Looking for a good CIS fuel head

[JFairman]

Title says it all.
I'm looking for a good running 930 CIS fuel head. Or does anybody know of places other than CIS flow tech that rebuilds them?

I have a CIS flow tech 007 modified aluminum fuel head that that sprays fuel out the number 4 injector non stop if the fuel pumps are running even if the motor is off.

Below 2000 rpms the motor runs on 5 cylinders because #4 is getting too much fuel and is too rich and then above 2000 rpms it runs on all 6 like normal.
I've been told it needs new o-rings because the ethanol in the E10 gas I've been using has ruined the number 4 metering slit o-ring and it's just a matter of time before the other 5 will do the same thing.

Can't afford EFI and have no desire to go that route so I hope to fix the CIS fuel head or replace it with one that works.

[T77911S]

I have talked to larry about trading my euro fuel head for one of his rebuilt aluminimnim (007) heads without the 02 sensor. I have been told the 007 is much more reliable and that the euro head is prone to "dimpling". the metal gasket.
what has he said about rebuilding yours, if you talked to him.

I would pull it part and take a look at it, what do you have to lose.

[JFairman]

I told him whats happening and he said an o-ring has been destroyed by contaminated gasoline.
I asked him what that means and he said the ethanol in E10 pump gas has ruined the o-ring for #4 injector. The rest will soon follow.

The only o-rings I know of in these fuel heads that could do this are the 6 o-rings that are on the outer diameter of the control plunger cylinder surrounding the metering slit openings.

He wants $475 to rebuild it again... If I have to do that every 6 years I'll just sell the POS because it has to run on real gasoline with no ___ ethanol in it.. or else this happens.
CIS SUCKS.

[speednme1]

$475.00 every 6 years? That's freakin cheaper than an efi conversion. At that rate it would take over 100 years to get enough money together for an efi conversion..lol
i.e. 100 yrs \ 6 = 16.66 * $475= $7916.66....still much less than what is cost me....so $475 every 6 years is not so bad

[turbo owner]

Originally Posted by JFairman

I told him whats happening and he said an o-ring has been destroyed by contaminated gasoline.
I asked him what that means and he said the ethanol in E10 pump gas has ruined the o-ring for #4 injector. The rest will soon follow.

The only o-rings I know of in these fuel heads that could do this are the 6 o-rings that are on the outer diameter of the control plunger cylinder surrounding the metering slit openings.

He wants $475 to rebuild it again... If I have to do that every 6 years I'll just sell the POS because it has to run on real gasoline with no ___ ethanol in it.. or else this happens.
CIS SUCKS.

Ethanol fuel is what sucks, I run premium with no ethanol.

[smurfbus]

We have 93 with no more that 5% and that is what I use. IF mine starts to fail its 85 all the way with efi.

[T77911S]

on the way home I was thinking how could gas mess up one of the slits, it would have to be one of the O rings.
then I was thinking it cant be the gas. there are TOO many of these heads out there that are not going bad with the same gas.
I know the insides of the euro head but not the 007 head. o don't think its an Oring. I was thinking maybe an issue with the valve seat because I don't think and issue with the oring would only effect idle, or only one cylinder and why only one oring and what did it do to the oring.

the plunger is what determines how much fuel goes to the upper chamber. the more fuel, the more the valve seat opens. If the plunger drops all the way down/closed, there should not be any fuel to open the valve so the valve has to be defective or dirt or something is keeping it from closing. with that said my understanding of the 007 head it is suppose to be more tolerant of dirt.

has he rebuilt it already?

[T77911S]

here is what I did with mine and what I would do if I were you. the hardest part of this is setting up the injectors so you can put them all in bottles while connected to the head. I swapped all the lines around and angled them how ever I could to get the injectors in the bottles without bending the lines.

I made a shim that I could wedge between the AFM plate and the bar that goes across the top of the AFM. that way the I pushed the sensor plate down the same amount every time. then I would time how long I ran the pumps. the longer the better. I also had different shims. one to simulate idle and another for mid RPM. I ran this test several times to measure the fuel and to get consistent results.
then I would take the head apart and inspect it for what is wrong. if you can fix it, put is backl together then run the fuel tests to set the fuel flow back to where it was.

this takes a lot of time but it saves $$ and I don't know about you (you may already know this stuff), but I learned a lot.,
also, put a battery charger on the batt to keep it charged while doing this.
idle testing takes a LONG time because so little fuel comes out, but I think the fuel flow at idle is really important for a good idle. once that is set, just check WOT to make sure they are all close to each other in volume.

[T77911S]

this isn't your head but may help just to look at

[RarlyL8]

Jim I checked stock and don't have any used 007 fuel distributors. It would be best if you stayed with that style instead of the Euro head as you have already tuned for the 007 fuel flow.
I agree that something doesn't seem right about the EtOH and your symptoms. The Red Rocket ran 15 years on 10% EtOH blend. I know E85 has 50% more EtOH so 10% may not be relevant if the tipping point is somewhere between 10-15%.
Also if one of your injectors is running all of the time it must be seeing cracking pressure from the fuel head in order to do so. The slit has nothing to do with cracking pressure, only volume. I suppose increased volume under the same pressure can translate to higher pressure at the injector.

