# fuel pump mod



## 13beetle (Jun 20, 2009)

does anyone know if i can just get rid of the existing pump and filter and regulator and put all new lines, aftermarket fuel pump and filter in a 16valve gti


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## ziddey (Apr 16, 2006)

*FV-QR*

you need a high pressure pump


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## WaterWheels (Aug 14, 2005)

*Re: fuel pump mod (13beetle)*


_Quote, originally posted by *13beetle* »_does anyone know if i can just get rid of the existing pump and filter and regulator and put all new lines, aftermarket fuel pump and filter in a 16valve gti 

Of course you can, but like was stated, you will find it hard to get the pressure and required using speed shop parts. Just a pump alone with the needed pressure will cost I'm sure $400 or more, I think more. For about $200 you should be able to find the correct pump new on the Internet.


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (WaterWheels)*

Na you can get a hp walbro for cheap, I want to find away to ditch the whole thing all together and just get a hp intank fuel pump.


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## ABA Scirocco (May 30, 2001)

*Re: fuel pump mod (eightwaysanta)*

THIS isn't exactly what you're looking for but, the Cabby in that article uses the same in-tank pump as your car so it might give you some workable ideas.
BTW, for any type of CIS, you need a minimum of about 80 psi; many fuel pumps designed for EFI systems won't give you that so take great care when selecting your pump.


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (ABA Scirocco)*

Wow thanks for poosting that link. I'm thinking of doing this myself. (i have a cis system)There are aftermarket high pressure intank pumps that you can get. I believe walbro , jegs, edlebrock have them for the chevs and fords. The pump in the link I think works for the v6 chevs.I found a high pressure intank pump for the v8 cameros that looks very similar to the mk2 pumps. heres the link. let us know if you do the conversion.
http://www.summitracing.com/se...k|Asc


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## WaterWheels (Aug 14, 2005)

*Re: fuel pump mod (eightwaysanta)*


_Quote, originally posted by *eightwaysanta* »_Na you can get a hp walbro for cheap

Walbro pumps, any I have ever seen, will not run a CIS system. The pumps you posted a link to are for EFI systems and also would not run a CIS system. EFI pumps for the most part only produce about 45psi +/- as the systems most times only run at about 35psi. As pointed out CIS requires much higher pressure and it operates based on its pressure so it has to be maintained high. The link posted on the "How-To" is also about EFI (Digifant) and will not work on your 16v unless you have converted it to EFI. I have only ever seen one pump as I recall listed on Jeg's or Summit that would run a CIS system and that was made I believe by Barry Grant for around $400. Do not confuse their flow ratings with their pressure as flow is not an issue at all. For CIS the Bosch or Bosch looK a like pumps are the cheapest way to go even if it does not seem that way at first. You can ditch the accumulator and use the older pumps that do not use a tank if you just want it a little more simple.


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## ABA Scirocco (May 30, 2001)

*Re: fuel pump mod (WaterWheels)*

Most of what you say is correct. Walbro does however make CIS replacement pumps, for example their GCL604 but it's pretty much a Bosch clone so it would be too large for this particular application. I don't know if there are readily available fuel pumps capable of running CIS that would be small enough to fit in the tank, I've not seen one hence, my earlier warning to take great care when selecting a pump for this application.


_Modified by ABA Scirocco at 6:27 AM 9-20-2009_


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (WaterWheels)*


_Quote, originally posted by *WaterWheels* »_
Walbro pumps, any I have ever seen, will not run a CIS system. The pumps you posted a link to are for EFI systems and also would not run a CIS system. EFI pumps for the most part only produce about 45psi +/- as the systems most times only run at about 35psi. As pointed out CIS requires much higher pressure and it operates based on its pressure so it has to be maintained high. The link posted on the "How-To" is also about EFI (Digifant) and will not work on your 16v unless you have converted it to EFI. I have only ever seen one pump as I recall listed on Jeg's or Summit that would run a CIS system and that was made I believe by Barry Grant for around $400. Do not confuse their flow ratings with their pressure as flow is not an issue at all. For CIS the Bosch or Bosch looK a like pumps are the cheapest way to go even if it does not seem that way at first. You can ditch the accumulator and use the older pumps that do not use a tank if you just want it a little more simple.

really, read the specs these are not stock pumps they produce 100+ psi for high hp apps where more fuel is needed.




_Modified by eightwaysanta at 8:12 AM 9-20-2009_


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## ABA Scirocco (May 30, 2001)

*Re: fuel pump mod (eightwaysanta)*


_Quote, originally posted by *eightwaysanta* »_
really, read the specs these are not stock pumps they produce 100+ psi for high hp apps where more fuel is needed.


