Just replaced IP diaphragm and think i messed up?!

[Falco80]

Hey guys,

Today i replaced the diaphragm in my B diesel. It was tricky to get too even with the EDIC motor removed. They cover plate still had lockwire on it, so i assume the diaphragm i took out was original. Anyway i replaced both my fuel filters at the same time. I primed the system and when i eventually got it fired up it seemed to idle a bit lower and smoother? The trouble i have now is i have basically no throttle. I can alter revs with the throttle, but when it is under load it dies. My garage is at the top of a hill and now i can't even get back up into the garage!
What do you think i have stuffed up? The diaphragm is obviously not holding vacuum i think. One thing i did notice is i don't remember seeing a seal come out when i removed the diaphragm cover. If the cover was not sealing to the housing, then that would explain it hey? I did put it back together without a seal, but i'm 99% sure thats how it came apart! Did i just answer my own question then?

 

[Falco80]

I've just looked at my B engine manual and it says to "coat diaphragm housing and idling capsule with grease to keep vacuum chamber airtight", so thats my problem i'm sure. Why didn't i look at the manual while i was doing it?
Seems strange there is no seal to me though, just grease. What do some of you guys use, just a coating of grease or maybe some sealant/liquid gasket?

 

[amaurer]

No, this is not your problem.

A vacuum leak in the diaphragm causes HIGH rpms, not idle.

Quickly, and carefully, remove the vacuum hose leading to the diaphragm - the engine should race so replace it quickly. If the engine does race then your problem is not with the diaphragm, its with the venturi. However, if it doesn't race then you have something jamming the diaphragm (never heard of that!).

 

[Radd Cruisers]

A leaky diaphragm will cause a high idle with gobs of smoke on decel and a host of other issues.

With the engine OFF, pull one of the hoses and try sucking on it, if you get air through then you did something wrong. If it holds up fine, then something else is amiss.

I have seen people turn the idle waaaaaay down to compensate for a bad diaphragm and also people turn their fuel way down in an attempt to get rid of the smoke.


~John

 

[cruiser_guy]

I have had a bad diaphragm cause an excessively low idle as well but that was years ago so it might have been something else as well. I still had throttle response but I had to keep a little throttle to avoid stalling. The last diaphragm was high idle last fall.

 

[lostmarbles]

My words of wisdom?

I don't have any really. It's rather baffling.

I agree that the housing seal is unlikely to be the problem and that the main effect of a "functioning diaphragm" is to be able to pull the rack back (inside the injector pump) to lower the fuel in response to venturi vacuum. (And it looks like yours is doing this Dan.)

Sounds like some sort of fuel restriction ... but then you've changed your fuel filters so that's unlikely.

So maybe check that you are getting proper movement of your butterfly valve (in the intake manifold). Foot-to-the-floor should turn the butterfly wide-open (vertical).



PS. As far as what I used to seal the housing - I seem to remember using a non-setting paste that is used as a thread sealer in pipefitting. But I think if I had used nothing .... it would still have been fine.

 

[Falco80]

Thanks for the help guys. I'll try the vacuum hose soon and see what that does. I found it tricky to refit the main spring inside the housing. Maybe that is sitting crooked? I don't know, i'll try the vacuum hose first and see what that does, before getting in and taking things apart again.
One thing i did notice is there was a lot of oil coming out of the diaphragm cover when i started undoing the 4 mounting screws? I also undid the drain bolt on the side to let it all out. What does this usually mean. Is that an internal seal leaking?

 

[lostmarbles]

It's probably never had that drain plug removed before Dan... So the engine oil has probably had a lot of time to accumulate there.

Therefore I wouldn't worry about it.

That plug should be removed periodically as part of routine maintenance to avoid the level from reaching the diaphragm leather. (Some leakage through seals is normal.)

Engine oil harms leather as you no doubt already know...(Which is why Neatsfoot oil is used to keep the diaphragm soft instead.)



Edit..... Couple of things I'm puzzled about....
1. You say that because lockwire was present you assume the diaphragm was original. Yet as far as I can see, you don't need to undo anything that is lockwired in order to replace a diaphragm.
2. One of your photos shows that you even removed the lever off the shaft on your IP when all you really needed to do was unclip a balljoint in the connecting rod (if you wanted to remove the EDIC motor to gain better access).

Sounds like you may have dismantled a bit more than was necessary to change the diaphragm Dan .... giving rise to more possibilities for reassembly errors.

 

[Falco80]

It's probably never had that drain plug removed before Dan... So the engine oil has probably had a lot of time to accumulate there.

Therefore I wouldn't worry about it.

That plug should be removed periodically as part of routine maintenance to avoid the level from reaching the diaphragm leather. (Some leakage through seals is normal.)

Engine oil harms leather as you no doubt already know...(Which is why Neatsfoot oil is used to keep the diaphragm soft instead.)

