POS Rotary Pump on 3B!!

[Ratpuke]

Awhile ago I posted up a thread about the coughing and surging in power that my BJ73's 3B exhibits, usually only when the engine is cold. The original thread can be found here: https://forum.ih8mud.com/diesel-tech-24-volts-systems/86336-surging-smoking.html

Up until recently these problems seemed to only occur in the late fall and early Spring - when temperatures are low enough not to be warm but not cold enough using the Webasto to pre-heat the coolant. In the winter I generally used the Webasto to heat up the engine so the problems weren't an issue in the winter.

To recap, the truck is a 1985 BJ73. It has a 3B with a rotory injection pump. When I got it, I could usually squeeze 800km out of a tank of fuel. Now it's empty at around 600km.

Over the past few months it has started to really run quite poorly. On a typical morning I start the engine up after glowing the plugs. The engine idles normally for a minute or so. I then back out the driveway and head off to work. I don't get very far - usually only a couple of doors down when the engine really starts to knock and lurch about (as though it was being driven by someone just learning how to drive a standard). The engine would normally stall out and then I have to restart it. It fires up again but this time I have to step on the throttle in order to keep it idling. It'll blow black smoke at this point. I keep the pedal down a bit longer and dial up the hand throttle - it keeps it running and idling ok until I make it to work. On the way home, after the truck has sat all day, it does it a bit, but not nearly as bad.

So, now that it's starting to become more of an issue, I decided to pop the hood and take a look to see if I could spot any air in the line (which was brought up in my past thread). Bruce and I had swapped out one of the fuel lines a year ago (ok, maybe 2 and I forgot to put the right hose back in so that's why it's still in there).

Upon inspecting the engine it was soon noticed (by RockDoc) that the rotary pump was covered in diesel. There wasn't a need to clean it up because it was apparent that diesel was coming out of the top part of the pump (as labeled in this picture

 

[Ratpuke]

So, in addition to the fuel leaking out of whatever that part of the pump is called, I noticed two holes that look like something should be in there. Any idea what, if anything is supposed to go in there?

I also took another picture showing the hose in which air bubbles accumulate:

 

[amaurer]

Bummer. I don't know anything about your problem, but could you post a pic of the whole pump? I've always wondered what the rotary jobs look like...

EDIT: Nevermind, you did while I was typing!

 

[Ratpuke]

Here is a very crude video sort of showing the air in the line. Unfortunately you cannot see the fuel coming out.

YouTube - Aug 05 2007 - VID00039

Ignore RockDoc's commentary in the background

 

[Ratpuke]

So, my question at this point in time is whether or not anyone has ever replaced/fixed a part on their rotary pump? Are they at all re-build-able?

If so, how involved of a job is it?

Do you have to pull the timing cover?


............

I'm crossing my fingers that someone can tell me that it's an "easy" fix that involves replacing a seal or something.

However, in a preemptive measure, I obtained a spare 3B with a rotary pump just in case this pump cratered. I have no idea what condition this spare pump is in. Perhaps I could get the spare rebuilt while the current one dies a (hopefully) slow death.



Thanks in advance for your insight and advice!

 

[roscoFJ73]

There could be air getting in through the leak on top. You could possibly fix that one but being an 85 model it could start leaking somewhere else.
My preference would be a complete new gasket and o ring kit right through the pump.

A rebuild is different to a gasket and o ring replacement ,although you would need the gaskets if it was rebuilt.
Rebuilds replace worn metal parts are usually around a $1000.

But if someone pulls it apart to do the gaskets and finds wear,then you got to do the whole lot.

 

[Radd Cruisers]

Two seals to replace, the one on the top of the pump a O-ring and the other is the one around the top of the pump.

Can been done in the truck carfully and cleanly.


Not sure why our fuel shrinks the orings but it does and then it leaks.


Edit, ps I do not ever remeber seeing thos cause poor starting issues?


Edit edit, if you do this job remember too mark the shaft position as on the pump in conjunction with the lever for proper postion.

Rob

 

[Ratpuke]

Oh - one more thing. There was a vac line off which looked to fit onto part of the rotary pump. I put it back on and I'll see if it makes any difference in how it runs.....

To be continued.

 

[Ratpuke]

Two seals to replace, the one on the top of the pump a O-ring and the other is the one around the top of the pump.

Can been done in the truck carfully and cleanly.


Not sure why our fuel shrinks the orings but it does and then it leaks.


Edit, ps I do not ever remeber seeing thos cause poor starting issues?


Edit edit, if you do this job remember too mark the shaft position as on the pump in conjunction with the lever for proper postion.

Rob

Sounds promising. Now, where can I source the proper seals?

 

[crushers]

i do beleive the part that is "missing" is the high altitude compensator... not suppied on all rotory pumps.
Dan has the seals.

