'02 Frontier rough running - distributor?

Why did you immediately condemn the distributor? Is the check engine light on? When it dies... can you restart immediately? Any other symptoms present? Idle speed changes? Other?

I didn't condemn the distributor immediately. In fact I am still somewhat skeptical but am prone to give in to the status quo because of time constraints. I am an ex-mechanic of 20 years. A close friend is an auto mechanics teacher at the local community college. We have discussed the symptoms at length. His opinion and others equally or less qualified have suggested that the distributor is a likely culprit - possible the pickup or coil? (still waiting to hear from Nissan mechanic friend's opinion).

Some of the facts:

- runs perfect in the AM when first started

- as it warms up, missing gets worse and worse (envision driving normally for a mile or so before it starts missing)

- eventually will not start at all after stalling

- engine light is ON, but possible only because I have disconnected sensors while the engine was running (O/2, temp, etc)

- it will not idle after it warms up

- "to me" when cranking the hot engine it feels and sounds like timing is way off, but I guess the distributor could just be firing erratically

- no smoke, black white or blue

- this started 20 miles after filling the tank (Chevron regular, no reason to believe it's water in the fuel or diesel since it runs fine when cold)

- "this problem" and steering box trouble both occurred within 2 months of last car loan payment (ugh)

Thanks again for your comments.

My 2-cents from a shade tree mechanic: I had this problem in my daughter's Sentra (see my recent posting). It is not much of an effort to check. If your Frontier have a distributor, take off the cap, and if the electronic inside are covered by a smaller plastic cover (in Sentra this is the case, held by two screws). Underneath you should see a small disk with many small square holes in a circular pattern and that has a photo sensor in one section of it. If you see/feel oil in this disk, thats the cause of your problem. Clean it up with a brake cleaner and see if your problem goes away temporarily. If that is the case, permanent solution is to replace the distributor or the shaft seal that isolates the oil from the camshaft to the distributor (assuming the bearings are still fine).

Although I could not detect oil on the disk or inside the distributor, replacement of the distributor did fix the problem. Thanks to all for your suggestions. Pete