I got my 914/6 back up and running with the 2.4S conversion parts, including the MFI!! God, I LOVE the sound of MFI at full song! With the S cams it has the same scream a 917 has.


Friday morning I was running the car, tweaking some little things when the injection pump died. I only have one S pump, so I was forced to remove the MFI from my six. It will take 6 to 8 weeks to get the pump rebuilt, and I have to have a way to get to my new job on Monday. So, under duress, I installed my set of 40IDA3C Webers. I rejetted them to the settings mentioned on the Early S registry for a 73 2.4S motor.

Main Jets #32
Venturis #135
Air Correction Jets #180
Idle Jets #60
Emulsion Tubes F3

Now I have to deal with all the carb crap.... like clogged idle jets, out of sync air bleed screws, UGH!!!


Has anyone found a way to keep the idle jets from plugging up? I have been working on the car off and on since Friday, and have cleaned the idle jets 5 times.

I still have to lower the accelerator pump stroke to lessen the black smoke under initial throttle opening.

The car runs ok, but it doesn't run like the MFI does.....

Carbs suck. Fuel injection is sooo much gooder ...

Andy

Actually; carbs do suck, and fuel injection blows!

Set up correctly, either will do the job, but there is something magical about a well set up MFI system. I'm always in awe of the engineers that figured out those three dimensional space cams in the MFI pumps.

Who are the good rebuilders of these pumps these days? There was a fellow in Rockford, IL, but he passed away a good number of years ago.

Gus at Pacific Fuel Injection.......

Mark Jung, too:

http://www.markjungoutlaw.com/

Good fuel filters and air filters are the only way to keep them from plugging.

It's a little pricey for me but you can buy this NOS pump off ebay right now. It has a buy it now option with free shipping.

http://cgi.ebay.com/ebaymotors/Porsche-911...eQ5fCarQ5fParts

That is not the pump I need. That is a 964 pump, and it doesn't have all the stuff necessary to run it on the street. I have an 69 S pump, but it will have to be rebuilt.

I have the K&N Watershield air cleaners. Any recommendation on fuel filters?????

I figured that wasn't your pump. The $21k price tag would blow my budget.

I like the metal filters. If you stick with the major brands they usually have more folds giving you more filter area and they usually filter smaller particles.

Dont you have a filter/cold start console with your mfi ? If you dont thats prob. what killed your pump.

best filter around

Factory for that engine.

Just got my pump back from Robert at Jerry Fairchild Industries in Redding. It's where a lot of the other "tuners" send theirs and double his price upon returning it to you.

K&Ns? There's your problem. The dirt particles they let through are easily the jet-clogging size. Get yourself a proper OE air cleaner and the correct pleated paper air filter. Less filter area, bigger pores = more air flow. More dirt, too. And more of that macho "look at me" noise, as well.

The Cap'n

Idle jets get clogged from K&N's? Hmmmm

My theory was that to avoid clogged jets was to clean your tank. As you drive, the silt in your tank gets ground up into particles so fine that they go right thru the filter.

But yeah, to me webers make better desk ornaments these days and motronic is too civilized for 914-6. Congrats on pulling off an mfi - I chickened out on that.

21k?

i won't be playing in the that park!

K&N's are meant to be cleaned and oiled. They have bigger holes for junk to get through than a paper element. Thats why you get a HP increase with K&N's. Less restriction to flow. The oil is supposed to catch the junk. It sometimes doesn't.

I beg to differ ...

Congratz on the new job. Now U can get that 450hp monster finished.
is there such a thing as MFI for 4cyl?

I remember what happened last time somebody asked that question...

He got clubbed like a baby seal?

The BMW 2002 tii ran MFI.

Yeah, pretty much. Although I thought that the original question was a valid question, asked in a respectful manner, and deserved an on-topic reply.

yep, and IIRC he was a new member that hasn't re-surfaced... imagine that... first impressions DO matter

some beetles also had a MFI, that would probably be easier to adapt to our 4s, but IIRC, THAT MFI was craptacular.

I think a good MFI setup could be really cool on our 4cyl engines... maybe easier to understand and tune than other EFI systems, but perhaps a little better performance and drivability than webers. problem is, other than the MFI for 6s, I don't know of a GOOD MFI.

I have the stock fuel filter console and filter for the MFI, but it won't work with carbs.

As for MFI on a 4, the only one out there is the MFI for the BMW 2002tii, and the pumps for those are even more expensive than the 911 pumps. It could be done, but it would be a killer.

It will be 1500.00 to get my pump rebuilt. Until then, I am stuck with the carbs....


And Capt'n.... do you have an factory air filter assembly for the 2.2L Mag stack MFI setup that will fit under a 914 engine lid? I actually bought the K&N filters to use on the mag stacks because I couldn't get my factory air filter to fit under the engine lid.
The 2.4T plastic stacks and stock filter would fit, but just barely....

Yes it will. You just need to plug some holes temporarily. Remove the following and plug the openings with an appropriate metric straight-thread plug and crush washer.

* Cold start solenoid on top of the fuel filter console.
* Return from the MFI pump (the banjo nearest the rear of the car).
* Return to the fuel tank. This is the center (straight) fitting on the console and regulates the pressure for the MFI system.

The supply from your pump goes to the banjo toward the front of the car. The filtered fuel to your carbs comes out the bottom of the filter canister.

Love Gus' work but you're overpaying by neary $1,000.00, especially for something as simple as this.

I think your problem with the cars would be the 135mm venturi's
you must have NO low end on that sucker...
do you use a seperate coffee can sized throat on each barrel?