3B diaphragm replacement (1 Viewer)

[Paul Rowand]

my 81 seems to be doing this.....
when I step on the fuel it hits what seems to be a hard spot and does not push to the floor easily. when I back off the rpm stays high, until i hit it a couple of times and it comes back down.... My acceleration is slow, not getting the diesel. What needs to be changed?
the venturi......?

 

[duncanrm]

my 81 seems to be doing this.....
when I step on the fuel it hits what seems to be a hard spot and does not push to the floor easily. when I back off the rpm stays high, until i hit it a couple of times and it comes back down.... My acceleration is slow, not getting the diesel. What needs to be changed?
the venturi......?

This sounds more like a throttle cable sticking/binding issue or an issue with the butterfly mechanism in the throttle body. A diaphragm problem cannot be felt through the pedal.

 

[Paul Rowand]

This sounds more like a throttle cable sticking/binding issue or an issue with the butterfly mechanism in the throttle body. A diaphragm problem cannot be felt through the pedal.

I cleaned the cable and put WD40 down the cable line......could anything else, you can think of, cause this....
it does not happen all the time....very frustrating

 

[duncanrm]

I cleaned the cable and put WD40 down the cable line......could anything else, you can think of, cause this....
it does not happen all the time....very frustrating

I would do a full inspection of the cable, accelerator pedal mechanism (including hand throttle linkage), butterfly mechanism and return spring on the butterfly, a check that your floor carpets (if any) arent intefering with your pedal as well.

Also finally.. can you confirm your 3B has an inline injection pump? Some do have the radial injection pumps.

 

[Paul Rowand]

I would do a full inspection of the cable, accelerator pedal mechanism (including hand throttle linkage), butterfly mechanism and return spring on the butterfly, a check that your floor carpets (if any) arent intefering with your pedal as well.

Also finally.. can you confirm your 3B has an inline injection pump? Some do have the radial injection pumps.

Yes inline injection pump with the HAC unit......I will go over it all and see where the issue is....
Maybe WD40 the hell out of everything that moves.... Thank you for the advice. You guys DU sure have some great 4x4ing roads. I have been following some of the adventures on Youtube......crazy.!!

 

[gerg]

As duncanrm said that sticking sounds like linkage or something of that nature. The slow engine/lack of fuel is probably a separate issue but could very well be how it was tuned. People play with these engines with very little knowledge of them. Bad combo. I'm in Aldergrove. Your welcome to drop by Saturday. I'll be in the garage. Message me.

 

[gerg]

Ohh and I forgot to mention my wife and children will be there too. Just in case your wondering.

 

[Paul Rowand]

As duncanrm said that sticking sounds like linkage or something of that nature. The slow engine/lack of fuel is probably a separate issue but could very well be how it was tuned. People play with these engines with very little knowledge of them. Bad combo. I'm in Aldergrove. Your welcome to drop by Saturday. I'll be in the garage. Message me.

 

[Paul Rowand]

Hey Greg, thank you for your reply....
I have been trying to find someone who knows how to tune the 3B......I have been reading lots but still do not know what to do.

 

[Paul Rowand]

Ohh and I forgot to mention my wife and children will be there too. Just in case your wondering.

No Problem, with that...I will confirm with you by the end of the day....
I have other stuff for Saturday, my wife always has a "too do file " for me, out side of my own schedule.
Are you an expert on these engines? Mine runs well when this problem did not just appear, and it could use the valves adjusted
I was going to try that myself but thought better.......toyota wanted 600 to adjust the valves...???, $%&#...them

 

[gerg]

Sure we can adjust your valves. I'm no expert but I can fill you in on the common issues and regular maintenance

 

[Squash]

Well folks my hats off to anyone replacing a LHD BJ70 in under 2hours.
Did remove the EDIC as mine also has an ARB compressor/pump eating up real estate. Luckily my diesel shop called and for $30.00 my part was in...sensing my growing frustration I decided to pick up the part, grab a black coffee and a chicken soup for my soul.
Decided a haircut and beard trim were in order because pretty women always calm my nerves.
The above accomplished and using my handy tool the two bottom screws came out in under 5 minutes!
Did make a handy tool for those impossible to see screws, basically a large electrical shrink tube able to find the screw and stay on said screw....
Thanks to those of you who contributed to this thread and forum.

 

[Rustypuss1]

I agree that the symptom of a damaged diaphragm is slightly higher idle. If you do not deal with it it will just get worse until teone day your 3b will just rev till its screaming .... I've heard one do it.

Mine doin that now-slowly got worse till reving high rpm on idle now-about to change-in 86 coaster

 

[Rustypuss1]

I agree that the symptom of a damaged diaphragm is slightly higher idle. If you do not deal with it it will just get worse until teone day your 3b just rev till its screaming .... I've heard one do it.
[/QUOTE

 

[Macktastic]

Chiming in to add, holy moly what a difference this one part makes on the engine behavior. Cut idle from 1100 to 600, no more excessive smoke (white on startup, blue running), and much more in control of the revs with the pedal. Attached is what my old one looked like coming out.

I'm a novice mechanic and was able to do it in about 3.5 hours without taking the fuel system or the EDIC out (just removed the arm). I have some videos or the process if anyone wants/needs them at any point, using the phone camera and flashlight actually made it a lot easier to see around the corners.

 

[Jollopy41]

Chiming in to add, holy moly what a difference this one part makes on the engine behavior. Cut idle from 1100 to 600, no more excessive smoke (white on startup, blue running), and much more in control of the revs with the pedal. Attached is what my old one looked like coming out.

I'm a novice mechanic and was able to do it in about 3.5 hours without taking the fuel system or the EDIC out (just removed the arm). I have some videos or the process if anyone wants/needs them at any point, using the phone camera and flashlight actually made it a lot easier to see around the corners.
View attachment 3106146

experiencing something like this now, white smoke during startup and a little blue smoke once in a while. Also recently replaced my diaphragm because RPM suddenly went up really fast.

 

[KIWIALEX]

Thought I would post some pics of this. I did one earlier this summer and had some issues finding info on removal. Specifically, the nut that holds it to the shaft is an 8mm.

Pics might be useful to someone.

This engine is hanging on a hoist and the edic motor and mount is removed for better access.

1. Where to find the diaphragm
2. With the cover removed
3. Close up so you can see where the nut goes - you can see the threads on the right side of the shaft inside the housing.
View attachment 180854View attachment 180855View attachment 180856

Hey mate hopefully you get this. What are the symptoms if a faulty diaphragm? Or at least your reasons for changing it