Jolting and Stalling during Acceleration

[SaintGeorge]

Hey all,

Having issues with the rig and would appreciate some as I am stumped.

CAR: D40 STX (2008) Thai Built

Engine: YD25DDTi, Diesel.

Checked, works good:

• ECU, general fuse box, ABS fuse box
• Engine oil
• Transmission fluid, clean and good level
• Coolant
• MAF
• Vacuum tubes

Explanation:

• RPM stable at idle always.
• Able to accelerate full throttle to 3rd gear 90% of the time.
• 60-80km rpm jumps around, sometimes stalls, struggles to maintain speed or accelerate further.
• Sometimes gears slip when trying to jump to 4th gear ONLY.
• Looks as if it’s trying to find the right rpm in relation to how much I’ve put the pedal down, jumps between different rpms for a few seconds.
• If I let go of the pedal at 60km+ the car will kick back and RPM will fluctuate, sometimes drop down <1000rpm and either stall or wake up.
• On rare occasions the car will barely have any issues but other times it will be dangerous to drive in.
• Burns rich when struggling.

I've checked with my OBD2 reader and i'm getting no fault codes.

Common rail pressure: ~32000kpa at idle, rpm at ~750.

Calculated load value: 18.4%

Intake manifold absolute pressure: 103.0 KPA

I'd appreciate help of any sort, and am happy to answer any questions.

Thanks,

George