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Posted by: Joec Jul 22 2021, 11:40 AM

Brand new to the 914 world. My car, a 74 2.0 was parked for 25 years, bought as a roller. Now missing the fuel pump( among other stuff) looks like it was plumbed for a 2 port pump anyway as 1 line to the injectors with a return line only at the end of the run, no y connector. I plan to replace all of the fuel lines so now is the time to place the pump. Seems real easy to place on firewall as lots of room there. I have read countless articles but not much recent stuff and most are vague with instructions assuming I have full comprehension of the car, which I don't. It sounds like stainless lines in the tunnel are a must, what fuel pump is suggested? Front or rear?,modify and put in tank?? Suggestions or point me to a current article. Any help really appreciated.

Posted by: ClayPerrine Jul 22 2021, 12:45 PM

There is a known issue with vapor lock on 914s. The fuel pump was mounted next to the heat exchangers, and hot weather would vapor lock it. The factory fixed in 75 by moving the pump up front.

I normally buy an Airtex E-8445 pump, and mount it under the fuel tank. Lots of people update the fuel pump using the 75 pump and mounting location.

And yes, the stainless steel lines are an absolute must to do 50 year old plastic is risky and can cause fires.

Good luck.

Clay

Posted by: rjames Jul 22 2021, 01:20 PM

Move it to the front.

Posted by: NARP74 Jul 22 2021, 01:34 PM

I have heard you can get by without the relocation by using some modern heat shield tube around the hottest areas, like DEI or similar. Chris at Tangerine has some experience and sells kits for the lines etc. I have the kit, not installed yet.

Posted by: mlindner Jul 22 2021, 01:36 PM

Joec, mine in a 914-6 GT Tribute for track but still streetable. For easy access I put the fuel pump in the front trunk. Best, Mark

Posted by: advman89 Jul 22 2021, 01:40 PM

Just ran this gauntlet.

The 1971 I got--the lines were shot--in fact, I barely touched one of the old lines in the engine bay and it completely disintegrated. Another anecdote--was in Phoenix at a Porsche junkyard and it was full of stacks of burned up 914s. Oh, and the insurance on this 1971 came in higher than my 964...so yea...fires are a thing.

I bought the the lines from Tangerine Racing. They were hugely helpful. Also had the relocation instructions/bits from Dr 914 at AutoAtlanta. It was a bit of overkill, but gave me a little flexibility on the mounting at the front.

It took me longer than it should have because I didn't have a second set of hands to run the long lines through the tunnel..but with two people a bit of motivation, it's an afternoon if you have everything you need.

Couple pics...and while you have that cover off in the front--might as well check to see if you need to replace your master cylinder...


someone told me early on...spend the money upfront...or spend the money on the backend to fix everything--but just understand, you'll be spending the money.

Posted by: willieg Jul 22 2021, 05:01 PM

I took some pages out of Tygaboy’s installation for my fuel pump installation. I bought a Tanks GPA2 fuel pump from Summit and drilled a large 3+“ hole in the top of the fuel tank, directly above the sump that is in the bottom of the fuel tank. The GPA2 fuel pump slid into the hole and the bottom of the fuel pump rests in the sump. Very tidy installation. Tygaboy being somewhat “touched” did another fuel pump installation which is also worthy of a think.

Posted by: KSCarrera Jul 24 2021, 03:19 AM

Posted by: 914Sixer Jul 24 2021, 06:04 AM

PLEASE do not use worm gear clamps on fuel lines. Use fuel line band clamps only


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Posted by: mlindner Jul 25 2021, 04:36 AM

Thanks 914Sixer, will change out. Mark

Posted by: 930cabman Jul 25 2021, 06:50 AM

Welcome aboard mate. I agree with the replacement of the original fuel lines and moving the pump to the front. How is the level of rust on your new 914?

Posted by: Joec Aug 7 2021, 02:41 PM

Car is rust free, had maybe 1 paint job in its life. Small hit in rear quarter, previous hit in front end. Hoping to get it running soon to assess the engine's health.

Posted by: SKL1 Aug 7 2021, 09:15 PM

Use a rotary pump in the front with Chris' (Tangerine Racing) lines in the tunnel... job done!

Posted by: Joec Sep 21 2021, 04:12 PM

All ready to order new stainless fuel lines for the tunnel and after talking to Auto Atlanta they suggest not replacing the lines in the tunnel as they are not prone to failure. Any thoughts? I had planned on replacing all of the fuel lines.

