1HD-T over reving on start up

[chrisspaulding]

Thanks for the feedback, direction and advice. I think Dave is right about the full cold start setting on the ACSD. I messed with that thing SEVERAL months ago. I needed a TPS for the transmission computer and did not realize that there was one already on the pump. I was trying to connect an aftermarket TPS throttle to the linkages and had loosened/removed some of the mounting screws related to the ACSD. I could have messed up the base setting, or it could have gotten messed up during shipping. Either way, I'll find the blanking plate and Oring so I can remove the device. We do not get that cold here in NC. I'll update once I get it sorted. Thanks again for all the support and assistance!

 

[chrisspaulding]

Yeah... I think I'm wrong about the ACSD...

 

[Delancy]

Chris,

Picked up a 1HZ for a project that had been pulled and palletized an unknown period back, then shipped and further stored. It exhibited similar symptoms, being a very high idle on startup that was unaffected by throttle linkage movement.

Popped the cap on the IP and there was just enough surface rust for the governor to have stuck in whatever position it'd been in during the duration it storage/transit.

Pulled IP and currently sitting on bench at local rebuilder that, surprisingly has all kinds of experience with Denso pumps, parts/seals on hand (12V Denso fuel cut $45.00) that quoted $400 to tear down, blast, re-seal, if nothing internal needed replaced.

Diesel tech that HZ is sitting in said it's not that uncommon an occurrence on loose engines that have been stored, shipped, and/or laid over a some point in between, saying there's enough moisture in the air to facilitate corrosion, if there's no fuel present in the pump to prevent.

Don't know that it's your issue or not, but something to consider if all else fails.

Chris

 

[chrisspaulding]

Chris,

Picked up a 1HZ for a project that had been pulled and palletized an unknown period back, then shipped and further stored. It exhibited similar symptoms, being a very high idle on startup that was unaffected by throttle linkage movement.

Popped the cap on the IP and there was just enough surface rust for the governor to have stuck in whatever position it'd been in during the duration it storage/transit.

Pulled IP and currently sitting on bench at local rebuilder that, surprisingly has all kinds of experience with Denso pumps, parts/seals on hand (12V Denso fuel cut $45.00) that quoted $400 to tear down, blast, re-seal, if nothing internal needed replaced.

Diesel tech that HZ is sitting in said it's not that uncommon an occurrence on loose engines that have been stored, shipped, and/or laid over a some point in between, saying there's enough moisture in the air to facilitate corrosion, if there's no fuel present in the pump to prevent.

Don't know that it's your issue or not, but something to consider if all else fails.

Chris

Hello Chris!
Thank you! Very very helpful. Gonna mess with it more today and see what I can do.
Thanks
Chris

 

[chrisspaulding]

Removed the cold start valve. Was able to get the blanking plate and Oring from a local diesel shop.
Started it up, revved out of control, did not shut off with key. Kept running and revving extremely high. I hopped out of truck to disconnect battery. Engine died before I could disconnect battery... Didn't hear a bang, no rods through the side of the block. Hope it just shut down and did not do any damage.
I'm pulling the injector pump and sending it to Delancy's shop.

Can someone please tell me there's a high rev cut off on the IP that cut off the fuel or something to that effect...

 

[Dave 2000]

The ONLY thing you can do when experimenting with diesels is to have a large wad of cloth ready, make sure you have clear access to the air intake, if it runs away then you can lob the wad into the intake. It will stop the runaway, I am now wondering if there was oil in the air intake, if it stopped awhile AFTER the key was shut off? Now may be safe to try again...........with the cloth ready!

The throttle stop at the end of the travel is set at the shop for maximum revs, about 4,400 is the max?

regards

Dave

 

[mudgudgeon]

The governor in the IP controls maximum revs. Should be 4500rpm max.

If there is a problem with the governor, it may fail to limit rpm.

If it's revving out of control and failed to shut off with the key, I'd be inclined to get the pump checked by a diesel shop.

IP rebuild vs engine rebuild? Been there done that, I know what I would choose

 

[IanB]

The ONLY thing you can do when experimenting with diesels is to have a large wad of cloth ready, make sure you have clear access to the air intake, if it runs away then you can lob the wad into the intake. It will stop the runaway, I am now wondering if there was oil in the air intake, if it stopped awhile AFTER the key was shut off? Now may be safe to try again...........with the cloth ready!

