My 1975 914/6 GT clone with a 3.0 has not been running for several months. It has Weber carb's and it is running WAY too rich. I think the right bank has an issue with the floats. I've been very busy with lots of projects and haven't had time to get to her. To be honest I don't have time to get to her now but I have to plan on what I'm going to do. I have several options. One would be to fix the Webers. Two would be sell the Webers as partial payment towards new PMO's. I love the PMO's on my SC I haven't had to touch them in years. Third option is going EFI. A little over a year ago I purchased from Jake Raby a Autronics ECU with complete wire harness that he used for test mule engines. I also have a Carrera intake manifold with throttle body, fuel rails and injectors. The carb's I could do myself the EFI would be done by a pro. So what would you do ?

Carb fix sounds easy...but I prefer FI.

Have you checked with http://www.PerformanceOriented.com/ ?

I know the guy there does fantastic work. Might be more cost effective and almost PMO good.

As cool as EFI is, it'd be easier to learn/maintain carbs since you already have a car with them.

There is nothing better than reaching into the window and starting the car on the first click with injection!!!

Once you go EFI, you will never want a carb again!

At this point, I would only use a carb for a vintage resto.

Do a search here for bitzracing. I have that on mine.

--brett

Call McMark for a turn-key megasquirt system.

Fuel Injection just seems to work better.

I thought mark's system was for a 4....

--brett

I'm a carb guy, but FI will automatically compensate for altitude changes.

Mark can do a Six. The throttle bodies is the hardest part to get. Everything else is pretty easy. You would have to buy some dyno time to fine tune it... You could always spend $6k-$10k on a MoTec system...

Depends what your objectives are. Ultimately FI will give better performance unless you enjoy tweaking carbs to adapt to changing ambient conditions. But carbs are period correct and there is a certain amount of respect for someone that gets them right.

I love a good set of carbs because of the satisfaction of getting them right and due to the period correctness. That said however, I loved the stock FI system on my '74 2.0. Just turn the key and it always started and did it's warm up thing w/ no drama.

Bitz racing megasquirt + PMO throttle bodies =

What I've been thinking of doing is a Bitz racing megasquirt, keeping the FI system stealth and using my Webers as TB's, You could just replace the venturi's with some straight pipe.
The big trick would be modifying the manifolds with injector bungs.

Guys I already have a EFI ECU ( Autronic ) so why would I buy another ? And I've already had a Megasquirt experience and I'll NEVER do it again. I need to think this over some more and talk to some local tuners about the Autronics setup.

The bitz kit comes pre and specifically tuned for the 6. The PMO throttle bodies and rails would work with any ecu that uses a GM tps (I believe).

Bring it down to Rothsport. They can do a trick efi... For about $8k.

The PMO throttle bodies, manifolds and rails are around $1900 - $2200 as I recall.

I figured i could do a bitz kit with PMO's for just under $5k.

As soon as I hear this I think that having your carbs rebuilt by Performance Oriented and dizzy recurved or a pro built (Autronic is more of a pro-tuner system) and tuned EFI system makes little difference, whip out the cheque book and get 'er done.

The other option is to pay someone to put your 3.0 back to the stock CIS.

Carbs or EFI you have to do your homework and learn as much as you can or pay an expert to do it for you.
The Bitz racing MS comes loaded with a base 911 MAP and is aimed more at the DIY'er crowd.

The dizzy is already recurved for the carb's on the car now. Car has run strong in the past but all of a sudden pig rich that's why I'm thinking maybe a float is bad. I'm leaning towards having the carb's rebuilt.

Because aftermarket EFI was probably in its infancy when that ECU was made. Lots of improvements have been made. Why do you think Jake let you have it? SMC? SM2? SM4? The support for this ECU is in Australia.

Any aftermarket ECU is only as good as the guy tuning it. Newer ECU have much better features and more ability to fine tune.

I have used several types over the years. For my Audi conversion I opted for a factory ECU with a custom flash. There is way more R&D in a factory ECU than with any aftermarket...

Good luck with whatever you decide...

While you're deciding on which induction system you ultimately want, pull the existing carbs, remove the jets and blow carb cleaner through all the orifices, jets and the needle valves, then throw it back together to see how it runs. If it ran well previously, it should run fine again

You are not telling us the whole story and what parts you do have. I see your ad over on Pelican and you have a 3.2 manifold all the goodies to go FI and now you want to trade that for a set of used PMO's.
http://forums.pelicanparts.com/porsche-911...-efi-stuff.html
With that plan you just end up with used again.
You also don't say if your engine is bone stock or has bigger cams, you didn't tell us that the diizzy was recurved....missing a lot of pertinent information buddy...





Of course I would try cleaning the carbs first.

If you want carbs get your Weber's rebuilt to like new 42mm spec at Performance Oriented Or sell everything you have and buy new PMO's.
If you want FI get the Bitz and get a pro to install it if you are scared of it. The Bitz MS comes loaded with the base 911 3.0 MAP and has a known track record.

If that audotronic is Crimson axes (user name on STF) old unit it's over 10 years old now, needs a pro to MAP it and I wonder if they even support it any more.
Ebay it.

....and how come you didn't offer to sell that stuff here first.

The engine is a stock 1978 3.0 with recurved dizzy for carbs. I'm running a multi-spark CDI for ignition. The Weber's are 40mm and are jetted for the 3.0. She was running fine and then I let her set for a few months and when I went to fire her up she was pig rich with fuel coming out of the dual exhaust.
The aftermarket stuff I have is the Autronics ECU that I bought from Jake, a 1985 Carrera intake manifold with throttle body, fuel rails, injectors and I think idle stabilizer valve. Jake purchased virtually one of every ECU on the market to do his own testing, this is one of those test mules. In regards to trading for a used set of PMO's I would have no problem with that at all. I have them on my SC and love them.

Personally I would first replace all my fuel lines and filter as you will have to do this anyways. Then clean my carbs, if they look like this they are leaking at the shafts.


Stock SC cam and the stuff you already have, then EFI would be my choice. My choice would be Bitz or SDS as I would never go with a system that I didn't understand. I'd put the factory FI back on first.

If you want used PMO's they must be jetted and set up for your engine.

I know you are talking about 6's but has any one tried the CB performance F/I on a 4 cyl?

I don't know about their new system, but their old system sucked donkey balls.

It doesn't matter what system you use, you must either do your homework and understand the system fully or pay a pro to do it. SDS is probably the easiest of all the aftermarket systems to to learn/use, but you still have to be able to do up your fly without getting your beans and frank caught in the zipper.

To a lesser extent the same can be said about carbs as well.