Posted by: brant Sep 21 2021, 04:17 PM

agree with all of the above.
the front location solves the vapor lock issue

also.... these pumps really are pushers... not pullers...
so although the factory got away with motor bay installation... its because they kept the pump low and allowed gravity to do the pulling for the pump.

front mounted is the solution
and the reason the factory used that location starting in 1975

Posted by: Jamie Sep 21 2021, 05:09 PM

And don't neglect to install fuel filters, I mounted before and after the new front mounted pump to catch any "stuff" from the old fuel tank.

Posted by: jcd914 Sep 21 2021, 05:59 PM

Not advise I would take.
The tunnel lines do fail and then you are sitting in a car with fuel inside with you. Not someplace I want to be.
They are almost 50 year old plastic not designed to hold the pressure of the Fuel Injection system, just the weight of the fuel in the tank. If you move the pump up front you are now running high pressure fuel through the plastic line.

Does AA even sell the SS lines?

Jim

Posted by: windforfun Sep 21 2021, 06:07 PM

Several older mechanics from Europe who have worked on 914s for many years have told me that the plastic fuel lines are bullet proof. Go figure. The added pressure may be an issue. BTW, it's advice, not advise.

Posted by: windforfun Sep 21 2021, 06:09 PM

People tell me that these kind of hose clamps produce leaks. To that I say it depends upon the kind of hose that you're using. I've used these kind of clamps for decades with no issues whatsoever.

Posted by: windforfun Sep 21 2021, 06:11 PM

Nope. I disagree. The right fuel hose works just fine with those kind of clamps.

Posted by: jim_hoyland Sep 21 2021, 06:53 PM

Move the filter and pump to front trunk; added a shut valve and pressure gauge . A lexsn shield was added to protect the set-up


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Posted by: nditiz1 Sep 21 2021, 07:11 PM

Jim that looks great I may replicate when I move it from the engine bay.

On the topic of worm gear vs band, I recently had to use the worm gear to get a tighter clamp when the band produced leaks. Possibly the crimp style band would be better than the screw type band.

I had a question regarding hose size. For pretty much everything I'm running 3/8 FI line. The 3/8 fits snug on the send line. The return line is thinner. While 3/8 fit I did need to use the work gear clamp. I'm using a 911 Fuel pump. The out end is very tiny, a worm clamp here allowed the 3/8 to fit, but a 5/16 probably could have worked. The fuel pump inlet is a struggle to make the 3/8 work. What is the normal setup for everything including the smaller fuel filter ports?

Posted by: jcd914 Sep 21 2021, 07:44 PM

I am an older mechanic, although I only worked professionally for 20 years (3 Porsche dealers,1 independent), short by some standards.
I have seen personally several 914s, where those bullet proof plastic lines failed and leaked without the pressure of the relocated pump and I would not trust them.
And 914s weren't even that old when I was working on them full time.

Jim

Posted by: windforfun Sep 22 2021, 11:14 AM

I guess it's time to go stainless steel. Thanks for the feedback.

Posted by: 914werke Sep 22 2021, 12:27 PM

Again .. MISINFORMATION!
Ill agree tunnel lines can leak in stock form, but the incidence is (very) low and usually the causal reason is more likely abrasion from PO tinkering than simple pressure.
While its true early cars (70-74) were equipped with tunnel lines that were not designed /spec'ed for the hi-pressure use of the OE FI pump relocated to the front,
I continue to see cars that had been converted like this & have been running & driving for decades.
The late cars 75-76 have PLASTIC (Nylon?) lines that ARE rated for high pressure.
My own experience from breaking many many cars is that the tunnel lines are usually quite pliable and are likley to continue to perform as designed, in most cases.

But use common sense & don't succumb to Internet FUD!
All these cars are nearly 50 years old & its doubtful that Hans & Wolfgang engineers spec'ed these components to last this long.
Add into the mix they carry fuel formulations that are significantly different from the 1970's ... IMO its not a bad idea to replace those lines (in particular early) but to bang the gong that "your all gonna die" unless replaced is irresponsible.

More importantly, if still equipped with OE lines check them at the exit of the firewall in the Eng. compartment.
This where they are exposed to EXTREME HEAT and can degrade crack & cause fires.

