3B diaphragm replacement

[haryv]

There seems to be alot of discussion on the diaphram replacement. As a preventative parts replacement measure, when should these diaphragms be replaced?

I have over 400kms on my truck and do not have this issue so far. But do not want to wait until it happens. Also, is there any maintenance related issues to keep my IP running optimally? I have a 3b engine.

 

[peteinjp]

I made a separate post on this but it slipped buy so since it is related I thought I'd just add it on here.



So it looks like I'll be replacing the diaphragm in the near future. I plan on draining the oil from the pump while I'm at it. I figure I might as well give the entire injection system a good service.

In addition to pulling the injectors for testing/replacement what other areas should I plan on going over in order to get the system in good shape over the long run.

New air filter

New clear hoses- is there a reason that the hoses from the pump to the throttle need to be clear? Are they standard vinyl tubing?

New fuel filter and fuel hoses

Any particular tools I should have to get the thing in standard tune?

I'm new to working on Diesels- though I have been driving one for 5 years- the nissan patrol just keeps on going...... crossing fingers there- ha!

Edit- neglected to mention the mileage- about 165,000 km (100.000miles) on the clock. The truck has enjoyed minimal maintenance until this point- so give me the full list....



Pete

 

[lostmarbles]

lostmarbles your a wealth of knowledge on these old tojos cheers for the info you`ve added here top stuff hopefully its why me truck just started idling @ 900rpm`s , i was kind of hoping the big heap of goop i dumped out of the water trap may fix it but nup on to the diaphram cheers champs

Thanks Mudguts .... but I don't think I should personally be taking the credit for all the good info in this thread.

Good luck with your diaphragm change.

There seems to be alot of discussion on the diaphram replacement. As a preventative parts replacement measure, when should these diaphragms be replaced?
I have over 400kms on my truck and do not have this issue so far. But do not want to wait until it happens. Also, is there any maintenance related issues to keep my IP running optimally? I have a 3b engine.

"Every 120,000kms" is a figure that sticks in my head for the "diaphragm replacement interval" Haryv.

And adding a couple of drops (no more) of neatsfoot oil to the diaphragm at every oil change is a good idea along with draining engine oil (that gets through the seals) from the other side maybe every second oil change.

I made a separate post on this but it slipped buy so since it is related I thought I'd just add it on here.
So it looks like I'll be replacing the diaphragm in the near future. I plan on draining the oil from the pump while I'm at it. I figure I might as well give the entire injection system a good service.
In addition to pulling the injectors for testing/replacement what other areas should I plan on going over in order to get the system in good shape over the long run.
New air filter
New clear hoses- is there a reason that the hoses from the pump to the throttle need to be clear? Are they standard vinyl tubing?
New fuel filter and fuel hoses
Any particular tools I should have to get the thing in standard tune?
I'm new to working on Diesels- though I have been driving one for 5 years- the nissan patrol just keeps on going...... crossing fingers there- ha!
Edit- neglected to mention the mileage- about 165,000 km (100.000miles) on the clock. The truck has enjoyed minimal maintenance until this point- so give me the full list....
Pete

Gee that's a low mileage Pete! I'm envious.

People fit clear fuel hoses so they can see the state of the fuel passing through. (For example they may be keen to see if there are air bubbles present.) But as far as I'm aware the factory never did so. And I'm not a fan of clear fuel hoses myself because my experience is that the clear plastic doesn't stand up well to the fuel. (I find it becomes opaque and stiff over a relatively short period of time.)

I use "black marine fuel hose" which lasts as good as the OEM black "rubber" hoses.

Your list sounds good (with regards to maintenance) and the FSM and Owner's Manaual are excellent guides on this subject.

And I think the best thing to do with tools is simply buy whatever you need to do each particular job well. For instance you'll probably need to buy two different "filter removal tools" ... one for the smaller dia fuel filter and another for the larger oil filter. And you want ones that work well in very confined spaces.

If I tried to make a tool list I'm sure I'd leave important stuff out.

I've got virtually every tool I ever need now (cos I'm old ) but it has taken a lifetime to accumulate that. And over that period I've regularly replaced tools when better ones have caught my eye.

It takes experience to know which are the best tools to buy and I think the best thing to do is just get stuck into the work and learn for yourself.

(The only way you can really seek advice to avoid mistakes is to ask opinions on specific tools.)

 

[peteinjp]

Thanks Tom,

As for the hoses- its not the fuel lines that are clear- but the lines that go from back and forth to the throttle body from the IP. Just wondering what the reasoning is. Or if it can be replaced with regular fuel hose.

