 Milano tank that will go to recycling soon - perfect. Not sure if they are the same...
Edit: never mind, they are different, filler is on opposite side - duh...

Jes

Posted: Sat Dec 15, 2007 6:15 pm
by Greg Gordon
Inside the fuel tank ,just above where the fuel drains out to the pump is an in tank filter. It's sort of like a sock. I suggest you remove it and replace it with a clear filter outside the tank between the tank and the pump and monitor it for debris.

Greg

Posted: Sun Dec 16, 2007 6:04 am
by x-rad
could be the sock, then....any tips on removal greg??

Posted: Sun Dec 16, 2007 7:40 am
by Greg Gordon
Not really, my memory on this is a little foggy, however it's designed to be removed easily so it should not be a big problem. Remove the fitting at the bottom of the tank and the whole thing drops out. If that's not it, it should be self explanatory when you look under the car. Of course it helps to drain all the fuel from the tank first.

Posted: Sun Dec 16, 2007 10:34 am
by x-rad
Ar4me: no tank vac causing slow flow as fule fill cap was removed...

That trickle of fuel is probably as GG says the 'in tank' filter....


and it makes some sense that when I take a turn left or right, the problem gets worse....maybe the filter is broken and flopping around or collapsed..

I did not see anything about this on cardisc or in my manuals..but makes sense as I always wondered why there was no visible filter BEFORE the fuel pump.....

I will add a 1/2 inch inlet/outlet filter into the external drain line to pump and tear out any 'in-tank' filter

Posted: Sun Dec 16, 2007 10:35 am
by x-rad
Ar4me: no tank vac causing slow flow as fule fill cap was removed...

That trickle of fuel is probably as GG says the 'in tank' filter....


and it makes some sense that when I take a turn left or right, the problem gets worse....maybe the filter is broken and flopping around or collapsed..

I did not see anything about this on cardisc or in my manuals..but makes sense as I always wondered why there was no visible filter BEFORE the fuel pump.....

I will add a 1/2 inch inlet/outlet filter into the external drain line to pump and tear out any 'in-tank' filter

Posted: Sun Dec 16, 2007 11:00 am
by Barry
South African fuel tanks don't have a sock or anything in the tank..Banjo bolt out,nothing above it.Thats why you have the main in line filter..Trust me,Ive had my pinkie finger in there already..
Sorry,came in late here,just replied to what I saw Greg post..emphasis on South African Greg.. :wink: :D

Posted: Sun Dec 16, 2007 12:23 pm
by x-rad
Barry, is THAT what they call it down there....a "Pinkie"????

just don't go gettin it stuck in a hole somewhere :D :D

Thanks for the tips!

Posted: Sun Dec 16, 2007 6:17 pm
by x-rad
so some time soon...as soon as its not -10 out...I will pull and clean and seal the gas tank..

http://www.kbs-coatings.com/KBS-Gas-Tan ... r-C38.aspx

Or just get a new one....

http://store.summitracing.com/partdetai ... toview=sku

Anyone clean out their tank and have any tips??

Posted: Sun Dec 16, 2007 8:33 pm
by MR2 Zig
x,
you could take it to a radiator shop and have them boil it out. that will get rid of any rust or other junk. Then use KREEM or some other coating for the tank if you want.

I think the factory left the tanks bare on the inside.

I take it you found a bunch of junk in yours that was plugging up the works. You may want to check the inlet screens on the top of the injectors at this point also.

hth,
scott