Fire away

Posted by: Joec Sep 22 2021, 02:20 PM

I would say where these lines exit the tunnel and enter the engine compartment is where I have some concern, the plastic or wherever the material is looks old, and while not cracked it certainly has had some exposure to heat, but the car has been parked for over 25 years so really not that much exposure. At this point and time I am just trying to get the car running to assess the engine's fitness. So it seems I am most likely fine with the existing lines. thanks for the comments.

Posted by: Steve Sep 22 2021, 02:55 PM

Back in the late 70's, i had a 71 that was victim of an engine fire. It was the lines in the engine compartment. Back then there was a campaign by Porsche to replace all of the engine compartment fuel lines on the stock injection. Those fabric covered lines are horrible. I also just pulled a tank on a 75 and the original fabric covered lines broke in half and made a mess.

Posted by: 930cabman Sep 22 2021, 03:36 PM

Replacing the original "plastic" fuel lines is probably not a bad idea. Does anyone know what the plastic is? I am new to the world of things 914 and have had exposure to a 1974 and (2) 1975 models. Yes, the original fabric covered fuel lines are very brittle and must be replaced, but the original plastic lines are pliable. Again, probably safe to replace with new St Stl tubing, but when?

Posted by: Steve Sep 22 2021, 04:33 PM

Personally it's cheap insurance, why not replace the plastic lines with SS lines?
Do you have to, probably not, but for the price why not? They are easy to install and cheap. I got mine from rotary914. On my car, I replaced everything that was functional rubber or plastic. i.e fuel lines, brake lines, suspension bushings and shift bushings.

Posted by: windforfun Sep 22 2021, 06:54 PM

Good job. Right on!!! Do you want to sell your car? I hate gasoline. BTDT.

Posted by: jcd914 Sep 22 2021, 10:47 PM

I'll disagree with your conclusion but no fire from me.

The thread is about relocating the fuel pump on a 74.
The 74 would have the early plastic lines not the high pressure nylon line the factory switched to for 75/76 when they move the pump up under the tank.
I have seen and worked on 914s where a tunnel line leaked.

So I can't recommend moving the fuel pump to the front and running pressurized fuel through the old plastic line.

Thanks
Jim

Posted by: wonkipop Sep 23 2021, 02:29 AM

I would agree with 95% of what you say here.
the lines in the tunnel i pulled out 2 years ago (74 model) were still pliable and in first class condition. external to the firewall were brittle and would break by just bending them. the brittle area extended maybe 6 inches or so back into the tunnel beyond the engine bay firewall.

i doubt anyone in vw or porsche believed the cars would still be on the road in the numbers they still are at this point in time.

i'd love to know what the material and who the manufacturer of those fuel lines was.
the germans are/were incredible formulators of synthetic materials.
i don't believe those fuel lines at that quality are available anymore, anywhere.

i think they used plastic with a view towards collision protection.
the only thing that concerns me about stainless steel is it is brittle.
but i guess any accident where the fuel lines have to survive being bent in the tunnel is going to be one a human will find hard to survive?

re vapor lock problem with cars with rear fuel pump.
the problem is the magnesium fan shroud.
on shutdown it is a heat sink for all engine heat.
it gets very hot.
radiates at the fuel lines as well as the fuel pump.
the problem was a combination of the exposed fuel line which was only gravity fed as much as the fuel pump. with the pump in the front that exposed bit of fuel line along the rear firewall could be pressurised to overcome the vaporisation problem.

i'm leaving my pump in original location and heat shielding the fuel lines.

i never had a vaporisation problem with my original fuel pump.
but i do have one now with a modern in line pump in the original location.
i think the modern pumps are even more vulnerable to the vapor problem than the original roller cell pumps.

Posted by: windforfun Sep 23 2021, 10:57 AM

My lines in the engine compartment are still soft & flexible. Only 48K miles. Just lucky I guess.

Posted by: porschetub Sep 23 2021, 02:23 PM

My experience was this...all my fabric covered hoses were really bad,plastic lines soft and not in any way due for failure,not worth me importing a kit to due to cost I did the hard lines in larger diameter truck brake pipe as I already had the right bender for it,then did the tunnel (pressure) line in late model VW blue HP EFI line .
Used FI hose and clamps and used the old return to run a wire to power my LP fuel pump up front on the steering rack.