Pete

 

[Falco80]

Thanks Tom,

As for the hoses- its not the fuel lines that are clear- but the lines that go from back and forth to the throttle body from the IP. Just wondering what the reasoning is. Or if it can be replaced with regular fuel hose.

Pete

Pete, those hoses have to withstand vacuum, so i doubt normal fuel hose would work. The standard hoses have a metal spiral inside so the hose cannot collapse. I don't see why you couldn't use a similairly constructed hose though...

 

[RufusTheDufus]

Hydraulic suction hose would be OK if you have access to it. It's reinforced with a steel wire.

 

[lostmarbles]

.... its not the fuel lines that are clear- but the lines that go from back and forth to the throttle body from the IP. Just wondering what the reasoning is. Or if it can be replaced with regular fuel hose. ....Pete

Pete, those hoses have to withstand vacuum, so i doubt normal fuel hose would work. The standard hoses have a metal spiral inside so the hose cannot collapse. I don't see why you couldn't use a similairly constructed hose though...

Hydraulic suction hose would be OK if you have access to it. It's reinforced with a steel wire.

Sorry for misreading your post Pete (and I agree with what Dan & Rufus have said).

I'm still running the original spiral-reinforced clear hoses there (although they have yellowed considerably now.)

I think this type of reinforced plastic hose would work:





These photos are from one of my motorbikes (an old Brittish one where I feel I REALLY need to see the fuel despite the drawbacks of using plastic).

 

[peteinjp]

Just a little follow-up. I got in touch with nippon desno and they recommended a local dealer/diesel repair shop. I ordered the denso number 090 580 0041 and it costs less that $20 US. 1,760yen. And they are going to drive it over to my house as soon as it comes in.... Japanese service can be so good sometimes!

They stated that after the diaphragm replacement the pump should be tuned again. Any thoughts on that note?


Pete

 

[lostmarbles]

....They stated that after the diaphragm replacement the pump should be tuned again. Any thoughts on that note? ....
Pete

I can't see why replacing a diaphragm should automatically make any other work necessary.

Perhaps they are suggesting the time interval for "diaphragm replacement" is the same as for "IP overhaul/recallibration" .... but I don't think that's true either.

I suggest you just ignore that bit of advice.

 

[peteinjp]

Well I figure I'll give it a shot and see how it affects things. Looking thru the 2b manual the specs for the pump are quite specific and are supposed to be carried out on a testing stand. With only 170,000km on the clock I think I'll be ok for now. They said they can test and tune the pump for $500 or so. I think I can wait at that price as the truck runs well as it is now. I'll pop in the new diaphragm and take it down that way and have them simply check the exhaust and see what kind of results I get.

The b/2b manual calls for grease where the diaphragm seats against the housing- but at another point it states "Do not allow any grease or oil to get on the diaphragm." What's the deal with that?



Best!
Pete

 

[cruiser_guy]

They stated that after the diaphragm replacement the pump should be tuned again. Any thoughts on that note?

Don't waste your money, or if you really need to I'll PM you my address and you can send some $$ my way!!

 

[lostmarbles]

The b/2b manual calls for grease where the diaphragm seats against the housing- but at another point it states "Do not allow any grease or oil to get on the diaphragm." What's the deal with that?....Best!...Pete

The diaphragm is made of leather and so engine oils and standard lube greases will damage it. (Only "Neatsfoot Oil" should be used to keep it soft.)

But a light smearing of grease on the housing joint faces won't even get on the diaphragm if you're careful.

(And even if you don't apply any grease at all - I doubt you'd have a problem because that joint doesn't need to be 100% airtight IMO. .... 99% airtight would still work perfectly as far as I can see!)

 

[peteinjp]

Just an update and a few hints for this process. The whole job took 2 hours and I could do it in much less time if I did it again. This was with the engine in the truck and it really wasn't too hard with the EDIC removed. I pulled the cotter instead of taking off the nut and had a snag there. The cotter pin broke into 3 pieces. Both it and the washer were worn from vibration.

Thinking that if I dropped anything I would be screwed I very carefully removed the pieces without dropping any. A pair of 90deg needle nose pliers are very useful. I also used a fine pair of needle nose pliers from Peak. I thought that if I dropped something that it would end up in the inner workings of the pump however upon getting the diaphragm out I found that there is really no where for the bits to go that will do any damage.

