1999 Dodge Ram Rough idle

  • 1999 DODGE RAM
  • V8
  • 2WD
  • 70,000 MILES
I have a 1999 Dodge Ram 1500 5.2L V8.

A year ago at 61,000 miles I had to have the heads replaced due to the engine overheating. After having the work done I had to change the alternator because the engine was running horrible.

After replacing the alternator, the engine ran a lot smoother, but still had a small rough idle. The rough idle was more present when the truck was in gear and not moving. I then started getting a code stating that there was a Cylinder #4 misfire.

After replacing the # 4 fuel injector, all spark plugs, wires, distributer cap, rotor and ignition coil the engine ran better, but still had a slight rough idle.

After replacing all sensors on the throttle body and then cleaning the throttle body, the engine ran like new. Just a few months ago the rough idle started again. I once again got a Cylinder #4 misfire.

This weekend I replaced all 8 fuel injectors, changed all the spark plugs and cleaned the throttle body again. The rough idle is still there.

When I start the engine, it revs up high, then idles back down to normal, When I put it in gear, the entire truck shakes a little and seems hesitant.

It seems as though the rough idle is more present when sitting at a stop light in gear. When not in gear the rough idle is not as bad.

I am running out of options. I just rolled over to 70,000 miles.
Do you
have the same problem?
Sunday, March 15th, 2009 AT 7:10 AM

1 Reply

I have a 1999 Dodge Ram 2 wheel drive 5.2 v8, it did not want to idle. I ran voltmeter tests on the sensors, found out the map sensor was sending a variable voltage signal which did not coincide with the manifold pressure at all. I replaced the map sensor and it idles like a champ. The Haynes repair manual helped me diagnose this problem, it is worth the money.
Was this
Tuesday, March 17th, 2009 AT 6:19 PM

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