 

[Radd Cruisers]

Sounds promising. Now, where can I source the proper seals?

Buy them closer to you for convience.

We do however carry a large amount of JDM parts and in house service all our vehicles.

Currently we are working on our dealers license and will be one of the only to sell and service in house.

If you need the seals please call us for a price.

Rob

 

[Eric Winkworth]

I always shop around for parts now, I've found good prices on certain things at 4 wheel, sometimes carquest or napa is cheaper for reman parts.... usually toyota is a rip but they have surprised me before...

cheers
Eric

 

[Ratpuke]

Anyway..........


I'm going to try to track down a manual.
Then I'll track down some seals.
Then I'll see if I can figure out what to do with the seals.

Then I'm going to try to find out where the air is coming from (in hose upstream of the pump).
Also have air in my rad... need to get rid of that.

It may take some time but I'll post up when I finally make some progress.

In the mean time, thanks for the help thus far.

 

[canucksafari]

Not sure why our fuel shrinks the orings but it does and then it leaks.


Edit, ps I do not ever remeber seeing thos cause poor starting issues?

Rob

The Hydrogen process used to remove the sulphur to make ULSD also removes the aromatics from the diesel. The aromatics are which keep the rubber rings, seals and hoses soft and pliable. While they add lubricant (many times just veggie oil) to make up for the lubricant which was provided from the sulphur, there is nothing available to make up for the lost aromatics. 1994 is the year most diesel FI systems went from rubber to Viton type seals, gaskets and hoses.

When my rotary pump started leaking, at first it was just dripping, but when it got worse, it allowed air to get in the IP which made starting rough until the air was cleared out.

Ratpuke, I recommend you do all the seals. I know of others who have just done the seals which are leaking only to have another like the shaft seal go a month or so later. It is a pretty sure bet that if a diesel fuel injection shop pulls it apart they will find some wear to justify a full rebuild. If it is a 20 year or more old pump, than a rebuild is probably a good idea. Also allows you to maybe put in a bigger plunger if you are planning on running a turbo with more boost.

 

[Ratpuke]

Question of the day: How do you time a rotary pump? Lowenbrau says there is a thing that you screw in and out and he thinks it similar to timing the 1HZ or 1HDT. Anyone have experience doing this?

 

[cruiser_guy]

How do you time a rotary pump?

Unless you have access to the equipment in a diesel injection shop I wouldn't bother trying to time the pump. I tried doing the 3B when I rebuilt it with the inline pump and the best I got, according to the injection shop, was 7 degrees out and that was following the OEM manual.

 

[canucksafari]

Question of the day: How do you time a rotary pump? Lowenbrau says there is a thing that you screw in and out and he thinks it similar to timing the 1HZ or 1HDT. Anyone have experience doing this?

There is a plate on the side of the IP (timing cover plate). On mine you line up the timing marks on the pump to the mark on the timing gear case (which should give you 6 degrees BTDC). Then you remove the plate and attach the timing tool http://cgi.ebay.com.au/Tool-for-tim...ryZ35625QQssPageNameZWDVWQQrdZ1QQcmdZViewItem You adjust the timing nut until it is set according to your manual specs for your engine. In my case that is 0.75 mm. If you are turboed, it is best to have a fuel injection shop with a dyno set it for you. Even if you are not turboed, it may be cheaper to have a fuel injection shop do it rather than buy the tool. In the end, that's what I did. But, its a good tool for a club to have on hand, if you have a few rigs with a rotary pump.

 

[Ratpuke]

Update

Just a little update on this pump...

Upon the recommendation of several Cruiserheads I sent my spare 3B pump down to Jim's Fuel Injection shop in the lower mainland to have it rebuilt. Figured that'd be the best as the truck started to really run rough and it was getting to be quite cold out. Turns out, the colder the weather, the better the truck ran (thickening of the fuel?) so this bought me a bit of time. Anyway, sent the pump down late Oct. and got it back a couple weeks later. It came back looking fantastic.

Was finally able to get it into the truck a couple weeks ago, thanks to the assistance of Deny. It was a tight fit, but it went in and as it turned out, could only go in one way so timing wasn't an issue.

The pump must've been slowly dying over the past couple of years. I've mentioned that the truck has been surging and smoking in another thread. I'll have to wait until warmer weather to confirm it, but I suspect these issues are a thing of the past. Incidentally, the clear fuel line has been taken out and the original hose has been put back in. Everything has been tightened up, and now the Webasto is working better than ever. My fuel mileage has increased substantially and the truck has a lot more power.

So, thanks again Deny for the help with the install and for Bruce and Rob for suggesting/shipping the pump to and from the shop.

 

[lostmarbles]

Cool.

Always nice to hear a happy ending.

 

[Ratpuke]

Thanks. When I get a chance, I'll take another look at the pump that came out of the truck and see if replacing the seals is all it needs.