'91 pathfinder timing issue

[SLEEPER 86]

never seen this one before,4WD, engine family; MNS3.0T5FBF1 engine runs great when cold, but as it starts to reach operating temperature, it starts to sputter sporadically. this gets worse until the engine starts backfiring out the intake and exhaust, bucking, and finally dies. i checked the ecu codes and got a 21 (interruption in ignition signal). replaced a completely wasted dizzy cap and rotor (cap was missing the contact pin that touches the rotor!), that seemed to clear the code. i replaced the fuel filter because the random sputering made it seem like water in the gas. still did it. broke out the timing light and it looks like the marks are around 3:00 instead of 12:00 where they should be! can a timing belt jump time like that? the marks look very stable after about 5 minutes of run time but i heard it starting to sputter and pop again so i shut it down. could this have something to do with the crank sensor in the dizzy? once the engine cools off, it runs great again any ideas would be greatly appreciated! thank's in advance Eric B

[driftingmy240sx]

yes a timing belt can jump time but it would run piss poor all the time. does this problem occur at idle and cruise or just cruise? i have seen the distributors on these cause things to go crazy when the car warms up.

[SLEEPER 86]

idle and cruise, i'm really leaning towards the crank angle sensor that's built into the distributor. i was reading on here somewhere that if it goes out it throws the timing off by 120 degrees. that's about right where i'm at. what worries me is the potential valve/piston contact when the timing is that far off. now what confuses me is the haynes manual says the crank angle sensor is only replaceable by swapping the whole distributor, but advance auto sells the crank angle sensor seperately as a replacement part? is it that tough to swap one out?
Modified by SLEEPER 86 at 3:21 PM 4/24/2008

[driftingmy240sx]

the timing issue is not mechanical timing but spark timing. i would replace the whole distibutor assm not just the internal sensor.