That's just it, the specs are hard to find, that's why you need to be careful. For example, I had to go to 3 websites to find specs for the pump you linked to, it's a 65 psi pump, borderline at best for CIS and no where could I find the dimensions of the pump. And, the situation is the same for most of the pumps you see advertised on Summit Racing, Jegs, et al, the listings give you gph or lph and it may say "high pressure for turbo or nitrous" but they don't say how high, it's kind of frustrating. You almost need to contact the manufacturers directly and say, "here are my requirements, dimensions, pressure and flow rate, what do you have that will meet them?"


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## ABA Scirocco (May 30, 2001)

*Re: fuel pump mod (ABA Scirocco)*

Hey guys, I think I may have found one, the Walbro GSS-341, pressure and flow are adequate and it's SMALL. I've got a stock in tank pump at home, I'll measure it later.



















_Modified by ABA Scirocco at 11:40 AM 9-20-2009_


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (ABA Scirocco)*

I'm not sure where you got the specs from but the link I posted were for multiple pumps.the mustang pumps were 90psi, the edlebrock one was 100psi, the holly gm one was 110psi
what fuel sys. do you have? Let us know if it works. http://****************.com/smile/emthup.gif 

_Modified by eightwaysanta at 11:35 AM 9-20-2009_


_Modified by eightwaysanta at 11:36 AM 9-20-2009_


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## ABA Scirocco (May 30, 2001)

*Re: fuel pump mod (eightwaysanta)*

Alright I missed that but, there's still a big problem with the specs in those listings, they list the free flow rate and the maximum pressure but there's no indication how much the pumps would flow at let's say 80 psi. You can see from the graph I put up in my last post, the flow rate drops off considerably as the pressure rises. I suspect several of those pump probably would work but there's just not enough info is those parts listing to determine if a particular pump is suitable for our application. For our purposes, the free flow rate isn't very useful, neither is maximum pressure, to really assess whether a pump is suitable, you need info of the type presented in that graph or you need to actually test the pump. Oh, and it would be really nice if they gave us some dimensions.
I've got CIS and I have no immediate plans to change my fuel pump.


_Modified by ABA Scirocco at 12:42 PM 9-20-2009_


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (ABA Scirocco)*

ok heres some specs, also scroll down and click on typical high pressure 255 Ltr/hr for the graph of fp/amps etc.
the bently gives metric specs 12v - 760 cubic cm/30sec. does anyone know w/ better math skills than me if this pump (GSS340) is comparrable to the bosch ext. cis pump








http://www.autoperformanceengi....html




_Modified by eightwaysanta at 1:26 PM 9-20-2009_


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## ABA Scirocco (May 30, 2001)

*Re: fuel pump mod (eightwaysanta)*

Those are the kind of specs I'm talking about. Good find http://****************.com/smile/emthup.gif 
The recommended Bosch replacement pump for VW CIS system is rated at 148 L/hr @ 5 bar (39 gph @ 75 psi.) at 13 volts. so that's comparable performance to the GSS-340. That's more than enough fuel for something like 400+hp so either pump would be massive overkill for any naturally aspirated VW engine.


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (ABA Scirocco)*

awesome, now if someone could just get dimensions. Interestingly this pump lists as a replacement on early volvos. I think this one will fit.








I just found a holly pump 12-915 110 psi
Shipping Dimensions
L 5.250 in. x W 2.000 in. x H 7.000 in. 
Weight 1.101 lb.
I'm not sure if thats box size or item size either way its very close the the mk2 intank pump.


_Modified by eightwaysanta at 3:54 PM 9-20-2009_


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## ABA Scirocco (May 30, 2001)

*Re: fuel pump mod (eightwaysanta)*

Here's a picture of the stock in_tank unit from my Scirocco, the actual pump is 36mm in diameter, the hole in the top of the fuel tank into which the assembly fits is 49mm in diameter.


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (ABA Scirocco)*

my pierburg mk2 pump, is close to that about the same width, main body is a little over 70mm (2 3/4 in)


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## ABA Scirocco (May 30, 2001)

*Re: fuel pump mod (eightwaysanta)*

This pump's about the same long which makes sense since the parts catalog I've seen says your pump and mine are interchangeable. Anyways, when you add the pickup on the bottom and the fitting on the top, to total length of just the pump is about 4" or so.


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (ABA Scirocco)*

I found the walbro pump on ebay. I've emailed the seller to give me dimensions. Not bad price either Its about $100us. Way more cost effective than buying the 2 pumps or even just the external main.


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## antichristonwheels (Jun 14, 2001)

*Re: fuel pump mod (13beetle)*

Why would you even consider this move?


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## eightwaysanta (Oct 17, 2004)

*Re: fuel pump mod (antichristonwheels)*

because its cheaper than replacing both fuel pumps and rotted fuel lines


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