[JFairman]

Hi Brian, first thing I tried was changing the #4 injector with one of the others. I changed around several of the injectors on the #4 injector line and each one kept spraying a little fuel if the fuel pumps were running and the motor was off. That tells me it's not the injector(s), it's the fuel head.

The o-ring theory from Larry sounds a little ? to me too. He was real quick to come up with that theory when I told him what's happening.

I was thinking maybe the fuel head diaphragm sprang a leak or maybe it's dirt. I just replaced the fuel line that goes from the center tunnel line up to the accumulator about a week before this started. The fuel goes through the accumulator and fuel filter after it goes through the new fuel line and before it goes to the fuel head so the gas should be clean.

Maybe I should order one of those fuel head rebuild kits on ebay and try replacing the parts that come in it and see what happens. It's a lot less $ spent on this if it works.
Thanks for the reply.

[T77911S]

after thinking about this more you could just be too rich and that one port is slightly adjusted for too much fuel, OR it is just adjusted for too much fuel. I think the most critical place for balance is idle.
when I had an air leak I have my mixture waaay rich and the same thing was going on with mine. FP's on and some injectors would spray with engine off. I even played around with the mixture like this to see which one would spray first or which one would spray last and balance the flow like that.
(I did lots of experimenting before I sent my head off)

give your mixture a half turn CCW

he diaphragm is a good thought. if it has a tiny hole then fuel from the lower chamber would leak to the top and open the valve. not sure how it would get a hole.

check the plunger edge for any nicks.

check the fuel balance before anything else.

[JFairman]

Yeah, I have more time than money so I'll watch some you tube videos of people taking CIS fuel heads apart. You need the right torx wrench and a bench vise to hold the fuel head.
Then go slow and careful and take pics while doing it so you can put it back together right. I've seen CIS rebuild kits with the o-rings and a new diaphragm on ebay.

It ran perfect for years and just started doing this a few weeks ago. Part of the problem is I hardly ever drive it anymore. It's not fun to drive in S. Florida... No hills, no curvy roads, and too much traffic.

[Rawknees'Turbo]

Jim, people in the 911 forum with CIS cars are saying that they are adding Marine Stabils to each tankful in order to try and lesson the ethanol/water problems (you've probably already thought of this, though) - wonder if that would help preserve the fuel head o-rings?

[JFairman]

This 3.3 aluminum fuel head rebuild kit is looking good.

Porsche 911 3.3 turbo fuel metering distributor repair kit: 0438100145, 93011092300, 94411092300 - salvox

Fuel head assembly alignment pins. Not sure these are needed but would help.

http://www.ebay.com/itm/Assembly-tools-for-Bosch-Fuel-Distributor-6-Cylinders-Jetronic-W900100890606-/182166402120?hash=item2a69f6b448:g:yrQAAOSwVFlT4dg-&item=182166402120&vxp=mtr

[RarlyL8]

Give it a go Jim, you know these distributors well and have the skills. You'll also be able to determine what failed.

[JFairman]

The internet is amazing...
I found pics of a Mercedes 450 V8 aluminum fuel head diaphragm before and after living with E10 fuel for a while.
It's kinda wrinkled, swollen, and disolved looking around the chambers...


The guy also put a light behind the diaphragm and took a pic. An enlarged and cropped copy of the picture shows a hole in the diaphragm at the side of one of the chambers. I think a hole like that would do what mine is doing.
I'm guessing thats it...


Some more from Salvox.
"Porsche uses an 8 cylinder fuel distributor with 2 of the ports blocked off, Porsche decided to do this after they discovered that the 6 cylinder distributor did not deliver enough fuel.

The main reason why these units are failing is because of the introduction of ethanol into gasoline which degrades the rubber Diaphragm or membrane as its sometimes known.

All of our Diaphragms are made from a material that has been scientifically engineered to resist ethanol & other fuel additives. The smallest hole or excessive stretch in the diaphragm or membrane can cause rough idle, poor acceleration difficulty in starting, or the motor just wont run."

Turns out they're in Fort Lauderdale about an hour drive south of me... They also sell on ebay and that would probably be the easist way to order this kit:
http://www.ebay.com/itm/Bosch-Fuel-Distributor-Rebuild-Kit-for-PORSCHE-911-3-3-Turbo-0438100145-/301844846729?hash=item46475ad889:g:LjMAAOSwZjJU6Jm n&vxp=mtr

[Rawknees'Turbo]

^^^

I wonder how many diaphragms are in that condition - my bet is that many are in some stage of failing like that (like you mentioned). I know that the same goes for much of the country, but here in the DFW area, I know of nowhere that sells non-ethanol gasoline (I believe that it is now e10-e15, depending on who is selling it and if the labeling is even close to accurate). I'm talking typical retail - not race-gas vendors and so forth.

[JFairman]

We have a place here in S. Florida that sells non ethanol gasoline, race fuel, etc.
They have two local stations.. one in West Palm Beach just west of the Florida turnpike and the other around 10 miles north of me in Riviera Beach.
Port Consolidated (800) 683-5823

For a list of ethanol free gas stations in the USA.
Ethanol-free gas stations in the U.S. and Canada

[RarlyL8]

I'm liking my Euro fuel distributor a bit more now. Could be why I never had a problem in the 20 years I've been running them using 10% blended fuels.