About a month ago my truck started to die occasionally. When it does this the engine dies but all lights/other functions stay operating. I can restart it but sometimes this takes many tries. Also, sometimes when I restart it dies immediately and needs to be restarted several more times. Sometimes it seems to run fine after restarting but when I put it in gear it dies again.

This is very intermittent - I can go several days without problems and then it will happen 2-3 times in the same day. It happens at any time - first startup, while driving, after running for several hours - there is no clear pattern that will cause the shutdown.

I pulled a code for low fuel pump voltage - cleaned and rechecked the fuel pump ground and it was fine - decided that the pump was on its way out and replaced (did a fuel filter at this time too). This doesn't seem to have helped although the code is gone. I also thought it could be due to an alarm that was installed poorly - I removed the alarm, resoldered any wires that were cut, and they all check out fine now. Checked firing order and it's fine, pulled the distributor cap to check if the bushing was shot but there is no free play side to side with the shaft but there is about 3-5 degrees of rotational play. Coil doesn't have any carbon tracking or anything else to indicate a problem with it. Went to check timing earlier this afternoon but couldn't find the timing mark. (any idea where it is?)

Where do I go from here? Some other things, may or may not be related, engine runs a little rougher than I think it should, fuel economy seems kinda low too at ~14hwy/10city.

Thanks for your ideas!

 

I should also mention that it cranks about 5 seconds on cold startup in the mornings, after that initial startup it fires up on the first crank the rest of the day. I'm guessing fuel pressure regulator leaking down pressure overnight. Good guess or not?