Carbs or FI???

[LittleBlue914]

i know this is a very heated debate. with many supporters on both sides. (It seams a few more for FI though)

here is my situation i have a 73' 2.0 (scored a great motor with 26k original miles in my parts car). i currently am running the stock fi from the 2.0 and am having so many problems i am having to consider carbs (like a set of Webber 40's)
I'm no seasoned Porsche or vw mechanic but i know my way around a tool box.

I like the idea of keeping the stock fi (if it is practical to do so) but i cant see spending what it would cost for a 6 conversion just to make the stock fi work properly. the carbs seam a bit less complex, more straight forward tuning. Also i am not wanting to go as far performance wise as a more aggressive cam or anything, stock hp would be fine though more is always welcome i just want something i can get in and drive anywhere (sometimes just a little more quickly than others )

1) the car doesn't like to start easily, but that's understandable with a non functioning fi

2) on idle it runs rich!!! so rich in fact that my idle screw operates in reverse turning it counterclockwise will result in a higher idle this i have to assume is my mps (looked around but I'm pretty sure these are NLA)

3) power is minimal to say the least, it will go 55-60 just not as easily as it should

i have the enrichment knob on the computer turned completely lean and still not functioning properly all lines are new both fuel and air and connected correctly (thanks pelican for the diagram) fuel psi was 29 and from what i can gather that's perfect, i tried turning it down but still the problem persists

my valves are adjusted perfectly, timing is spot on, tune up is brand new, wires,plugs, rotor cap and button,i have electrical ignition in place of the points all hidden under the distributor, i even tried 5 gallons of 110 octane fuel and nothing

temp sensor II is brand new and tested as working in range, thermo-switch is functioning properly

if anyone wants to give me a helping hand with my fi please do, and if not let me know why carbs are the way to go. now there are a few questions about the carbs id love to have answerd

what can i expect MPG wise from dual 40's i really dont want a 4 cylinder getting 10 mpg

are they worth the cost vs fixing original fi (i think i can get a new set for around the $700 range, i would also need a new fuel pump)

also will throttle response be a problem with the carbs i wouldn't imaging so but i thought i would ask


Thank you all more than you can imagine, George



If only my enthusiasm where replaced by knowledge

[patssle]

On my 2.0 bus motor in my 914, I get about 20-23 mpg with my dual 40IDF Webers.

But that's on all of it's glorious 67 HP. /6 conversion in the works.

I have no problems with my Webers, haven't touched them in over a year for tuning or cleaning, they start right up every time with no problem, even if sitting for weeks.

[Joe Ricard]

SDS EFI. it will improve HP and MPG and run rock solid for ever. cost is not that bad considering what new Weber cost and still be driven crazy by a clogged jet.

[racer]

One great thing about FI is drivability. I found my 76 with FI much easier to drive than my 70 with dual webber carbs (on both the 1.7 and its 2056 replacement). easier starts, easier hot temp running. Not that the carbs were impossible mind you, but just a bit more involving.

That said, the old popular reason for switching was if the FI couldn't be fixed to run properly (thought this was usually the shortfall f the mechanic who was raised on carbs and didn't like
"computers and FI" to begin with. In the 1970s and 1980s, a switch to carbs was easy and relatively cheap. Nowadays though, not many folks know how a carb works!

I am no FI expert, but if you can get it working, it might be the better choice. However, some parts for the FI system are getting hard to come by and replacement costs are only likely to rise as this stuff becomes 40+ years old!

[tradisrad]

I say fix the FI. Start with this link: 914 D-Jetronic Parts and Troubleshooting It is possible to remove the computer connector and proble your components with an OHM meter. NEVER probe the computer with an OHM meter. Use this as a reference of what you are probing. You must down load the word doc. Downloads
once the FI is running well you will be pleased and have that $700 in the bank.
The stock type IV cam does not work well with carbs.

Slugish acceleration can be a faulty TPS. Also check the FI trigger points. CHT both hot and cold. Temp Sensor 2 does not do a lot. Besure the MPS holds vacuum.