2004 Jeep Liberty won't start, cranks once then nothing

[DominaAtia]

Noticed that my Liberty (3.7L) was acting sluggish accelerating. Caught a weird smell and a little whitish burning smelling smoke coming from right front wheel. Based on smell, I started checking fluids. Oil was really low, so I got it topped up, and let it rest for a couple minutes. Turned key, and it had trouble starting. That traditional "cough" sound that cars make when you start them? Yeah...that happened once, and nothing. Tried a couple more times, engine turned over. I let it idle for a minute to let that fresh oil get around a bit, and it sounded perfect. Headed home, noticed some mild lagging in the acceleration but smooth idle, no knocking or unusual sounds/smells. Parked it and cut the engine. Waited a minute or two and out of curiosity tried to start it again. Turn key, single "cough", then nothing. It won't start.
Wth happened here? Any ideas? Battery and all fuses recently replaced. Oil and other fluids are good. No smoke or smells from anywhere, and temp gauge showed and held the usual expected reading when I first got it to kick over and run.
Could this be one of the pumps or some such? I don't know from serious engine stuff. I can check and maintain the basics, I can ID certain obvious serious issues like belts, fan, hoses, etc and I found nothing. Does this sound electrical, or motor to y'all?

 

[Scoot]

It might be something with the fuel pump, when you turn the key on if you stick your head by the gas tank do you here the fuel pump priming? It might be the relay

 

[osbro168]

Noticed that my Liberty (3.7L) was acting sluggish accelerating. Caught a weird smell and a little whitish burning smelling smoke coming from right front wheel. Based on smell, I started checking fluids. Oil was really low, so I got it topped up, and let it rest for a couple minutes. Turned key, and it had trouble starting. That traditional "cough" sound that cars make when you start them? Yeah...that happened once, and nothing. Tried a couple more times, engine turned over. I let it idle for a minute to let that fresh oil get around a bit, and it sounded perfect. Headed home, noticed some mild lagging in the acceleration but smooth idle, no knocking or unusual sounds/smells. Parked it and cut the engine. Waited a minute or two and out of curiosity tried to start it again. Turn key, single "cough", then nothing. It won't start.
Wth happened here? Any ideas? Battery and all fuses recently replaced. Oil and other fluids are good. No smoke or smells from anywhere, and temp gauge showed and held the usual expected reading when I first got it to kick over and run.
Could this be one of the pumps or some such? I don't know from serious engine stuff. I can check and maintain the basics, I can ID certain obvious serious issues like belts, fan, hoses, etc and I found nothing. Does this sound electrical, or motor to y'all?

 

[osbro168]

Probably right side valve cover leaking oil and it messed up your starter. Check for power at the starter when its not starting.

 

[slowcrawlerZJ]

It can be a fuel pump and/or it could be a cam position sensor and/or crank position sensor that are both on the right side of the engine. Relatively cheap and easy to change both at the same time. One of those can be your culprit if they have never been changed. They will cause some of the problems your describing.

 

[KJowner]

When you say won't crank do you mean the starter isn't turning the engine? Or do you mean it won't fire when it's spinning over on the starter.