aschafer14
New member
So I just purchased this FG649 with the 4D34T and am trying to figure out a low power issue. I know these aren't built for speed but sit feels really sluggish. There is a significant amount of blowby, the oil cap bounces right off with the oil cap test. I hooked up a boost gage and I'm maxing out at 11psi under full load. I did a compression test and leak down test and both seem fine (see results below).
I pulled the injectors and the pop off pressure is low so I'm wondering what some new injectors might do.
I also borescoped the cylinders and everything looked good except for #1 where there was some wear on the cylinder wall and some strange discoloration around one of the valves on cylinder #4.
I tested the pop off valve and it releases at 22-25psi and the wastegate actuator starts to open at about 15psi and fully open at 20psi.
I plan on sending some oil out to get tested but other than that I'm running out of ideas. Any help would be much appreciated. Has anyone replaced injectors and noticed a big improvement?
I pulled the injectors and the pop off pressure is low so I'm wondering what some new injectors might do.
I also borescoped the cylinders and everything looked good except for #1 where there was some wear on the cylinder wall and some strange discoloration around one of the valves on cylinder #4.
I tested the pop off valve and it releases at 22-25psi and the wastegate actuator starts to open at about 15psi and fully open at 20psi.
I plan on sending some oil out to get tested but other than that I'm running out of ideas. Any help would be much appreciated. Has anyone replaced injectors and noticed a big improvement?
| #1 | #2 | #3 | #4 | |
| Compression Single Burst (psi) | 140 | 125 | 140 | 140 |
| Compression Constant Cranking (psi) Spec 370psi, minimum 285psi | 342 | 345 | 345 | 350 |
| Leak Down % Lost @80psi | 8 | 9 | 4 | 8 |
| Injector Pop Off Pressure (psi) Spec 3130psi | 2900 | 2900 | 2950 | 2700 |
