SD23 fuel injector 'pump' head scratch.

[rlaggren]

In cases where there is a weak starter or battery it sometimes helps to unload the engine by sealing off the intake (put you hand tight over it - it should grab you good) and let the starter spin up to speed, then remove your hand. The starter has a much easier job of it w/no air in the cylinders and it gets some speed into the flywheel; when you "open" the intake it's like popping the clutch. I have done this a couple times w/big 6-cyl marine engines that didn't have enough battery left - it does work. But you need a remote start button or a 2nd person.

But listen to Al and do the nitty gritty stuff before throwing money at the engine. Without all the details in order no amount of the green stuff will get it going anyway.

Rufus

[igaroot]

New battery at 760cca cranks good. Would slowish cranking be the whole problem?

Absolutely! Yes! It must crank fast, or game over.

Two batteries? More CCA? Better Starter? I hear denso's kick arse!

Did you address Philip's suggestion that perhaps this CAV IP needs an external fuel pump?

Yes, there is an electric fuel pump in the tank that pumps in the on position. Works good.

Reading up on the CAV system (in the generic Nissan SD22/23/25/33 Service Manual: non-vehicle specific, it covers agricultural/industrial setups), they show testing a mechanical lift pump, specs are 5.7-8.0 PSI feed pressure to the IP.

Good to know. I might put a gauge on the fuel delivery.

Yesterday, when I had the injector lines disconnected I put paper towels under them. There was a 4" circle of fuel under each line after cranking for ~30sec.

This generic manual is not very in-depth, I'm afraid. It looks like the CAV was shipped in two different shutoff configs, perhaps more. It looks as if there might be TWO shutoffs on this IP, the stop lever at the front top (spring-loaded to RUN, I think) . . .

I'll try with the spring loaded. Wasn't loaded when it started last time. Worth a try though.

. . . plus what the manual is calling an "autostop solenoid", located perhaps at the bottom rear of the IP. Looking at your single IP pic, where does that orange wire go?

Does not appear to be the oil pressure switch. If it connects to a solenoid on the IP, perhaps you do not have 12v to it while cranking?

Wow you have eyes like a hawk(lit and fig)! I noticed this yesterday. I did not confirm voltage, at that time. Definitely worth checking out.

If me glow plug circuit is working properly (I know, I need to get the multimeter from work), I think my main focus should be on cranking the engine faster (jump). Shut offs at the IP will be investigated, and perhaps the pressure from the lift pump in the tank.

Good stuff Al. Thank you. Still want to buy it?

[igaroot]

In cases where there is a weak starter or battery it sometimes helps to unload the engine by sealing off the intake...

Rufus, "unloading" the engine may be just the thing for this little boat pusher.

[asavage]

Two batteries? More CCA? Better Starter? I hear denso's kick arse!

It's hard to advise without hearing it, but generically you want a cranking RPM above 200 RPM on a small diesel to reliably light it off. That's 3+ revs per second.

Is the battery a "good" one? I like Interstate and detest Exide. The condition of the terminals can make a big difference too, with the bolt-on temporary terminals often having a fairly high resistance at the amperage a diesel draws to crank.



These are designed for temporary use only, until a real terminal can be swedged on to your cable. The SD OEM cables as installed in the 720 PUs are especially heavy (0 gauge or better).

Yesterday, when I had the injector lines disconnected I put paper towels under them. There was a 4" circle of fuel under each line after cranking for ~30sec.

That may not be enough -- I would think that a bit more fuel than that after 30 seconds, would stain your paper towel.

I'll try with the spring loaded. Wasn't loaded when it started last time.

The manual I have is not clear on which direction is "RUN" and which is "STOP". Of course, almost none of us know anything about the CAV IP.

If me glow plug circuit is working properly (I know, I need to get the multimeter from work) . . .

If the GPs are the "slow" GPs, they are very tolerant of leaving them on too long. But if they are the alter "fast" GPs, they can be burned out fairly easily. If you have one out again, buff off the side and write down the number and post it, we can tell you which control system is needed for them.

. . . I think my main focus should be on cranking the engine faster (jump).

Jump cables often can't carry enough current to help start a diesel that isn't in perfect tune. Better to sort out your cable issue (if you have one) and borrow a good battery, etc.

Good stuff Al. Thank you. Still want to buy it?

Yes. Maybe. It's not at the top of my list, but it's the right color

[igaroot]

Is the battery a "good" one? I like Interstate and detest Exide. The condition of the terminals can make a big difference too, with the bolt-on temporary terminals often having a fairly high resistance at the amperage a diesel draws to crank.

These are designed for temporary use only, until a real terminal can be swedged on to your cable. The SD OEM cables as installed in the 720 PUs are especially heavy (0 gauge or better).

The battery is a Platinum Kragen genericish model 96. Where would one find a good swedger? Can I do it myself? Does it involve melting lead?

If the GPs are the "slow" GPs, they are very tolerant of leaving them on too long. But if they are the alter "fast" GPs, they can be burned out fairly easily. If you have one out again, buff off the side and write down the number and post it, we can tell you which control system is needed for them.

They are NGKs and appear original. I'll post when I check um' out again.

[asavage]

Where would one find a good swedger? Can I do it myself? Does it involve melting lead?

While you can buy the swedging tool, it isn't practical to buy unless you do a lot of it. I don't own one, for example. I have a local auto electric place do my cable work.

Member dieseldorf mentioned solder-in-place terminals in this post.

[igaroot]

Checked the GPs today, or at least the one in front. All four appear to be the same vintage.

NGK model #8453 no match in the following thread.

SD2X Glowplug information thread

Would be nice to know if I can keep em' on for 20sec+ ie. non quick start.

I really need to get the multimeter. I have no way of knowing if my direct GP circuit is working. Cold combustion chambers I fear.

The shut off solenoid at the IP is connected to the ignition at the acc. position. The same as the lift pump in the fuel tank. Multimeter would confirm voltage.

My battery's sticker indicates 770cca. Cable swedging is in my future.[/u]