K75 injectors.

[mjydrafter]

I have been researching a bit about injectors.  I'm hoping to get a bit of "peer review". :yes

My 4 wheeled vehicle is a Jeep Cherokee with the 4.0l.  One of the popular mods is to replace the old EV1 injectors with newer EV6 injectors off of a Dodge Neon.

The original injectors on the Cherokee and the K75 are the old type EV1 injectors, this is their only similarity as the Jeep injectors flow a lot of fuel compared to the K75's injectors.

The EV1 injector is a 2 piece body, apparently prone to leaks, and the injector end is 1 hole or pintle.  If you saw one going it looks like a single stream of fuel coming out of the injector.  The EV6 design is more modern 1 piece, and should be more efficient due to them having 4 holes or pintles at the injector tip, they have 4 streams of fuel coming out of the tip.  Better fuel atomization should result in better mileage and quicker starts.  If nothing else the EV6 injectors are much newer.

They are both manufactured by Bosch as well as the replacement Dodge Neon injectors.  Bosch injectors can be identified by one of the numbers on the side of the injector, for instance the stock K75 injectors are 0-280-150-210.  Searching this number will take you to a number sites with the flow information on this injector and many others.

This site is where I have been getting my information from: http://www.witchhunter.com/injectordata1.php4

You'll note on that page that you can click on any of the number listed for a pic and that particular injectors flow rate and resistance.  You can for instance look at the K75's injector 0-280-150-210 and see that it flows 152cc's at 16 ohm's.  (Note all injectors tested at this site are tested @3bar so that you can compare the flow of each at the same pressure).

Simple enough, now we just need to find a common injector that has a similar flow.  I did that for us.  If you look at 0-280-155-962 you will see that it is the newer EV6 style injector that flows 154cc's at 14.7 ohm's.  This injector can be found on '98-00 Ford & Mazda trucks with 4.0l v6. 

I went to the junkyard yesterday and pulled a set, incidentally the only set at my junkyard... Also it is not as easy as pulling the rail on the K75, so plan accordingly.

The only downside I can see is that the Ford injectors don't have the slit cut at the top for the spring clips that hold the K75 injectors to the fuel rail, these are not really needed as the fuel rail is bolted down clamping the injectors in between the intakes and the fuel rail.  The flow rate should be really close, if nothing else just a touch richer. 

Can anybody think of a reason that these won't work?  Anything that I am missing?

[Rick G]

I have never been to the "dark side" of injectors if there is one but I cant see why they wouldn't work just fine.

[branandfox]

Ordered some new Fuel line and these beautys:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200768183180#ht_1572wt_976

Ill post pics of changing out the lines and injectors soon!

P.S: There is another set for sale here:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200767009136#ht_1571wt_976

Same Injectors. If your looking to have yours serviced maybe its time to upgrade?

Above is my original post of buying the 4 Hole units. Further in the " what did you do to your motobrick today" thread is my posting showing me changing them and my Update as to how they run, And below is ducks recommendation.

Yeah shooter, that be them! Duck actually just installed some as-well so if you want a second opinion of them then hes got it! more torque, Maybe a little bit of a smoother engine, and Better MPG! Its a Great upgrade!

Ducks Review Below.

Butt Dyno definitely approves.  :2thumbup: When I went from a 32:10 K75 monolever to a 32:11 paralever final drive it seemed a little luggish in low RPMs in first.  That's pretty much gone now and it seems to have better torque through the whole range.  As for smoothness, that's pretty hard to tell since the K75 is so smooth in the first place.

Five Motobirds!

 :mbird :mbird :mbird :mbird :mbird

     PS! Im not sure the difference in the K1100 and K100 Versions of the bosch injectors, If you have a K100 there are K100 plug and play models by Osidetiger somewhere floating around. Just make sure they are compatible!  :hmm:

Oh did I mention they are sexy aswell? Because they are!

I'm not sure how the ford units will affect the bike without the clip, as far as I know the clip keeps it from coming loose from the rail and keeps the system pressurized. I don't know If the vibration from the bike is enough to unrattle the injectors, especially on the 75. On my 85 K100 I wouldn't test it! But the injectors do work much better.

[motodude]

According to RealOEM, the ealry (up to '89) K100 injectors have the same part number as the K75 injectors (which did not change up to '95).

What am I missing?  Is there any reason why these 4-hole injectors would not work on a K75?