Hi Tom, yeah i have removed that drain bolt before, probably about 12 months ago. I saw that thread of yours "first oid drain in 30 years" i think it was called. Thats why i asked, because it seemed to have a fair bit of oil in there. I'm just wondering if that was normal or not. Where does the oil come from anyway?

I'll show you my new favourite toy too. I bought this inspection light from the US off ebay and it was damn handy when doing this job. A great addition to any 40 i reckon!

 

[lostmarbles]

You're obviously obsessed Dan. I know because I bought one of those lamps too ... and it is hard to justify what with the exchange rate and shipping costs.

(Much cheaper than buying from Toyota in this part of the world ... all the same.)

They put out a lot of light and take the same bulbs as used elsewhere on the cruiser. And you can get them into very tight places too. So that surely justifies the expenditure.

(We won't mention the truth ...... which is more like ....."I had the socket in my glovebox so I just had to have the inspection light that plugs into it ... no matter the cost!".)

BTW ... I edited other stuff into my last post.

And your engine looks really nice and clean!

It is raining non-stop over here these days .... but if there's a break in it shortly I'll undo my plug and see what comes out. (It must be at least 12 months since I've done it.)



Edit: Well I still wouldn't worry about the oil. Mine seems to have quite a bit in it too.



Actually the oil is slow to come out ...so it pays to go away and do something else while you leave it draining. (Poking a knitting needle in and out helped a bit .. but extending the drain time was better.)

 

[Falco80]

Ok, i've just had it running finally and it is a bit better than yesterday. I made it up the driveway (woo-hoo), but it still does not have full power. I sucked on the vacuum hose and can confirm it holds vacuum. I also took that hose off a couple of times while the engine was idling and can confirm the revs increase pretty quickly until i reconnect it.
Could it be a fuel supply issue? I changed both my fuel filters and primed it at the injection pump and the main fuel filter bleed screw.
It's got me stumped. It's like something is stopping the rack from moving to full fuel position. Looking at the tailpipe while the throttle was flat to the floor and there was no black smoke clouds from overfuelling.
Does any one have anymore ideas??
Thanks in advance...

 

[amaurer]

Ok, i've just had it running finally and it is a bit better than yesterday. I made it up the driveway (woo-hoo), but it still does not have full power. I sucked on the vacuum hose and can confirm it holds vacuum. I also took that hose off a couple of times while the engine was idling and can confirm the revs increase pretty quickly until i reconnect it.
Could it be a fuel supply issue? I changed both my fuel filters and primed it at the injection pump and the main fuel filter bleed screw.
It's got me stumped. It's like something is stopping the rack from moving to full fuel position. Looking at the tailpipe while the throttle was flat to the floor and there was no black smoke clouds from overfuelling.
Does any one have anymore ideas??
Thanks in advance...

If it revs up quickly with the hose off, but doesn't rev up quickly with the pedal (in neutral) then you have a venturi problem. Check the linkage.

 

[lostmarbles]

I change mine with my EDIC rod and motor etc still in place which means my IP lever is held in the "fuel shut off" position Dan.

I've never tried doing it the way you appear to have done (with the IP lever in the "motor run" position).

Perhaps your method makes it harder to connect the new diaphragm to the rack and perhaps something associated with this is now stopping the rack from moving towards "full fuel/overinject" (under the influence of the diaphragm)?

Does it start with a good puff of black smoke to show it is starting in the "overinject" position?

 

[Falco80]

I change mine with my EDIC rod and motor etc still in place which means my IP lever is held in the "fuel shut off" position Dan.

I've never tried doing it the way you appear to have done (with the IP lever in the "motor run" position).

Perhaps your method makes it harder to connect the new diaphragm to the rack and perhaps something associated with this is now stopping the rack from moving towards "full fuel/overinject" (under the influence of the diaphragm)?

Does it start with a good puff of black smoke to show it is starting in the "overinject" position?

Hi Tom, I'm thinking the way i took the EDIC arm off might have something to do with it. I played around with the EDIC today and can confirm it moves correctly to all 3 positions. The shaft coming out of the top of the IP, that the EDIC arm connects too, has a small key fitted to it so that the EDIC arm attachment can only fit one way. There's no way that the arm could have been attached to the shaft 360 degrees out is there??
What about if the old diaphragm was worn and stretched and this one is new and tight, so it doesn't allow as much movement of the rack? Is that even possible.

Ok, here's a quick breakdown...
When the engine is cold it is a lot harder to start than before. I need a lot more "clicks" of the hand throttle and a lot more cranking now than i use to to get it fire up and hold idle. The glow system is ok. After a cold start, and while it's on the hand throttle, the engine speed seems a bit erratic like it has a fuel supply issue. When it is up to running temperature it appears to re-start fine just like it used to and it idles great. The engine will happily rev, but when it is in gear and under load (like going up any slight hill) it just dies. It's like something is stopping the throttle/fuel supply. I took the inlet hose off and i have full movement of the butterfly and the two vacuum hoses are connected properly.

