thrashingcows

Yes those are the 9mm injectors. The injectors themselves are not specific to having an Intercooler or not. The 9mm injectors, in stock form, are what most guys upgrade their stock 7mm injectors too. So to get the same fuel delivery from a 7mm injector, you'd have to upgrade to a performance 7mm injector.

Also the Non-IC IP has bigger delivery valves, to obviously deliver more fuel to the bigger 9mm injectors.

BC847

Eh, . . . not so much. And only in lower engine rpm, or so I've read from those who've dinked with them.

FYI:

- Stock NON IC 1st gen injector (9mm): 4x.013 = 0.000531 (total cross sectional area).
- Stock IC 1st gen injector (7mm): 6x.009" = 0.000380" (total cross sectional area).

As found here: http://1stgen.org/viewtopic.php?f=4&t=1363

jimbo486

Are the nozzles identical in size to the original non i/c injectors, 4x.013 as David mentioned above?

tech-eh

strangely enough the na73x which is the bosch number for our non inter cooled injectors was registration number the prototype aircraft for the p 51 mustang it crashed after its third flight but was so good that the military ordered it based on just those three flights

BearKiller

I really appreciate this picture.

Can anyone point me in the direction of pictures showing the relationship of the O-ring to the other components so I can better envision how it all goes together ??

My 1989 injectors are factory-original and I have no reason to believe they have ever been out.

The engine fires quicker than I can let off the starter-button, idles smooth with no smoke, and runs excellent.

However, I have noticed fuel bubbling around one of the injectors and believe the O-ring is probably deteriorated.

Believe it or not, I have never yet pulled an injector on a 6BT (swapped plenty on old V-8 I-Hs, but they are no more trouble than swapping spark-plugs).

Many thanks to thrashingcows for this excellent article.

KRB

I've had mine out several times and never had to fiddle with the O-rings. I just slipped the injector in the bore and tightened down. I did lube with diesel fuel though.

j_martin

The "O-ring" on the nut is just a dust seal to keep crap out that would seize up the nut to injector mate. It doesn't hold back a fuel leak.

The injector nozzle to body joint is what's leaking. I had 2 out of 6 rebuilds from CPP do that to me.

Pulling the injectors is straight forward. I made a puller from a piece of 3/4" pipe, a bolt, a washer, and a metric lug nut which will pop out a stuck one with little effort. There's several examples of that sort of thing on this board.

Quickest and cheapest fix (if your time is worth more than $5 an hour) might be to just throw in 1 new stock injector. If there's a slight imbalance from uneven wear, you'll probably not be able to feel it.

BearKiller

Why have you had them out so much; is there a periodical maintenance procedure that I should be doing ?? Thanks.

After looking at thrashingcows' picture of him "tamping in" the O-ring sort of after the fact, I thought surely there was no way for the O-ring to be containing anything.


So, considering the fact that a five-dollar-bill looks big as a wagon-wheel to me during this administration, and time seems to be the only commodity I have right now, what are my other options for fixing this leak ??

I found the same NA73X Bosch injectors for about $57 apiece; I am assuming the NA73X is stock replacement, right ??

Is that a decent price ??

Thanks.

Bob L

"I found the same NA73X Bosch injectors for about $57 apiece; I am assuming the NA73X is stock replacement, right ??"

I am interested in purchasing also. Where did you find them at that price ?.
Are they new ?. And they are Bosch right ?.

Thank you, much appreciated.
Bob

BearKiller

Let me see how many they have before I let the cat out of the sack.......




it is a Case/I-H parts source.....

KRB

Not really BK. I had one go bad at around 100K so I swapped in Bosh 190s. Then around 165K I had a head gasket leak and R&R'd that. There's a place in Louisville that cleaned and pop checked them then for me for about $20 each so I stuck them back in. Came with new washers & spacers etc.

thrashingcows

BK...your very welcome! Glad you found the pics, and info helpful. That is why I try and post decent pics, and info....to help others.

As for your injector leaking a little....you can just try and tighten down the nut a little. It's leaking between the copper seal and the head. If that does not help then you need new copper washers. Your injectors are probably fine.

BearKiller

As strong and smooth as the engine runs, I didn't think much could be wrong.

I spent some time today experimenting and observing; what I learned is that they are NOT leaking liquid fuel; they are leaking compression.

Yesterday, when I noticed something was amiss, the area around the injectors was soaking wet with fuel from me bleeding the lines.

Last night, I degreased the engine and hosed it off.

This morning, with everything clean and dry, I could see no evidence of anything leaking.

Then, I got my trusty bottle of secret recipe tire-leak detector and, when I squirted some around the base of the injector, it would start foaming with air bubbles.

When the leak detector evaporated away, the injectors were dry as a bone.


Out of the six, I found four leakers; neither the first nor the last shown any sign of leaking, but the four in between were all leaking to variable degrees.

If a 7.50-16 tubeless tire had 75-PSI at bedtime and four little nails leaking the same amount as these injectors, it would be about half flat at breakfast-time.

I figure that, once the engine heats up and everything expands, the leaks mostly go away; at least that is my theory.


As for the copper washers, I am assuming they are under the big nuts; what is the part-number and where can I get these ??

Are the washers the same for I/C as for non-I/C ??

I figure while I am buying washers, I will get enough to do several of the engines around here and the wife's is I/C.

I was just looking on E-Bay and found several vendors selling "injector installation kits" for 1991.5-1998.5. These kits come with 18 copper washers, six each in three thicknesses. I could not find a single source for 1989-91 models.

Seeing as how the non-I/C have 9mm injectors, as opposed to the I/C having 7mm injectors, the installation kits would be different, right ??

Way up front on my list of things to do is to fabricate one of those pullers like you guys have pictured.

My plan is to cut TWO lengths of the 3/4 pipe, one a bit longer so I can get that first hidden injector; on my engine, there are about a dozen more obstacles in the way of getting it; I can sort of see it and almost touch it with a finger.

Many thanks.

BearKiller

I am not knowledgeable about the many injector names and numbers I often see in these forums.

The NA73X injectors I am assuming are original equipment for a non-I/C engine; do they have any other designation ??

What does the "190" represent on the Bosch 190s ??

Your engine is new enough to be factory I/C, right; are these 190s still 7mm, or are they 9mm ??

Then I see mention of "Pods" ; what are "Pods" ??

Please everyone excuse my ignorance and educate me.

Many thanks.

KRB

Yea, mine's intercooled so they are different.

At the time, Bosch 190s were recommended as a nice upgrade without a lot of smoke etc. Not sure what 190 stands for but as I understand it they came in Cummins for marine applications.

The injector washers are different thicknesses depending on the nozzle so the spray pattern hits where its supposed to. So I'd make sure and get the stock size which I guess any diesel or Cummins place should have, I don't have any part numbers, sorry. Then there are the little banjo washers that go on the lines held down by the banjo bolts.

I just put new washers on the lines of the injector pump on an IH 806 and instead of being copper they were plastic with a metal ring. So far they work fine - and they should at $9 each!