The throttle stop at the end of the travel is set at the shop for maximum revs, about 4,400 is the max?

regards

Dave

My buddy is a Cummins guy, and says they use a piece of 2x6 to cover the turbo inlet to stop a runaway if required, but the turbo is up higher and more accessible in that engine bay (1st gen Ram).

Would the wad of cloth jam in the turbo inlet and choke it I guess? Would that not damage the blades, or is that considered an acceptable risk to prevent engine damage?

 

[Delancy]

Chris,

Had you verified the fuel cut solenoid to function before this attempt to start?

They're non-op with no power, closed until power opens, so ignition off with a runaway won't stop.

If you're not getting enough juice (10.7 for 24V cut. Like 7 for the 12V) it won't open, so my uneducated opinion is its gummed up, rusted, or other debris is preventing plunger from closing.

Have been thinking about how to get this functioning for a test run at comfortable RPMs, since it'd be a much better feeling rebuilding a known problem IP on a good running engine, versus rebuilding on an unknown.

Have a means to smother intake, or stem the fuel flow, ready!! Could probably pinch the hose with hemostats, but a planned intake blockage would be prudent.

I don't know all that the HD requires that the HZ doesn't, and experience is limited to VM and HZ, but I'd disconnect the fuel cut, disconnect everything unecessary to fire it up......which on the HZ is no more than the starter, with alligator clipped jumper from battery to fuel cut.

When the VMJ73 arrived several years ago, I was bound and determined to get it running......mostly because I didn't care if I screwed it up, but still went through normal process before starting unknown. Drained tank, bleed fuel at fuel filter, replaced fuel filter, then primed with good fuel.

After many attempts, it wasn't getting fuel to the fuel rail, so loosened the fuel return line and pumped diesel through the fuel system, noticing build up in the discharge from the return line.

I didn't bother with anything past IP, which might've been beneficial, too (if the JB welded heads had held) but I think (operative) IPs free flow fuel, (edited: free flow through the body, inhibited from flowing beyond) so it's possible to semi-flush with fresh diesel.

I'm from the old school, firmly believing that a BFH is the best tool in the arsenal. In this case, may try tapping the side of the IP with a heavy screwdriver, to see if that helps unstick it.

I know you're patient and deliberate.

Based on, it's my uneducated opinion to try all possible to, at the very least, get it running and idling at a manageable RPM, just to make sure an IP rebuild isn't solution for a much larger problem.

 

[mudgudgeon]

My buddy is a Cummins guy, and says they use a piece of 2x6 to cover the turbo inlet to stop a runaway if required, but the turbo is up higher and more accessible in that engine bay (1st gen Ram).

Would the wad of cloth jam in the turbo inlet and choke it I guess? Would that not damage the blades, or is that considered an acceptable risk to prevent engine damage?

I don't think the suggestion is to put a wad in the turbo inlet, more so in the air box inlet. And use a large enough bundle that it's not going to enter the intake, a towel etc

 

[mudgudgeon]

Chris,

Had you verified the fuel cut solenoid to function before this attempt to start?

They're non-op with no power, closed until power opens, so ignition off with a runaway won't stop.

snip


Based on, it's my uneducated opinion to try all possible to, at the very least, get it running and idling at a manageable RPM, just to make sure an IP rebuild isn't solution for a much larger problem.

I don't think that's correct. Ignition off should close the fuel stop solenoid.
You may be correct that the solenoid is not operating correctly and sticking open, but that doesn't explain the runaway engine.
If solenoid is stuck open, the engine should still only run at idle.

As for the last paragraph, having had an engine runaway due to an IP failure, I'd suggest caution is possibly a less costly option than persisting with restarting an engine that may runaway again.

Check as many basics as possible. Solenoid function? oil in intake? or oil in cylinders
(was oil squirted into cylinder before storing to prevent rust, could take a while to burn off)? Throttle in idle position, pump timing correct?

Also get the tacho working so you can see if rpm is actually high enough to warrant panic. You should be able to let the engine rev to 4500rpm with no danger.

 

[Dave 2000]

Would the wad of cloth jam in the turbo inlet and choke it I guess? Would that not damage the blades, or is that considered an acceptable risk to prevent engine damage?