What about a fuel issue? Should i try bleeding the system at the injectors maybe? I've been driving around backstreets for about an hour now and figured if there was any air in the system it would long be gone. I knew i should have left the filters and changed them later once i finished the diaphragm, to make fault-finding easier in case i stuffed something up!

Thanks again!

 

[lostmarbles]

I don't think air is your problem Dan .... but regardless of this, I think you should eliminate this possibility first (simply because it is so easy to do). So with your engine running, crack the bleed nipples one at a time and then crack open the nuts on the top of each injector in turn too. (No need to bother using the hand primer at all if the engine can run.) Then go for a test drive .... (whereupon I expect you to find your engine remains just as lethargic but at least you can be more certain that air contamination is not your culprit).

As far as that IP lever is concerned ..... With the rod removed It should sit in the "motor run" position. And pushing it forward against spring pressure gets you to the "engine-stop/fuel-shutoff position" while pushing it backward (against spring pressure again) gets you to the "overinject/start position". Does it sit correctly in all the positions? (The movement angles are provided in the FSM.)

I doubt the lever can be fitted wrong (from what you say).

As far as my best guess at what's wrong? Well I'm drawn to this statement of yours ....."I found it tricky to refit the main spring within the housing". Perhaps something wasn't sitting correctly when you fitted it .... so perhaps you should open it up again and have a looksee.

I pretty sure I've always left my spring alone when I've changed my diaphragms. (Ie. I believe I've left all that stuff in the "rear nose" undisturbed.)



PS. IMO - Replacing a diaphragm should only result in improved performance and never reduced performance.

The new diaphragm should be softer than your old one and thus actually work better. But having said this, I replace mine 2 or 3 times as part of routine maintenance (rather than to correct a problem) and I've never noticed any difference in performance as a result of any of those replacements.

PPS. I have a spare engine and could probably open up that area of the IP if you need photos. Although it is somewhat awkward to get at that side of the motor at present in my cramped garage.

And I can supply pics from the FSM to help if you need that.

 

[Falco80]

I don't think air is your problem Dan .... but regardless of this, I think you should eliminate this possibility first (simply because it is so easy to do). So with your engine running, crack the bleed nipples one at a time and then crack open the nuts on the top of each injector in turn too. (No need to bother using the hand primer at all if the engine can run.) Then go for a test drive .... (whereupon I expect you to find your engine remains just as lethargic but at least you can be more certain that air contamination is not your culprit).

As far as that IP lever is concerned ..... With the rod removed It should sit in the "motor run" position. And pushing it forward against spring pressure gets you to the "engine-stop/fuel-shutoff position" while pushing it backward (against spring pressure again) gets you to the "overinject/start position". Does it sit correctly in all the positions? (The movement angles are provided in the FSM.)

I doubt the lever can be fitted wrong (from what you say).

As far as my best guess at what's wrong? Well I'm drawn to this statement of yours ....."I found it tricky to refit the main spring within the housing". Perhaps something wasn't sitting correctly when you fitted it .... so perhaps you should open it up again and have a looksee.

I pretty sure I've always left my spring alone when I've changed my diaphragms. (Ie. I believe I've left all that stuff in the "rear nose" undisturbed.)



PS. IMO - Replacing a diaphragm should only result in improved performance and never reduced performance.

The new diaphragm should be softer than your old one and thus actually work better. But having said this, I replace mine 2 or 3 times as part of routine maintenance (rather than to correct a problem) and I've never noticed any difference in performance as a result of any of those replacements.

PPS. I have a spare engine and could probably open up that area of the IP if you need photos. Although it is somewhat awkward to get at that side of the motor at present in my cramped garage.

And I can supply pics from the FSM to help if you need that.

Cheers for the offer of more help Tom. I do have a B/2B engine manual here and have been looking through it furiously! The IP end of the EDIC arm and the motor end are both within the marked lines when in the drive position and move correctly to the overinjection and stop positions like stated in the FSM. I had the diaphragm cover off again today to have a check and put a small amount of sealant on the cover. I made sure the spring was seated correctly when refitting it and the shim also stayed in the nosecone ok. The new diaphragm is nice and soft. I'm really a bit lost here as to why it is not running like it was. I did change this as "preventative maintenance", but i guess a lot can be said for "if it ain't broke, don't fix it" hey!? My gut feel is something is not right with the IP rack, but i'm struggling to see how or what?!

I'm flying off to work again tommorrow for another week, so the BJ can sit at home until i get back and have another look at it. I will crack the injectors then, just to rule out air trapped in the system as a possibility. Today, on a straight flat section of road i struggled to reach 50/60km/h with my foot flat to the floor, revving out 2nd gear. Frustrating. I can't drive it like it is at the moment.

