I have noticed a lot of 914's for sale lately on Ebay, Craiglist, and here on 914World that have carbs. I was wondering what prompted these owners to scrap their FI for carbs? As a original owner of a 914 I know you have to stay on top of the FI system with maintenance and tender care. Was it because some teeners exchanged owners so much that it was easier to switch to carbs than to chase the FI problem? Or was it because there is a shortage of capable 914 FI mechanics that understand the D-Jet system or L-Jet system? This is not a knock on teener owners that have carbs.

i think it's absolutely a shortage of the skills required to keep these old f.i. systems operating properly.

i was almost there and might have well scrapped my d-jet. after going through the basics and still having no luck i took it to a local specialist and it turned out to be the e.c.u. cost me $600 to find that out though, probably about what i'd spend on a decent carb setup...

I got my first 914 in '89 and it seemed like the rule of thumb then was that you had to go to carbs if you wanted to go faster. IMHO, a lot of mechanics back then seemed intimidated by FI. I know it had been around a long time by then but working and tweaking carbs was easier for most.
I didn't really appreciate the reliability of FI until the last few years myself.

Could be both lack of FI knowledge as well as prior owners who had no clue.
I had a 2.0 built in the mid '80s and had dual carbs installed. The guy doing the build asked "Really?" and since I had already bought the carbs, he went ahead and used them. Looking back, I had no idea that staying with the FI would have been "better".

yep

You can't make radical changes to the motor with the stock F.I. That's the only reason I changed...

How's the availability of new/reconditioned parts? Based on a recent conversation offline, I'm wondering if cost or lack of parts might drive conversions in the future...

I think the lack of FI knowledge is the answer. There were not that many FI cars in the 70s and early 80s and even fewer mechanics who know how to work on it. As a result when something went wrong there was a tendency to blame the FI and the obvious solution was carbs.

John

I have meet so many people that flat out did not want to learn fuel injection then those that couldn’t learn. And a large chunk of these “mechanics” also flat out refused to use the proper tools to set up and tune carbs. If it wasn’t for smog laws even more of them would have been converted.

I also think that because the 914 was an entry level Porsche, many people that were not in a position to maintain them properly bought them and drove them into the ground.

The internet wasn't around to provide such robust information and support on mysterious systems. People were pretty much on their own and took the most expeditious way to keep their cars on the road. Look at all the encouragement new owners get nowadays to retain the FI. Many more would have switched to carbs if not for sites like this.

Advertising convinced a lot of people that more power was yours by merely removing the fuel injection system and going to one or two carbs. Some people equate engine performance to "cool" noises so the extra induction noise (and small reduction in flow resistance) was definitely perceived as a large HP gain by some.

Realistically, the size of your air charge size sets how much fuel can be burned so adding carbs either reduced power (single carb mix and flow issues), did nothing, or made a little extra power by over-richening the fuel/air ratio and/ or reducing intake flow losses.

Adding a cam with dual carbs could actually add more power but that involved an expensive engine teardown and a rebuild.

I'm one of those that like carbs. I even like MFI. They are both mechanical devices that I understand. In general people tend to stick to what they know. It's not that I can't learn FI I just haven't had a good enough reason to educate myself on it. Keeping your car smog legal and registered is a good enough reason for most. I just don't happen to have that issue in my State.

8 years ago I started working on old VW's with the D-jet and after a while the D-jet (and the L-Jet) are not that difficult to understand. I see myself as a teener (33 / build year 1978), I disagree that teeners can't work with this system.
The most common mistake people & teeners make is that they overlook the basic engine setup which is far more important than the injection system. But a lot of people see a lot of wires and go mad, instead of following simple things as timing / valve clearance / compression and the most of all the mistakes -> air lekkage before the cilinder head

Internet did help me find a book of the 80's with all the knowledge you needed to know, a simple flow chart.

When the 914 came out, not many mechanics understood fuel injection and took the attitude that carbs were good enuff fer my daddy and his daddy so I ain't gonna learn no forun car VW stuff that you don't see on Ford or Chevy.

By the time FI became common, most of the guys who did know anything about the 914 had retired. Thus, a definite skills gap.

The previous owner of my 914 spent over $2 grand getting the FI sorted out.

