Looking for answers

[C3rv32a2]

Hello to all,

I'm a first time user.

I owned a Jeep Liberty 2002 4W 3.7L

I has been working great. but a few days ago i had to use it for a trip. On the road when there was a long downhill or a steep. Check engine light started to blink. When I came out of the downhill the check engine light stopped blinking but it stood on.

Some time depending of the downhill when I cam out of it and press gas again it did not respond and started to shake a little. I pulled over, turned off the engine, turn it back on and like nothing happen. The vehicle responded great, check engine light keep on.

I when in to an auto zone so they can scan it and the code that comes up is P0300.

After 2 or 3 days of driving around the check engine light turned off, when I got back from the trip same thing happened again on a downhill or steep.

Any ideas on what could me the problem?

 

[CalcityRenegade]

Hello to all,

I'm a first time user.

I owned a Jeep Liberty 2002 4W 3.7L

I has been working great. but a few days ago i had to use it for a trip. On the road when there was a long downhill or a steep. Check engine light started to blink. When I came out of the downhill the check engine light stopped blinking but it stood on.

Some time depending of the downhill when I cam out of it and press gas again it did not respond and started to shake a little. I pulled over, turned off the engine, turn it back on and like nothing happen. The vehicle responded great, check engine light keep on.

I when in to an auto zone so they can scan it and the code that comes up is P0300.

After 2 or 3 days of driving around the check engine light turned off, when I got back from the trip same thing happened again on a downhill or steep.

Any ideas on what could me the problem?

That code is for misfires. I would check you're spark plugs and coil packs. I have had coil packs fail and cause my Jeep to bog and have no power. Spark plugs and coil packs are very easy to inspect/replace.

 

[C3rv32a2]

Thanks,

Before the trip I replace the spark plugs. Forgive by ignorance but if it was a problem with I spark plug or coil pack should it fail more often or keep the engine check light on and not just only on a downhill?

 

[tinyejp]

The hill could just be coincidence. I would try to replicate the conditions a few more times to be certain if the terrain makes a difference. If it is consistent and repeatable, I'd start looking for a loose or intermittent connection. Could be something is coming loose when the Jeep is in a certain orientation.

Check/clean battery connections. They can cause all sorts of funny things to happen, and it's an easy place to look.

 

[libertybob]

Misfire

I had the same thing happen to me with the same symptons. #6 and #3 cylinders both set misfire codes and the cylinders are on opposite banks. I hypothesize it was moisture in a tank of gas as I had just filled up. After shutting the engine down and restarting, everything was normal. I erased the codes and have driven over 600 miles since with no repetition. Could you have had moisture in your gas?

 

[C3rv32a2]

Hello libertybob and tinyejp

This happen to me closing in to Las Vegas coming from phoenix so there is a lot of ups and downs. Each time I got a long downhill same thing happen. I stayed in Las Vegas for a few days and after 2 days check engine light went off by itself.

When I returned same thing happen to me on the downhills and only on downhills, going up I had no problem, liberty responded correctly.

If I have moisture on the as tank I do not know, how can I check and repair this?

Before I left I made an oil change, oil filter and air filter change, also I changed the spark plugs, I put in NGK iridium, they were recommended.

 

[LibertyTC]

Always use what is recommended in the under the hood sticker! (gap them right too)
Jeep likes copper core plugs!
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The Jeep may not like those Iridium plugs at all !!
If you want to see it run well....:gr_grin:
54026[/ATTACH]"]

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Fuel related ethanol moisture problems try Star Tron Link: http://www.starbrite.com/item/star-tron-gasoline-additive?category_id=587

 

[ouroboros]

Don't listen to what most parts peddlers tell you... Going to the more precious metal or 'better' sounding spark plug doesn't mean it's necessarily better for your vehicle. We just had a lengthy 'argument' over this. There's some things that those bastards at Chrysler got right and one of them is the correct plugs for your vehicle! :waytogo: Like I said in that other thread though.. The answer is obvious, just pop your hood!