'89 Cherokee 4.0L six, nothing custom, 210k miles, runs like a champ.

It's taken incrementally longer to start over the last few weeks but never all that long. Today it just cranks and cranks and doesn't catch.

The fact that it otherwise runs fine, and that it has only lately taken a little longer than usual to catch, should be clues. Might the coil fail in that manner? If fuel system, wouldn't I see symptoms while running? Not much of a mechanic but paying someone to fix this today isn't an option.

Thanks!

 

Could be a lot of things. When was the last time your Crankshaft Position Sensor (CPS) was changed? Usually, you will have longer and longer crank times as the CPS goes bad. Could also be a fuel issue. Do you have a fuel pressure gauge to measure fuel pressure?