Thanks,
Tom

[branandfox]

the units should work with a 75 if they had the same injectors as the early 100's.

[argent brick]

Anything for better MPG!

Was that up to 1995 or through 1995 for the k75?

[branandfox]

not sure, But I know as long as it uses the K100 EV1 injectors you can use the 4 hole bosch type 2's. I got mine from Osidetiger in the link I posted. I am unfamiliar with the 75's though so I'm not sure when the injectors changed for them. I would say these injectors would work up to 95 though. alot of things of alot of models changed that year.

[wmax351]

The links you posted are 17 pound injectors. The 2valve k bikes use 14 pound ones, at a lower pressure. Those will give you a rich mixture. For quick throttle roll ons, that will give you better response, at the expense of gas mileage, as the L-jet ECU only controls mixture by airflow, and has a slight lag with quick throttle openings.

[mjydrafter]

The links you posted are 17 pound injectors. The 2valve k bikes use 14 pound ones, at a lower pressure. Those will give you a rich mixture. For quick throttle roll ons, that will give you better response, at the expense of gas mileage, as the L-jet ECU only controls mixture by airflow, and has a slight lag with quick throttle openings.

Is this in reference to branandfox's reply with the ebay links?  Interestingly the other numbers listed on the auctions list the 0-280-150-210 injectors as a cross reference, even though the auction is for the heavier 17lb injectors.

The injectors I have found should be very close to the originals at 14lb, I didn't want to go too big as like you said the K75 is kind of a "dumb" computer... I think on more modern vehicles you could use "different" injectors as the computers would adjust the injectors based on a lot more parameters than just the airflow.

The only difference seems to be the ohm rating, but they both fall in the range for high impedence, 12-16 ohms.  (original K75 = 16 ohm, ford injector = 14.7 ohm)

Any idea if there will be a problem based on the difference in impedence?

I hoping not, since the injector controls are "dumb", so it just needs "some" resistance to fire the injector. 1.3 ohm doesn't seem like that big of a deal, but computers aren't known for their flexibility. :giggles

Thanks for the other replies guys, I was hoping to get this kind of discussion going. :yes

[mjydrafter]

This link has some info in the other k-bike injectors and their flow ratings: http://www.euromotoelectrics.com/category-s/43.htm

Interestingly it lists the K75 injectors at 161cc's.

[Rick G]

With regard to the different impedance I think you would only be looking at .2-.3 Milliseconds quicker to open (thats if I am remembering my theory from 45 years ago correctly) so in theory it will be different but in practice virtualy the same.
On the subject of flor rate I seem to remember that the K100 injectors on an L-Jetronic system were 135 and the K1100 or Motronic were 161. I may be wrong but I cant see why the K75 would be different. The problem here is that I see so many figures thrown around and I am crap at finding old posts.
A Bit later Looks like I am wrong about 135 but even reading the EME site there seems to be some conflicting info some reads like the 16v came out in 1985.

[motodude]

Anything for better MPG!

Was that up to 1995 or through 1995 for the k75?

What I saw on RealOEM was the part number was the same through the end of the K75 run (through 1995).

There has been a lot of information (impedance, etc) thrown around on this thread.  Little of it I understand (I grew up on carbs), but I do appreciate as I learn stuff. 

It seems to me that if the part number is the same as the _early_ K100s.  Then a 4-hole injector that fits a _early_ K100 should work in a K75.  What am I missing?

Tom

[mjydrafter]

The k100 injectors should be the same as the k75, just one extra.  Since each of the cylinders are identical in displacement, injectors for one should be the same for the other.

I wish the euromotoelectrics site listed the actual Bosch part numbers.

When I started looking for these I was looking for something inexpensive and easily accessible at the local junkyard.  Some that weren't as costly as the refurbished injectors, and more plentiful than Motorcycle injectors.  It would be nice to have something else that would work in a jam.  I also wanted the newer EV6 injector vs. the two piece EV1s.   

I don't have any Motorcycle junkyards around here.  So even if I wanted to get the originals refurbished I would have a lot of downtime, sending them to Mr. Injector or anywhere else for that matter.

Other than the part numbers, flow numbers, and impedence numbers, injectors are pretty simple creatures...

I have a homemade injector cleaning station.  So, testing, cleaning and comparing the injectors is pretty easy.  I could even rig up a flow test, but most of the info I have found has stated if the injectors are clean their flow rates should be really close.

