p0300 uphill

[mightybeet]

got p0300 again this time going uphill for a good distance. engine started to lose power so i pulled over for a bit, watched it idle, and then drove off again.

first time it happened was going uphill from a stop light when p0300 appeared. got home, idled funny in park and eventually stalled. started fine with normal idle.

i do feel a veryvery subtle hesitation/sputter at about 50+ mph and feel it more going uphill or with load on engine.

known things:
- 04 jeep liberty, 3.7l 6 cyl., 316K+, burns a lot of oil, needs a new oil filter.
- p0300 only, no other codes.
- starts normal, no hard starts.
- stable/flat idle at stop while in drive.
- coils and spark plugs have about 16k miles.
- tried making faces while hood was up.
- transmission is running with o/d off.

 

[ltd02]

got p0300 again this time going uphill for a good distance. engine started to lose power so i pulled over for a bit, watched it idle, and then drove off again.

first time it happened was going uphill from a stop light when p0300 appeared. got home, idled funny in park and eventually stalled. started fine with normal idle.

i do feel a veryvery subtle hesitation/sputter at about 50+ mph and feel it more going uphill or with load on engine.

known things:
- 04 jeep liberty, 3.7l 6 cyl., 316K+, burns a lot of oil, needs a new oil filter.
- p0300 only, no other codes.
- starts normal, no hard starts.
- stable/flat idle at stop while in drive.
- coils and spark plugs have about 16k miles.
- tried making faces while hood was up.
- transmission is running with o/d off.

Stumped but watching.

 

[kage860]

If I was a betting man I'd say you have a fuel delivery problem. You're "ok" with a low fuel flow requirement but when you put the pedal down (uphill or high speed) the problem is showing up in all of your cylinders. So I'd try either the fuel filter or fuel pump. If you have the funds to spare you can change both and get it finished, if funds are low you can start with the filter. You can always have one person check the fuel pressure while a second person revs the engine to verify it.

 

[kage860]

I found you a video showing how to access the fuel filter and the fuel pump.

https://www.youtube.com/watch?v=e47jXehVWo4

 

[libertybob]

If I was a betting man I'd say you have a fuel delivery problem. You're "ok" with a low fuel flow requirement but when you put the pedal down (uphill or high speed) the problem is showing up in all of your cylinders. So I'd try either the fuel filter or fuel pump. If you have the funds to spare you can change both and get it finished, if funds are low you can start with the filter. You can always have one person check the fuel pressure while a second person revs the engine to verify it.

Agree. Once had a Chevy S10 that would randomly lose power then run normally. Turned out to be failed fuel pump.

 

[mightybeet]

If I was a betting man I'd say you have a fuel delivery problem. You're "ok" with a low fuel flow requirement but when you put the pedal down (uphill or high speed) the problem is showing up in all of your cylinders. So I'd try either the fuel filter or fuel pump. If you have the funds to spare you can change both and get it finished, if funds are low you can start with the filter. You can always have one person check the fuel pressure while a second person revs the engine to verify it.

thanks, i think that is a good approach. whether its the filter or pump something fuel is going on. seeing more dew in the morning with the change in the weather so i am wondering if condensation is getting in there(if that is possible).

the misfires also ate a lot of fuel. i floored it several times going up hill letting the CEL flash and scream all it wanted and eventually started to feel some power come back. CEL went away last night. added some techron and fuel. this morning i was heavy on the gas the exact areas the p0300 came up and power was normal. no CEL.

the code is stored so i ll have my mechanic take a look if anything else comes up.

 

[kage860]

It's good you're going to get it checked, its a PITA if your fuel pump goes and you get stuck on the road. Have them check with a pressure gauge before you spend money on replacing parts.