I have a 2005 KJ Renegade 2.8 CRD with 109000kms on the clock. My problem: When the engine is running hot (specially after sitting in traffic jams), and I get to accelerate on open road (simple steady acceleration), the engine will give a 1/2 second hiccup-jerk (only way I can describe it), it's as if it's trying to change down from Drive to 2nd or 1st gear. Very scary, as it is as if the vehicle wants to stop, but doesn't. It will hiccup-jerk violently for about 1/2 sec and then continue. If it is running really hot, it may do this another few times, always and only when accelerating. It never shows this symptom when cold. At first, I used to be worried to see the water temp running close to the red line after being stuck in traffic, but the fan kicks in and the water levels are fine. The 'hiccup' issue is very worrying. Desperate for advice/suggestions.

Sounds like an air-in-fuel issue to me. Try priming and bleeding the fuel filter and/ or changing the fuel filter.

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In this war of lines, so many have been crossed. Where will it all stop?

2006 Deep Beryl Green CRD Sport *SOLD 1/22/12*
Provent, V6 Airbox, Fumoto, Samcos, GDE ECO & TCM Tune, Euro JK TC, Magnaflow Catback
245/70/16 Destination A/T's
Boiler's Radiator Skid Plate
Jeepin' By Al 2.5 inch Adjust-A-Strut Lift, JBA Gen 4.5 UCA's (6/5/10)

To me it sounds like you have forthcoming EGR issues. The hiccup/jerk you feel I'm betting is actually misfire from the EGR valve not closing fast enough and the fresh air mass into the engine is too low to sustain stable combustion. Since you noted your odometer in km versus miles, I take it you're not in North America? This could lend itself to why you haven't set a Check Engine Light yet.

Unplug the MAF sensor on the air cleaner assymb and if your troubles end, you'll know it was the egr valve.

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06 CRD Limited. IMII, GDE TCM, Carter transfer pump, Upgraded oem primary, 2 micron secondary, 3 inch mandrel straight pipe.
Transgo shift kit, EHM, fcv butterfly removed, egr plated off. 19 3/8 solid flex fan, no electric fan, 10k lb aux trans cooler.
Frankenlift II, Mopar skids, allj's rails, 235/85 km2 on stock rims