[wmax351]

Some of it has to do with pressure. The motronic system uses a full 3bar, unlike the 2.5 of the jetronic

[motodude]

Thanks for all the information, mjydrafter & wmax351.  It is very helpful.  And, by _early_ K100 I'm referring to the L-jetronic.

I'll look around for some as this sounds like an excellent upgrade on several levels.

Thanks again,
Tom

[branandfox]

Hmm I didn't think about the 75's having a different computer, Im guessing you couldnt take a Jetronic and mod it for the 75? or mod the 75's computer? if its even worth messing with, I'm not sure how much the different computers would change the injection system. It is a older system, I would worry more if it was a newer system in a newer bike.

[wmax351]

Hmm I didn't think about the 75's having a different computer, Im guessing you couldnt take a Jetronic and mod it for the 75? or mod the 75's computer? if its even worth messing with, I'm not sure how much the different computers would change the injection system. It is a older system, I would worry more if it was a newer system in a newer bike.

The K75 and k100 computers are very similar (identical in hardware) but with a different fuel map burned to them.


In regard to upgrading the fuel injection system, I am planning to set up a megasquirt or VEMS system, that is a custom, modern fuel system. I will have a wideband oxygen sensor, allowing closed loop control of fuel mixture.

[mjydrafter]

With regard to the different impedance I think you would only be looking at .2-.3 Milliseconds quicker to open (thats if I am remembering my theory from 45 years ago correctly) so in theory it will be different but in practice virtualy the same.

This is good info.  I can't find any reference online about the differences in impedence within the high impedence group of injectors (most sources list the high impedence injectors at 10-16 ohm's).  Most of the info I can find is just high impedence (10-16) vs. low (1.5 - 4.0), which is not of much use as we are only interested in the high impedence injectors.

So short of me just manning up and trying these out they shouldn't cause any huge problems with the computer? :dunno2:
And the difference in impedence seems to be a matter of the injector firing "just a bit sooner" than the originals?


And just for the record, I'm getting a decent 39-40 mpg and I'm not having any issues that lead me to believe that my injectors are not working properly.  So I really don't want to cause any headaches for myself or my lovely brick. :loco: :yes

[frankenduck]

Some of it has to do with pressure. The motronic system uses a full 3bar, unlike the 2.5 of the jetronic

K1100s operate at 2.5 bar.

[WayneDW]

[/quote]


And just for the record, I'm getting a decent 39-40 mpg and I'm not having any issues that lead me to believe that my injectors are not working properly.  So I really don't want to cause any headaches for myself or my lovely brick. :loco: :yes
[/quote]

Actually, depending upon how quick off the line you are, a K75 should be getting around 50mpg  (at least mine does).

[mjydrafter]

A quick update.

The brick does not like these injectors, for whatever reason.  I had flat spots in acceleration and just general fuel related drive-ability issues. 

I cleaned the originals and put them back on.  All back to running normal now.

[frankenduck]

A quick update.

The brick does not like these injectors, for whatever reason.  I had flat spots in acceleration and just general fuel related drive-ability issues. 

I cleaned the originals and put them back on.  All back to running normal now.

What injectors did you use?  I installed the Fleabay green and silver ones and they really helped my K75. (vs. stock injectors professionally cleaned about 900 miles ago)

Did you synch your throttle bodies after installing them?

[wmax351]

Hmm. I looked at the fleabay ones. Those are 17 pound injectors. Seems like it would richen the mixture significantly.


http://www.ebay.com/itm/BMW-K100-Motorcycle-Reconditioned-Fuel-Injectors-/360457815791?pt=Motorcycles_Parts_Accessories&hash=item53ecf5c6ef&vxp=mtr

I have these in mine. Work pretty well.

Keep in mind, much of the engineering takes into account the fuel injectors. For example, one of the formula SAE teams I talked with, who also had nearly the most power and best fuel economy of any team, used the simple, single hole pintle injectors. Directed the spray directly onto the valves. The heat vaporizes the fuel.

[frankenduck]

It sure doesn't ride like it's running rich, just noticably more oomph and smoother at low RPMs.

[mjydrafter]

What injectors did you use?  I installed the Fleabay green and silver ones and they really helped my K75. (vs. stock injectors professionally cleaned about 900 miles ago)

Did you synch your throttle bodies after installing them?

I was trying out the Bosch 0-280-155-962.  They are a 14lb injector off of 98-00 ford 4.0l v6's.  They are the newer style ev6 injector, with a 4 hole pintle.