Caterpillar 3126 (1WM Model) Help Needed.

I’m new here so my apologies for coming out the gate with some complicated bs. If anyone here has the experience and understands the difference with the 3126 1WM Serial number that was produced in 97-98 (the engine with the jumpers going from the oil rail to the injectors) and the normal 3126, please help.

This is a 97 Ford Dump truck. It came in with a normal Cat complaint, starts cold, then nice warm, it’ll only fire on ether. Without going into the long winded reasons for changing all
These parts, I’ll just say I know the procedure for this failure well but none of it has solved this issue. Here’s a list of everything that’s been done, can anyone think of what should come next? I’m so wore out on this thing that I’m having nightmares about it lol..

Replaced:
1. IAPCV
2. Fuel Filters
3. Oil
4. Heui Pump
5. Injector Seals
6. IAPCV Harness
7. Injection Actuation Pressure sensor
8. Fuel lines from Tank to separator
9. Timing Sensors
10. Timing sensor connectors

1. I have no Oil coming out around the injectors
2. I have engine speed signal
3. I have “active” codes but I do get a 164-11 when cranking then it goes away after cranking stops
4. I have ran it on a bucket of fuel
5. I have fuel pressure
6. But I have not been able to achieve more than 400psi cranking no matter how I try.

I have done so much that I may be missing some things but once it’s started, I have perfect heui pressure and it runs like a champ, until I cut it off. Any ideas? Thanks so much!

 

Yes, it requires 875psi of oil pressure to fire the injectors in a cat.

 

funny you should say that. Soon as I broke down and joined a forum to ask, I got back from lunch, removed the valve cover for the 10th time, misted it with ether
And let it run for about 10 minutes with the cover off and there she blows. Stupid ### oil jumper tube used on these 2 valve POS versions decided to reveal a crack on cylinder 4. FML. It’s been a long road..lol

 

Meaning I can’t even get to 400psi. Much less the minimum of 875psi. I think what you are referring to is when Troubleshooting a bad IAPCV known to some as an IPR, you dead head the pump to get full pressure, then unplug the sensor so the ECM defaults to 4200psi which tricks the injectors into firing. But even with that, if you can achieve something close to 800, the poppets won’t even open so the fuel can come in. I have no idea how I became the CAT guy around the shop but every day is a stout reminder as to why I’m loyal to Cummins. Lol