You have to get your plan together before starting. If the tube leaving the air filter is larger than the entrance to the turbo then as the wad of cloth gets drawn into the pipe it gets wedged as the pipe narrows, in effect making the possibility of air getting through even more unlikely and the wad unable to travel down and reach the turbo vanes. If the tube is the same diameter then a piece of flat plate, something that is larger than the turbo intake, and cannot collapse under the vacuum and yet small enough to be able to drop over the inlet with ease. The normal method is to release the intake pipe from the air filter making access easier to block.

The OP stated the engine was running fine, and was then simply fitted, so corrosion is unlikely,but is it possible the original vehicle was gasoline? It does not take a lot of gasoline to cause a diesel engine to runaway, seen that before.


regards

Dave

 

[Delancy]

Ignition off should close the fuel stop solenoid.

Right.

My statement was, if solenoig previously worked correctly, now doesn't, it may be indicative build-up in the IP, because it's sticking open, and a non-op solenoid will remain closed.

The only way the plunger could remain open is if something is preventing it from closing. Even if the spring is missing, it will settle to the bottom of the filter.

The filter is probably gummed up with storage sludge, the kind that occurs when diesel is left to evaporate, or worse yet, rust.

Chris,

You can pull the solenoid (on HZ at least) to inspect, without taking off the cap, if you've an open end wrench to sacrifice, but be careful to not round the top.

I figured this out the hard way (didn't think it'd require FSM, which I didn't have handy at the time) but it's easier to keep track of the spring during removal and installation, with power to solenoid (alligator clips) since it'll suck the plunger into the body, holding spring captive. Have to be careful with it being hot, obviously.

restarting an engine that may runaway again.

Only a runaway if you can't stop it and no harm in starting, IF it can be stopped. (**Disclaimer: no harm in starting if it is in a condition to start, i.e. lubed, fueled, and without internal damage that will otherwise be unknown, until it's running or torn down.)

Also get the tacho working so you can see if rpm is actually high enough to warrant

Not an easy proposition. The tach is an 12V F/H variant and sensor accepts BH pick up.

The HZ/HD IPs use a different signal (voltage, amperage, whatever it is. I won't pretend to know) that pegs the tach, with ignition switch on, engine off.

This is a self serving challenge, since I want to be proven wrong:

There's no conventional means to adapt the IP pick up to the VM tach.

 

[mudgudgeon]

Only a runaway if you can't stop it and no harm in starting, IF it can be stopped. (**Disclaimer: no harm in starting if it is in a condition to start, i.e. lubed, fueled, and without internal damage that will otherwise be unknown, until it's running or torn down.)

Yes, agreed. You capitalised the key word there.
On last start, the engine did not stop with ignition off, revs at an unknown high rpm.

No internal damage? Hopefully not yet.
That's my point. Having had my 1hd-t runaway, it left a permanent question mark on state of the engine.
Mine revved beyond red line, the tacho needle went off the clock, a 1hd-t at 6500rpm plus is a fearsome beast!
In 5th gear, mine accelerated along the highway like it had been stung on the ass .
It took all my effort with both my feet on the brake, pulling against the steering wheel to stall it in 5th gear.

For the OP, how many times are you willing to roll the dice on an expensive to buy, expensive to rebuild engine?

 

[bumpstopbrawler26]

When it revs up, how clean is the exhaust smoke? Have you had any of the throttle linkage off the top of the pump? The throttle shaft that goes through the top pump cover is splined, and if that's been installed a spline out it will rev on its own as soon as the pump starts spinning. It's a really easy thing to do wrong if somebody has taken it off.

 

[chrisspaulding]

Thanks to all for the thoughts, feedback and direction. I am going to pull the pump and send it off to be rebuilt.

Delaney, I'm working on getting the tach working with the 1HZ/1HDT motors. I'll post a write up when I'm through getting it all sorted.

Chris

 

[chrisspaulding]

Hello all,
Sent the injector pump to Thompson Turbo in Oklahoma City. Worked with Everett Stacy, a very nice and extremely knowledgable gentleman.
They just finished rebuilding the pump. Found the governor was stuck, which explains the over-revving. The also replaced the head and rotor. Bad fuel and sitting contributed to problem. Looking forward to getting the pump back on the truck and the engine up and running!
Chris Delancy, thank you for sending me to these guys. They were great to work with!

 

[Dave 2000]

Nice to see a follow up post.

regards

Dave