1 HDT wont crank when hot (1 Viewer)

[V8Virgin]

I am sure someone on here has had a similar problem and can point me in right direction.
Recently done complete engine o/haul on 1hdt engine. 340 000 km on original engine. I had to get a donor engine block as original was badly corroded due to PO using water without coolant.
After O/haul engine starts and runs very smoothly no smoke no noises no heat build up good compression etc.
Problem is when the engine is hot it will not crank over. leave it to cool down for an hour or so and it will fire up on first crank again.
Have changed the starter motor, same result. Have changed the battery, same result. If i boost the battery it will crank when hot.
Am confused any pointers greatly appreciated.

 

[Ghostrider I]

Injection pump?

 

[Ghostrider I]

The water without coolant sounds very familiar.

 

[Squash]

24 or 12 volt?
Could be the fusible link wire from battery to starter relay which runs under wiper fluid container.
Try starting from underneath at the starter, just need the small solenoid wire and starter feed to make a momentary connection. If this works then look at the above wire or bypass this with a new fused line to the starter relay.
Had a 66 ragtop Cadillac ragtop in high-school which started so easily when cold. When hot it needed 24 volts, luckily it came with dual batteries.

 

[roscoFJ73]

You are most likely getting a voltage drop between battery and starter. The fact that when you add a battery and it cranks sort of confirms that. I would inspect and clean the battery cables at BOTH ends. Or maybe replace them.

 

[CaptBeardilocks]

I'm dealing with an intermittent issue similar to this. Brand new battery, cables, starter, everything. Do you get a hard click but the starter motor doesn't spin?

I would clean the connections at the starter and the main grounds. Then I would re-clean the battery terminals (they have a film on them brand new to keep them shinny at the warehouse. Then I would tighten the holy hell out of the terminals at the battery.

 

[V8Virgin]

Hopefully fixed........ cleaned all connections and terminals, tightened all connections to FT settings, still behaved the same.
Put in the biggest battery i could shoehorn into the battery box, a 125 Ah and that seems to have solved the issue for now..... fingers crossed.

 

[IanB]

If your problems persist, your plunger and contacts in the starter may be due for replacement.

 

[CaptBeardilocks]

If your problems persist, your plunger and contacts in the starter may be due for replacement.

Both of us were having this similar problem with new starters. Seems to be a resistance issue somewhere, unless new starters are commonly having points/plunger problems these days...

 

[IanB]

Both of us were having this similar problem with new starters. Seems to be a resistance issue somewhere, unless new starters are commonly having points/plunger problems these days...

Ah, I missed the starter was already replaced.

 

[roscoFJ73]

You need to test the voltage when cranking at the starter. Thats how auto electricians i have hired do it. You can keep trying other starters or other batteries but the problem will always be there.
Ive started 1HZ's with a higher compression ratio than a 1HD T with smallish car batteries no problems.

 

[CaptBeardilocks]

All my cables are brand new. I used 1/0 Welding cable. So there would have to be an issue with the bulk wire I used or...? I personally crimped the connections myself. Which means nothing. Lol. As my buddy say "Every time I look at a system on my truck I assume that the last idiot screwed it up, even if I was the last idiot."

 

[Squash]

If this is still 24v then try starting from the starter use a short jumper from + battery supply to small solenoid at starter. If she starts from here work your way up from the stater towards the battery.
My 81 uses 24v to start with the key and I can start her using 12v via a momentary switch.

 

[CaptBeardilocks]

I’m not sure about OP, but I have converted to 12v starter system.

 

[CaptBeardilocks]

I'm still fighting this issue. I get a HARD click on the solenoid when turning the key and that's it. But only about 30% of the time. The rest of the time it starts up perfectly. Seems to be completely random. Hot or cold engine. Having sat for a week or restart after driving a while. Sometimes a jumper pack works, sometimes it doesn't, which makes me believe that that's just luck. If I rock the ignition it will eventually spin the starter. Might have to rock once, might be 8-9x. It seems to be completely random.

Battery, 12v starter, and all wires are brand new.

I tested voltage drop on everything yesterday and it all checks out within spec on both the positive and negative side.

My best guess at this point is a faulty solenoid on the new starter. Unfortunately, being an HD-T in the USA means the starter came from Australia and returns are more than a little expensive. I might have to take it in locally to be rebuilt. I wish I had a spare starter to swap in, but they're hard to find stateside.

Any ideas, testing procedures, or other suggestions would be appreciated.

 

[Squash]

The 12 and 24 volt starter shares the identical housing. A decent shop will have no problem rebuilding.
Plus some dodge parts interchange if you are stuck.
Before you pull a perfectly good starter try some other options.
The Ford solenoid could be just what you need. Maybe an ignition bypass.

 

[Marioooooooo]

I am sure someone on here has had a similar problem and can point me in right direction.
Recently done complete engine o/haul on 1hdt engine. 340 000 km on original engine. I had to get a donor engine block as original was badly corroded due to PO using water without coolant.
After O/haul engine starts and runs very smoothly no smoke no noises no heat build up good compression etc.
Problem is when the engine is hot it will not crank over. leave it to cool down for an hour or so and it will fire up on first crank again.
Have changed the starter motor, same result. Have changed the battery, same result. If i boost the battery it will crank when hot.
Am confused any pointers greatly appreciated.

Hey brother, Where did you get the engine block for your 1-HDT? I am in search of one myself. Thanks.

 

[Dave 2000]

A weak battery, poor connection, poor solenoid contacts, can contribute to what you are experiencing, having recently replaced the engine, did you replace the engine to bodywork earth often missed when replacing an engine.

Correct jump starting means you would be connecting the negative to the engine, now the block and thus starter would be correctly earthed.

Regards

Dave.

 

[CaptBeardilocks]

Updating an old thread here just for anyone else having a similar problem. I solved this eventually by adding in a Toyota starter solenoid/relay. Turns out the big diesel starters need more than the weak 12v signal from the ignition key that the 1FZ uses. Starter relay wired to the battery and going to the signal wire on the starter solenoid solved the problem for the last 25k miles.