Inside a Bosch Fuel Distributor

Nice picts.
Are you going to replace all (some) of those little thingies?
Is there a kit available?

Thanks

 

308 GTS,Thanks for showing the k-jet dist head,but try to put all these components on a nice clean bench,the workshop floor is far to dirty,


cheers
Dale.

 

Good job, going where others (including myself) fear to go. The center piston on my fuel distributor is stuck, so I went to the local Bosch rep, who said it was unwise to open it up because they were sealed at the factory and never worked properly when put back together. But looking at the parts, it looks pretty straightforward, so I think I'll open mine up. However, have you sourced the gaskets and springs? Or do you plan on cutting your own gasket?
Tom

 

Some time back I took one apart from an Audi, I had a devil of a job getting it back together but once done it worked fine. As I recall there are "o" rings that are a real pain. Good luck on rebuild.

 

When I count the pieces, you allready loose some parts...or did they break when coming of ?
Guido

 

When Bosch service a distributor head the do so in "laboratory " type conditions and they are also pressure tested for leaks, so be very careful when re-building your metering head.

Replace all seals and torque the the metering head down to the correct torque (sorry I don't have that figure, but could find it if you haven't got it)
Remember the fuel pressure that passes through the head is 5.2 bar /
75.5 psi.


MW

 

Maybe a dumb question, but how does it work? I know with EFI, the whole system is pressurized, and the injectors have wires attached to them which a computer sends a signal to in order to open the the injector for the proper duration at the exact time. With a fixed amount of pressure via a pressure regulator and a fixed size of orfice in the injector, the flow rate is a constant and the timing and duration are varied.

But how does K jetronic work? As I undestand it, all the injectors are open, but that thing somwhow knows when to send a specific amount of fuel to a specific injector at a specific time? How? As I understand it, the injectors don't open and close, they are just spray nozzles waiting for fuel pressure...

 

There's no "when" with K-Jetronic (a.k.a. CIS = "Continuous Injection System")

Do an internet search on "Bosch K-Jetronic"...IIRC there are some good Volvo sites covering K-Jet theory of operation.

 

Here is a great site:

http://www.auto-solve.com/mech_inj.htm

 

A FD may look simple when you see the parts inside, but you can't calabrate it and if you saw the actual flows at idle and low speed you would undedstand. I am in the business of rebuilding fuel distributors. It is a complex procedure to rebuild one right and to ensure it works properly on the car. I have had many mechanics and shop owners come by and see how it is done. It is not a secret I will show you what it takes, but you will figure like the others that you don't have the time or money to build the proper tooling to save $500 or less. Also anyone that thinks they can rebuild one properly bring it down and I can measure the flow to see if it is within spec. Bosch has a 10% flow allowance spec and I have a 3% allowance. Tell me what yours flows and the difference from one port to the next at idle. Spec is 5 CC per min at idle. Face it this is not a bench job or the parts would be avalible, somwhere?
Thank you
Larry Fletcher
CIS Flow Tech Llc.
251-929-3771

 

I just saw the pics that is a 0 438 101 018 Or a 0 438 101 016 off of a mercedes 420 / 560 Or early '90s 500 its nothing like whats on the 308s. The TR's have two 6 cyl versions of this one. It is the most difficult one to rebuild.
Larry Fletcher

 

Hello Larry,
Can you give some more insight as to what is included in a rebuild. I would seriously consider sending you mine this winter just to have a "tune up" done to check flow etc. I just replaced a injector that may have been causing me plug fouling and was amazed at the rust and crap that was on it. So I think it is time to break down the other parts of the system and check to see if they are ok. Looking forward to your input.
Thanks
David S.

 

I am not sure I completely agree. I have seen fuel distributors rebuilt with no ill effects. If you use the correct diaphram and keep all of the springs in their correct location, replace the oval o-rings for the plunger and so on it should be fine. A friend of mine rebuilt his and his car is still running strong. This was a while ago but I can try to find out where he got the kit from.

 

You're quite right, I have "re-built" metering heads, but without a flow test bed you cannot calibrate the metering head to the specifications that it was originally set up to produce.


MW

 

my FD is out of the car and i like to know if there is a rebulit kit for it ?? or some CO that can do a good rebuilt 1980 308gtsi 2 valve

 

ria -- Give your location -- if you're in the U.S., or even N.A., why not start with Larry Fletcher?

 

i am in brunswick ohio . i am not sure on lary fletch after the fix on the boxer.

 

I know the Boxer your refering too. I have rebuilt the FD on one side of the car and later tested both FD's to ensure that they were matched. I told the owner from the beginning that both FD's should be rebuilt at the same time. I have talked with him many times teaching him test procedures on the CIS. The last time we talked he was having a air problem on one side. I told him swap the FD's from one side to the other and see if the problem moved to the other side, it did not. This owner is a very nice person, he's not a Ferrari mechanic or a CIS specialist. The car was 800 miles from me so I could not look at it myself. I don't normaly see the whole car anyway. I even located some shops near the owner that were competent to work on the car for him. Call him up and ask him about me. Or e-mail me your phone # and I will ask him to call you.

No.2
I don't like to talk about the other companies that rebuild FD's. I have several large parts dealers that dealt with the other companies and now deal with me. Some of them are very vocal about their dealings with the others. Also call the others and ask for tech support, or the owners home phone #, you have mine. Call The Bosch tech support line and ask who they recomend? I don't mean to sound arrogant. I am so busy its all I can do to keep up. I don't have much time to post these things, or fish, or anything else. I have distrubitors that have the M-B, Porsche, Delorean, and RR markets well covered. There are not many people covering this market. I don't see any other rebuilders posting anything anywhere. I only see posts from sales people. So I post things here from time to time to try to let people know that you can contact me, and that I'm not interested in rapeing you because your common FD happens to be bolted to an uncommon car.

No.3
I have posted pics of FD's apart showing the effects of fuel additives.

I have seen many things tried on FD's in the field, and many parts destroyed. Bosch does not sell any of these parts. I make them myself, have them made, or part out cores. There is a limeted supply of these things, so please don't break them or one day we may all be out of luck.
Larry Fletcher
CIS Flow Tech Llc.
251-929-3771

 

Feel uncommonly obligated to chime in here.

Spoke with Mr. Fletcher regarding my ongoing problem with 328. He was very pleasant, looked up K-Jetronic terminal readings, and was genuinely interested in what the ultimate fix.

Good character reference from me.

Carl