 

[lostmarbles]

..."if it ain't broke, don't fix it" ...

I always shudder when I hear this quote Dan.

I'm not a believer in this attitude at all because to me it says "Don't bother with maintenance! Just wait for a breakdown!". (But I know you're joking.)

Maybe posting up some photos of your fuel supply/injection area with it all reassembled/reconnected will help. (Including a photo of your dual-filter setup because I only have one.)

Even if the extra pics don't help us solve your problem ... at least we get the enjoyment of seeing them . (Yep. I really am a selfish bastard he he.)


PS. You're sooo right that it pays to do just one job at a time because if you'd done that here you'd KNOW whether the fault was associated with your diaphragm change or your filter element change.

Perhaps the way the filters were changed led to some debris clogging the inlet strainer in your fuel pump?

Or perhaps you even left the clear plastic "shrink wrap" on the top of one of the new filter cartridges LOL! (After all, you do live the wrong side of the ditch.)

 

[Falco80]

I always shudder when I hear this quote Dan.

I'm not a believer in this attitude at all because to me it says "Don't bother with maintenance! Just wait for a breakdown!". (But I know you're joking.)

Maybe posting up some photos of your fuel supply/injection area with it all reassembled/reconnected will help. (Including a photo of your dual-filter setup because I only have one.)

Even if the extra pics don't help us solve your problem ... at least we get the enjoyment of seeing them . (Yep. I really am a selfish bastard he he.)


PS. You're sooo right that it pays to do just one job at a time because if you'd done that here you'd KNOW whether the fault was associated with your diaphragm change or your filter element change.

Perhaps the way the filters were changed led to some debris clogging the inlet strainer in your fuel pump?

Or perhaps you even left the clear plastic "shrink wrap" on the top of one of the new filter cartridges LOL! (After all, you do live the wrong side of the ditch.)

Hi Tom, i hope i have not left a small piece of plastic film on one of the filters.
When doing the filters i also took out the priming pump inlet strainer. I'm just thinking if that can be fitted with the ports not lining up properly. Might pull it out again to make sure. I've got one more day home now so i'm going to hit it hard today to try to sort it out.

Here are some pics ya selfish bastard!!

 

[lostmarbles]

Thanks for the pics Dan (Your engine looks great. It is so rare to look at old engines without seeing rounded hexes everywhere!)

I printed off the one showing your IP lever in the "stop" position and lifted my bonnet (hell ... it's even stopped raining today) and everything on mine looks identical.

I've not noticed anything of concern in the other pictures either.

So unless someone else spots something I've missed, we're no further ahead.

But how much work did you really do before finding the problem. (I see now that you removed the inlet strainer from your fuel pump too.)

Perhaps a piece of sh#t has gotten lodged under one on the check valves in your fuel pump? (That could explain the problem if it were to be limiting the fuel delivery to your IP.)



PS. How do you find that clear plastic fuel hose?

On petrol motors I find it hardens and discolours.

I've never used it with diesel but from the looks of things on your engine it may have the same problems. (I forego the benefit of being able to see my fuel and use "black rubber marine fuel hose".)

 

[Falco80]

Thanks for the pics Dan (Your engine looks great. It is so rare to look at old engines without seeing rounded hexes everywhere!)

I printed off the one showing your IP lever in the "stop" position and lifted my bonnet (hell ... it's even stopped raining today) and everything on mine looks identical.

I've not noticed anything of concern in the other pictures either.

So unless someone else spots something I've missed, we're no further ahead.

But how much work did you really do before finding the problem. (I see now that you removed the inlet strainer from your fuel pump too.)

Perhaps a piece of sh#t has gotten lodged under one on the check valves in your fuel pump? (That could explain the problem if it were to be limiting the fuel delivery to your IP.)



PS. How do you find that clear plastic fuel hose?

On petrol motors I find it hardens and discolours.

I've never used it with diesel but from the looks of things on your engine it may have the same problems. (I forego the benefit of being able to see my fuel and use "black rubber marine fuel hose".)

Hi Tom,
Replacing that plastic fuel hose is on my to-do list. It was already on there when i bought the BJ. I got new hose and clamps at home ready to go.

I'm at work now until the end of the week, but i've been thinking about the problem while i'm here. I think now it is definately a fuel supply issue. When taking it for a test drive last week i did notice some white smoke on occasions. Maybe it's sucking in air from around the inlet strainer (which i removed to have a look at ). I'm now 99% sure the EDIC arm is ok. It moves to all 3 positions when commanded and i can't really see what else it could be in that area.

So, when i get back home i'll rip off both filters, check them and check the priming pump housing where the inlet strainer is. I need to get it driving properly again as i'm getting new tyres next week.