My first 13B-T compression test (1 Viewer)

[Allen Stanion]

I'm going to be doing my first compression test of my 13B-T Diesel in my 86 BJ74. I have a few stupid questions that can be easily answered by experienced diesel cruiser owners.

1. The manual says "Remove nozzle, ring packing and nozzle seat".
- Are the "ring packing and nozzle seat items which become compressed by the injector body when bolted down tight? Are they reusable, or would I need to buy new to do a compression test?

2. 13B-T Manual says: "Warm up and stop engine, Remove injection nozzles, Fully open the throttle valve"
- Is the translation of "Fully open throttle valve" = "have someone put the fuel pedal to the floor while turning the key to crank the engine"?

3. After the test is completed the manual says "Install injection nozzles, leakage pipe, injection pipes, then start engine and check for leaks".
- Do the injection pipes need to be filled/purged at all before starting?

Are there any other tricks, suggestions or recommendations anyone can make to help me do this test more smoothly? Again, first timer concerned about doing something incorrectly.

Thanks in advance

 

[dabasscow]

Not sure which manual you have, the one I have doesn't mention full throttle to start in the injector section. In the manual download listed on this forum, make sure you are reading the 13bt notes not the 3b. Usually recommended to replace the small copper washers and rubber seats when installing the injectors, they were fairly cheap here in Oz.

There is a pump for bleeding the fuel system, has a bleeder nipple on the fuel filter mount, using a tube and bottle, pump until no air comes out and close off the nipple. Start normally, mine started with a few seconds more then normal no issues.

 

[Allen Stanion]

Not sure which manual you have, the one I have doesn't mention full throttle to start in the injector section. In the manual download listed on this forum, make sure you are reading the 13bt notes not the 3b. Usually recommended to replace the small copper washers and rubber seats when installing the injectors, they were fairly cheap here in Oz.

There is a pump for bleeding the fuel system, has a bleeder nippleon the fuel filter mount, using a tube and bottle, pump until no air comes out and close off the nipple. Start normally, mine started with a few seconds more then normal no issues.

These are the 13B-T Engine Manual cutsheets for compression testing. You can see where it says "Fully open the throttle valve" in section 3. C. About half way down the page. On the page where it instructs how to reinstall the injectors, it doesn't mention purge of the injector tubing...

 

[dabasscow]

Thats page is for the B and 3B not 13bt, you want the next page em33 says similar. The full throttle reference is for the compression test it self (though it was in reference to starting after reinstallation of injectors), yep need to have the pedal to the floor is the way I read it. I replaced the fuel filter when I did mine, well the pump and bleed I Mentioned is for that, sorry to cause confusion.

 

[Allen Stanion]

Thats page is for the B and 3B not 13bt, you want the next page em33 says similar. The full throttle reference is for the compression test it self (though it was in reference to starting after reinstallation of injectors), yep need to have the pedal to the floor is the way I read it. I replaced the fuel filter when I did mine, well the pump and bleed I Mentioned is for that, sorry to cause confusion.

Agreed. Here's the 13B-T EM-33 Sheet. Still says to "fully open the throttle valve" while doing the compression test. <shrugging shoulders> Not sure why really, doesn't make any sense (to me).

I appreciate the feedback. Even if it's a learning curve, one feels less alone when other folks chime in!

 

[dabasscow]

at a guess I would say to avoid any air restrictions while doing the compression test.