Not a typical 7.3 hot no start...

co04cobra · Dec 20, 2014

Truck came in for a cold no start. Checked the hpop res and it was empty. Customer also wanted new GPs.

I got the truck running and test drove before pulling apart. And ran a CCT, per customers request, with no issues. Installed new GPs, and injector orings.

Truck starts fine cold, sounds and idles great, but once warm will not build over 250-275icp and 65 DC%. Also, will shut off on the road under heavy load. Will not build over 1100-1200icp.

I thought maybe an oring had got cut on install. However, I could see no leak around the injectors with VCs off. Pulled them back out anyway and they are fine.

Changed IPR with no change so then I swapped in a different pump and IPR...

Still no start hot. Starter and batteries good, and hpop resi is not draining overnight, also icp sensor is good.

Also, if I drain hpop resi it refills quickly.

What am I missing? Customer says the truck would restart fine hot before..

I also did Fords procedure of jacking the rear up and over filling with oil to submerge the pick up tube, with no change.

Derek@Vision Diesel · Dec 20, 2014

You removed the injectors and o-ring'd them and after this it created a no hot start?

I would put money on it that debris made its way to the poppet seat. Seen it many times, even on fresh injector installs.

With valve covers off watch the spill ports very closely while cranking it over while its hot.

co04cobra · Dec 20, 2014

Enough debris to stick it open and cause a hot no start?

The stuck injector should be pouring oil at the spout while cranking, when its hot, right?

I've installed a lot of 7.3 injectors and never had this happen. I did let a new employee install these, and oring them, but its at least the 4th or 5th set he's done, and watched me install dozens..

It has to be something like that though.

Arisley · Dec 20, 2014

Five seconds of not paying attention. Done deal, doesn't matter how many times you have done it.

From my experience, the first few times somebody does something, it will all go fine. After that, they think they know what to do and leave the instructions behind. Bad things happen and they pull out the instructions again, and all is well. Sorta like a good quarterback in his second full year.

gnxtc2 · Dec 20, 2014

When you changed the o-rings, were any of them damaged?

After my o-ring issue, I did an oil change and put 2k miles on it before leaving on my trip. I was towing my trailer and all of a sudden I lost ICP pressure. ICP will get up to 1200, IPR will go up to 75% then the CEL comes on, code 1211. After limping for approximately 100 miles, it cleared up by itself.

I am wondering if any debris got into injectors and/or IPR, causing them to hang open. The HPOP system uses unfiltered oil.

Billy T.
[email protected]

ghohouston · Dec 20, 2014

Derek@Vision Diesel said:
You removed the injectors and o-ring'd them and after this it created a no hot start?

I would put money on it that debris made its way to the poppet seat. Seen it many times, even on fresh injector installs.

With valve covers off watch the spill ports very closely while cranking it over while its hot.

Agreed

co04cobra · Dec 20, 2014

Derek@Vision Diesel said:
You removed the injectors and o-ring'd them and after this it created a no hot start?

I would put money on it that debris made its way to the poppet seat. Seen it many times, even on fresh injector installs.

With valve covers off watch the spill ports very closely while cranking it over while its hot.

Yes, since customer said it started fine hot before.

Arisley said:
Five seconds of not paying attention. Done deal, doesn't matter how many times you have done it.

From my experience, the first few times somebody does something, it will all go fine. After that, they think they know what to do and leave the instructions behind. Bad things happen and they pull out the instructions again, and all is well. Sorta like a good quarterback in his second full year.

I agree. He's young and works long hours. He is going to be a good wrench though. I was probably the same way when I was 20. This particular engine was very dirty on top so I'm putting a blame. I just need to figure it out to get it back to the customer.

gnxtc2 said:
When you changed the o-rings, were any of them damaged?

After my o-ring issue, I did an oil change and put 2k miles on it before leaving on my trip. I was towing my trailer and all of a sudden I lost ICP pressure. ICP will get up to 1200, IPR will go up to 75% then the CEL comes on, code 1211. After limping for approximately 100 miles, it cleared up by itself.

I am wondering if any debris got into injectors and/or IPR, causing them to hang open. The HPOP system uses unfiltered oil.

Billy T.
[email protected]

No, they didn't look that bad, more hard and brittle. I installed a new lower hpop resi gasket, but the old screen wasn't to bad.

ghohouston said:
Agreed

Have you had a hot no start from this? Were you able to easily spot the injector with the problem?

ghohouston · Dec 20, 2014

No, not personally, but the theory makes sense to me. I'd definitely pull the valve covers back after getting it hot and see what's going on. Who knows, maybe an o ring tore or blew out and the thick, cold oil is enough to keep it sealed a bit on startup. Don't remember if you stated or not, but is the hpop reservoir draining?

co04cobra · Dec 20, 2014

ghohouston said:
No, not personally, but the theory makes sense to me. I'd definitely pull the valve covers back after getting it hot and see what's going on. Who knows, maybe an o ring tore or blew out and the thick, cold oil is enough to keep it sealed a bit on startup. Don't remember if you stated or not, but is the hpop reservoir draining?

I understand the theory. Cut oring was my first thought, but I didn't find a leak while cranking with VCs off. I pulled the injectors back out anyway, but they were fine.

Resi not draining, with 2 different hpops and 3 different iprs.

ghohouston · Dec 20, 2014

co04cobra said:
I understand the theory. Cut oring was my first thought, but I didn't find a leak while cranking with VCs off. I pulled the injectors back out anyway, but they were fine.

Resi not draining, with 2 different hpops and 3 different iprs.

Was the motor warm when cranking?