Another reason is that diagnostic equipment for FI did not exist in the 70's.

Even the oscilloscopes they had then were analog and could not even store a waveform.
Now they have digital logic FI monitors that give you all the information over the equivalent of a USB port. Any computer becomes the diag. equipment.

Troubleshooting a FI system in the 70s-90s required trial and error and often 'known good components' to swap out with the suspect ones to eliminate the culprit. Owners usually do not have extra parts laying around to test that.

When I converted my first 914 to carbs it was because I got it non-running with the FI in a box and I had more experience with carbs. Had it running for ~$700 with Dellortos.

Now I converted my latest because it is a race car and

Stu

when carb conversions were all the rage consider the price of NEW fi items. looking thru the AA catalog at new list prices back in the day...

mps new-1.7 $1411.18
2.0 $1370.97

fuel injectors new-$398.10 to $270.79

tps new $171.70 to $354.00

check out the pricing for various engine harnesses.

pretty staggering considering those were prices during the 70's not including labor. hell, a new oem 2.0 air filter housing was $1278.23. wtf!

"well sir, the mps in your 73' 2.0 is bad. that will be $1370 plus labor and tax. or we can just put carbs on it for you much cheaper".

k

After doing my engine swap from a 2.0 Djet to a 2056 w Ljet, I really have to say that trial and error is the only way to figger out some stuff. I have also found the Ljet to be a lot more simple, what with no trigger points, nor that mystical magical MPS... The main problems I had were 3 bad injectors, and a coupla vacuum leaks. Since then the car has run very well.

I still am not certain of the mixture, she seems to be running a bit rich, as I've gone through the exhaust for leaks, but I'm still getting some minor backfiring under decel in gear...

To me, the best way to check was to crank the engine with the injectors removed from the engine and squirting fuel into small jars; I used some prescription vials. If you're not getting the appropriate amount of fuel, then start working back from there, which may include swapping injectors from one cyl to another...

Then eliminate vacuum leaks...

It's time consuming, but not that difficult. ** Be the fuel injection**

My engine produced 147 hp on the dyno. How could I have done that with a stock fuel injection? It seems if you want more than a good running stock horse power engine, you go with carbs. (Or an expensive after market F.I. system).

Well--I'll be honest. My FI was kicking my ass. My motor was shot too, and there were so many issues, I just have up and carbed it. Now I have a built 2056, so no FI anyway. I know how nice the FI can be, but damn..it is nice to drive my car on a regualr basis rather than chasing down FI issues. No regrets...I also have the FI stuff in a box if I ever need it.

Yea, I have been chasing FI issues for 5 years now. The car will run great, then in a couple of months, another issue. Tired of messing with it so I JUST bought a set of carbs to do the swap. Hopefully by this weekend I can actually drive over 3k rpms.

Definitely a lack of knowledge within the industry. As a newer owner of a 914, I took my '75 with L jet into a shop advertised as something like "Michigan's number one rated Bosch service center". These guys were loaded with type 1's, type 2's and every model of Porsche that you could think of, all in for service. I had it in for a few issues, one being a high idle due to a decel valve issue. Upon pickup, I start the car and it's idling at 3000rpm....

I quickly decided that if I intend to keep the L jet that I'll have to learn to troubleshoot it myself

Since I put the Djet back on in 98 I have had one failure issue which was the Temp 2 sensor failed and I couldn't start the car. Swapped it out and off I went...so I still don't know why everyone has all these issues and failures.
On a 2056 120hp seems to be enough HP to bring a smile to my face. More HP and I'd go the 3.2 six route with FI.

from a shop's point of view:
the failures can be intermittent, hard to trace, parts are time consuming to track down, customers don't want to wait, labor costs get high, customers get frustrated because you can fix one thing, run it for a week OK and as soon as customer gets it, it flakes again. customer satisfaction index can take a beating

its easier to rip it all out and refurb the whole system from the wire harness up but most customers cant stomach the bill.
labor ends up being less and quality of result is higher when you refurb every part rather than trouble shoot in place.
this is a hard pill to sell

I would agree with most comments above
in summary : skill, profitability, cost, customer satisfaction

...but nothing beats the "click-vroom" of EFI