Sure enough the IUD was shot. There was plenty of oil on either side of the diaphragm and it was caked on to the housing indicating that it had leaked over a long period of time. I'm sure that the excess oil contributed to the failure- however after being in use for 30 years I'm sure that it would soon parish from use anyway. On that note I could not find any hole for lubricating the diaphragm as Tom mentioned on my 2b.

The replacement cotter was 5/16 stainless- I recommend steel in case you do drop it so you can fish it out with ease with a magnet. The hardest part was bending the cotter- not much room to get in there and its very hard to see. I cut the short side of the cotter even shorter and placed it in with the long side facing me so I could reach in with my pinky and bend it.

I lightly greased either mating surface of the diaphragm's metal casing as the factory manual calls for. Put 2 of the bolts in your mouth when putting the housing back in place in case you drop one. Lining up the IUD with the slot in the pump is a bit tricky. After putting the spring and housing in place you can turn/wiggle it back and forth a bit and watch the diaphragm casing to see if its turns. As you turn you can feel if the tab is seated in the notch thought it is very subtle. Make sure the spring is located properly in the back of the diaphragm as well.

Shorty flat head for the housing and a long extension with a 10mm socket for the EDIC and your good to go. Grease the edic pivot while your in there.

Driving I immediately noticed a night and day difference. I can't say that it is much more powerful at WOT but there is a very big difference in terms of pull with slight throttle input. I have to get used to is when i change gears. No more high idle and much less throttle input required for acceleration. It is so much better! In terms of the shop that recommended that I have the truck tuned with the new diaphragm I'd have to say that while it may help it would never improve the performance nearly as much as the diaphragm replacement itself.

I'd say this is a good thing to do on any cruiser over 20 years old without a doubt. The only thing I would do differently is I would have a set of replacement vacuum hoses go in at the same time because a leak there would cause the same issues. Also a new oil plug seal is good to have on hand. So I'll be getting a new set of hoses and a a handful of seals on the way. And you can bet I'll be draining that oil plug with each future oil change.

Thanks for all the good info in this thread!

Pete

 

[lostmarbles]

.... On that note I could not find any hole for lubricating the diaphragm as Tom mentioned on my 2b. ..
Pete

Hi Pete. Glad your replacement went well and had such a beneficial effect.

How about a photo of your IP directed at the area where my plug is (for adding drops of Neatsfoot oil to the diaphragm)?

I'm sure you must have something there for the same purpose.



Edit a few hours later .... Here's a pic of a B with the plug arrowed:

 

[peteinjp]

Tom, I'll get a pic of it- but I'm not sure exactly where I should be taking a pic of? Near the drain plug?

Pete

 

[cruisedeisel]

dudes, i don't know how you guys manage to change diaphams while the engine is in the truck. wow, i tried and ended up losing the nut inside. so i just took the injector pump off. way easier, 3 hours

 

[Falco80]

dudes, i don't know how you guys manage to change diaphams while the engine is in the truck. wow, i tried and ended up losing the nut inside. so i just took the injector pump off. way easier, 3 hours

It is a fiddly job for sure, but easily acheivable with some patience. Much easier to just remove the whole EDIC motor and arm than the injector pump. I found i had room to work between the inner guard and chassis rail on my 40, so that made it easy to see everything. It's not something you would want to be replacing every week though!

 

[cruisedeisel]

dammit, well it seems that diaphram wasn't the problem. i ended up changing the whole injector pump and my truck still has high idle. the diaphram looked good????

today im changing the intake because i think i might be sucking air in somewhere?

any other ideas would be greatly appreciated, thanx

 

[peteinjp]

Check the condition of those hoses that go between the pump and the throttle body too.

pete

 

[Mudguts]

dammit, well it seems that diaphram wasn't the problem. i ended up changing the whole injector pump and my truck still has high idle. the diaphram looked good????

today im changing the intake because i think i might be sucking air in somewhere?

any other ideas would be greatly appreciated, thanx

ive just been through this in the end the fuel tank had a layer of gooey muck in the bottom of it and was on ocasion blocking the fuel pick up
i did the governor diaphram 1st didnt fix the high idle then looked further emptied water trap it was full of really bad looking slimey goo it looked like black muddy diesel then emptied fuel tank from bottom bung and felt around inside it and found 5-7mm off absolute crap on the bottom of tank so spent today pulling it out and cleaning it what a mission on a bj42 will no in a few days if that fixes my high idle it starts and idles at 650rpm after 5 mins its upto 900+rpms will let uno the outcome though a bit doubtfull it will fix the high idle but hey who knows hoping