BJ74 13BT starting and power conundrum (1 Viewer)

[gifu]

1986 BJ74
180k miles
IP freshly rebuilt.
Injectors checked.
new fuel filter
Pump timed via hash marks on gears and such; slight bit of advance.

starting is terrible. I am at 6200’
Need to super glow it below 60f
Need to double super glow if it’s really cold.

Throttle response and smoke are terrible. Normally 13bt are so responsive off idle that BJ74 owners add a second spring to the throttle linkage. This thing revs like it’s waking up from a nap. And it’s smokey; fuel. Black.

Compression is not great but within spec.
300, 320, 340, 290
BUT, at 6000’ I can correct compression numbers by .84 so really…
350, 380, 400, 340
which… is acceptable.

so… question is… what are next steps?
pull timing case for third time to recheck timing for third time?
Pull pump and injectors and assume shop screwed something up?
that’s all I got. ideas? Thoughts? Anecdotes?

 

[Nz Nath]

The timing should be set by spill timing against the timing mark on the crank pulley (11deg btdc). You adjust it by loosening the bolts that hold the pump to the timing case, znd rotating it on the slotted holes.

Do you use the throttle pedal when starting? Someone posted the owners manual somewhere on the forum, you're meant to partially depress the throttle for warm starts, and full throttle for cold starts.

 

[gifu]

yes I use throttle when starting.
This isn’t a case of… I wish it started a little better. It’s more like… wow this is not going to start… crank for 15-20 seconds sometimes 30-40 seconds … then barely starts and billows black smoke.
just took timing gears apart for third time to triple check I’m not a tooth off.
There’s no way to tell where they were before because the IP drive gear comes off with timing case cover. But here’s photographic proof that timing gears are where they should be.

 

[Nz Nath]

You still need to spill time it bro, there’s probably 8deg of adjustment either side of the ideal.

 

[gifu]

I need a piece of old fuel pipe to cut up.
On all my old diesels I’ve been able to just advance the timing and call it good.
You can hear it if its advanced too far… starts to rattle more. this thing always acts like its retarded a bunch of degrees…

 

[FJBen]

If your timing gears were correct, then no point in pulling to confirm they are right. Something very bad would have to happen for them to be off.

You can spill time it to get back to factory then advance from there.

So tons of black smoke is too much fuel/not enough air.
These are really simple questions so sorry, but no plugging in the intake/ air filter? For a test you could disconnect the intake to the turbo to see how it breathes/starts without that.

You are within spec, albeit in the lower end, and you have 17% difference in compression which is still under the spec of 28PSI.

Did this all start after the IP rebuilt and injectors or just slowly happening? IF right after the IP rebuilt, I would be checking that with the company that did it again.


I'm wondering with the lower compression and lack of air or too much fuel if it's just a bad combo?


Do you have a wilson switch or how are you super glowing at 60F? My glow screen light won't come on until like 20 degrees or colder. The 13BT usually starts really easy. I've started in below zero several times pretty quickly without any other block heater or the like.

 

[gifu]

When I bought this rig (two years ago) it had terrible exhaust leaks at the manifold. I decided to pull the pump, injectors, and turbo. Had pump rebuilt ($2200!), injectors tested fine. Resealed turbo manifold and put it all back together.
Because I mostly work on 1HZ/DT motors, I didn’t know the IP could be removed without opening the timing case. When you open the timing case the IP drive gear comes out with the cover (bearing is a press fit that requires heat to remove).
Since it immediately ran terrible I feared I had misaligned the timing gears so I opened it back up to double check.
Now that I’ve check the timing gears and checked compression… my last thought is to pull pump and send it back. which I’m hesitant to do because they charge $400 just to test the pump. So if it’s not the pump… then $400 blown.
Super glow… the coolant temp sensor at the thermostat housing is unplugged which makes the glow computer stay on for max glow.