Mechanics

RUNS ROUGH WHEN STARTED IN HOT TEMPERATURES, AND ENGINE IS HOT.

1995 Jeep Grand Cherokee • 19,000 miles

My 1995 Grand Cherokee runs fine when it's cold, or the weather is cold. Lately, it has been near 100 degrees most of the time where I live. After driving the car someplace, if I shut it off for a few minutes and then re-start it, it will shake, rattle, and roll until I clear the engine. It's acting like a vapor lock. If I park it (when hot) and then open the hood for a few minutes, it will start and idle fine. Obviously my problem is heat related, because when I allow the heat to dissapate, the problem goes away. Today, it was around 105 degrees out and for the first time, it started doing this while it was left idleing as I loaded items in the back. It started shaking, and then blowing a large amount of blue smoke. After getting in it and driving it for a few blocks, the problem cleared itself and all was fine. This doesn't seem to happen on days when the temperature is below about 75 degrees. Any ideas?
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Theskymarty
July 24, 2012.



Blue smoke usually means your burning oil somewhere, check your oil and see where your levels are

Tiny
MichaelSmithey
Jul 24, 2012.
Also what size engine and how hot is your jeep getting

Tiny
MichaelSmithey
Jul 24, 2012.
Scan for codes and check fuel pressure 31psi w vacuum line disconnected and 39-42 with connected at idle

Hmac300
Jul 24, 2012.
Sorry, I forget to mention the engine size. It's a 4.0 six cylinder. It's definitely not an oil burning problem. As again, it's intermittent and only on HOT HOT days, and then clears out immediately. The fuel pressure is fine. Checked it yesterday. The engine temp is fine, or within limits. The engine is not trying to overheat while driving.

Tiny
Theskymarty
Jul 24, 2012.
What is fine on fuel pressure? It needs to be within the specs. Check your crank/cam sensors for to much resistance or poor connections

Hmac300
Jul 24, 2012.