4JB1T cranks but won't start

[Roderunner]

I would also consider checking the voltage at the cut off switch while cranking the engine, there may not be enough juice left to keep the switch open if the starter is stealing most of it, hence my previous suggestion to try tow starting it.

[manders]

Roderunner wrote:I would also consider checking the voltage at the cut off switch while cranking the engine, there may not be enough juice left to keep the switch open if the starter is stealing most of it ...

For more than a handful of my troubleshooting attempts, I had a second "jump-starter" battery hooked up to ensure that I had sufficient CCA.

But I'll also admit to skipping past the potential of insufficient juice once we were able to verify fuel spattering from the individual injectors when we bled them; I am assuming that the solenoid is truly on/off rather than partial-but-still-insufficient-to-start fuel flow.

[geeves]

if they were spattering under cranking the solenoid is ok. Its sounding like timing. An easy mistake is to set the cam or pump 180 degrees out.Then everything happens on the wrong up stroke

[manders]

Sorry for the delayed follow-up ... I've been traveling.

As y'all rightly suspected, the local mechanic also diagnosed the issue as incorrect timing, likely because of "... several white paint marks on the vibration damper that someone must have thought was TDC because it looks like the gears marks (sic) line up with those marks".

He tinkered a bit more and got it to work. Here's the comments he left on the final invoice:
I removed the front cover and idler gears again then lined up cam, crank and fuel pump gears so all alignment marks on the gear teeth meshed. I tightened
both idler gears down then re-installed front cover and vibration damper tight. I cranked engine and it started right up, sounds good and there is good throttle response.


I've been baby'ing it for the 25+ miles since picking it up and everything seems to be running just fine!

Thanks for the assistance, advice, and good cheer!

MAnders.

[geeves]

Good result. Now remember the 4jb1 likes to rev. (by diesel standards at least) Peak power is between 2500 and 3500 and its not going to complain if it hits 4000 from time to time. Dont baby it like a big American diesel.

[manders]

geeves wrote:Good result. Now remember the 4jb1 likes to rev. (by diesel standards at least) Peak power is between 2500 and 3500 and its not going to complain if it hits 4000 from time to time. Dont baby it like a big American diesel.

Thank you VERY MUCH for that insight. The only other diesel I've ever had is a 6-cyl Cummins, which is just about the size of the Trooper ... not the engine ... the whole vehicle!!!

[geeves]

Cummins are very good engines but they are designed like truck engines and will pull from idle but never rev. Small Jap diesels are not like that. The old cummins would run out of revs about the same place as the 4jb1 wakes up yawns and starts working. I think Cummins are making a few small high speed diesels now