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Engine Specific Info and Questions => IDI Engine => Topic started by: deadcaddy on March 31, 2007, 01:53:29 pm

Title: questioning vortex info
Post by: deadcaddy on March 31, 2007, 01:53:29 pm
Hey all, haven't been here in awhile.

I'm considering pulling the 1.6na out of my rusty caddy and putting it in a really sweet gti shell that I have committed to buy.

I read on a conversion post on the vortex that leaving the gas fuel pump in the tank(as a pre pump I guess) would offer about a 5hp gain.  Anything you can gain on an na is an improvement.

Do some of you guys that are a bit smarter than me think there is any truth or logic to that statement?
Title: questioning vortex info
Post by: jannemann on March 31, 2007, 02:26:01 pm
:lol: Dream on!

An electric fuel pump needs energy. That comes from the generator and that is driven by the engine. So theres no need to believe your engine would be strengthen...

Nice weekend for all.
Title: questioning vortex info
Post by: Kudagra on March 31, 2007, 02:33:08 pm
Quote from: "jannemann"
:lol: Dream on!

An electric fuel pump needs energy. That comes from the generator and that is driven by the engine. So theres no need to believe your engine would be strengthen...

Nice weekend for all.


I dont think it would give you any extra HP but it would help the injection pump and maybe keep it alive longer.
Title: questioning vortex info
Post by: Black Smokin' Diesel on March 31, 2007, 04:34:27 pm
Quote
:lol: Dream on!

An electric fuel pump needs energy. That comes from the generator and that is driven by the engine. So theres no need to believe your engine would be strengthen...

Nice weekend for all.


The electric fuel pump can compensate for a tired injection pump. I doubt you'll see any appreciable gains but an electric pump won't put any drag on the engine. It's not like air conditionning and power steering.
Title: questioning vortex info
Post by: Slave2School on March 31, 2007, 04:45:03 pm
Wouldn't you want a low pressure pump?  too high a pressure messes up the timing advance doesn't it?
Title: questioning vortex info
Post by: Op-Ivy on March 31, 2007, 04:50:31 pm
Quote from: "jannemann"
:lol: Dream on!

An electric fuel pump needs energy. That comes from the generator and that is driven by the engine. So theres no need to believe your engine would be strengthen...

Nice weekend for all.


It needs energy but the alternator belt is always spinning. It won't make much of a difference there.

I don't think it would increase engine power at all. But as others have said it could extend the life of your IP.
Title: questioning vortex info
Post by: jtanguay on March 31, 2007, 06:12:46 pm
yea i think it was you libbybapa who made a thread about how too much lift will affect timing  8)

i would rather just use the gas pump to prime the engine for filter changes etc.  would make that stuff a breeze.

anything in the 5 psi range is more than adequate.
Title: questioning vortex info
Post by: burn_your_money on March 31, 2007, 09:21:46 pm
GTIs don't have lift pumps in the tank, only the high pressure CIS pump. Sell if for $50 and buy a nice 5 PSI one

The intank pumps were introduced around 85 in the roccos I think
Title: questioning vortex info
Post by: deadcaddy on April 01, 2007, 06:07:06 am
thanks guys- that sounded a little off, but I wanted more opinions.
Title: questioning vortex info
Post by: knowtwodrugs on April 02, 2007, 07:33:40 pm
Quote from: jtanguay

i would rather just use the gas pump to prime the engine for filter changes etc.  would make that stuff a breeze.



Yup.  P.O. of my bunny added a fuel pump in the engine bay with a switch on the dash to run it.  Didn't know what the hell for, but left it on there as it definately makes those things easier to accomplish.
Title: Electric fuel pump
Post by: jimfoo on April 02, 2007, 10:03:54 pm
I had one on my Rover with the 1.9 AAZ. I think I found my recent inability to set the timing and get the engine to run after the rebuild was due to a high pressure pump. I had put one on just to help prime it after timing it, and it ran for crap and was hard to start. I had to advance it a whole bunch to get it to run good. With the electric pump removed, timed to where it should be, it sounds fine. I think I may have accidently had a 30-35 psi pump on it. So if you put an electric pump on, be sure it is low pressure or put a regulator on it.
Title: fuel pump
Post by: fatmobile on April 02, 2007, 11:28:49 pm
The MK1 GTI didn't have a pump in the tank but the A2 has a low pressure transfer pump.
 My '91 Golf runs with negative fuel pressure at the front of the pump. Even when it is shut off, it still shows a vaccum.
 This jumps up to around 10in hg when I really get rolling.
 A vaccum on the fuel line can cause air to be pulled out of the fuel and clump into large bubbles. I think a helper pump would reduce the bubbles in the fuel.
 I think most of the people saying it won't help don't have a fuel pressure gauge on their car.
 My '91 Golf was originally a gasser so it came with a transfer pump in the tank... it should be easy to hook it back up and check the fuel line pressure and butt dyno... some time this summer.
 I'm guessing it will help with power in the high RPMs.
 The few amps it takes to run the pump might be offset by the pump not having to pull so hard.