Poor idle when I come to a stop or slowly turn
lrizzo2001
10-05-2010, 10:51 AM
I have a 94 JGC Laredo 4.0. After recent work, the engine will idle very low when I come to a stop sign or traffic light the the point of almost stalling. I can put the truck in Neutral and it's fine. It's never stalled on me, but don't like letting the idle get that low so I just put it in N. It will also sometimes happen when I'm making a slow turn, like a U-Turn. Another thing I've noticed is that my Voltage Meter on the dash will drop from 14 to 13 when I turn certain things on like the Rear Defroster and I will at the same time see the idle drop slightly.
I've replaced the TPS and the IAC. I was told that the TPS might need to be reset by the dealer or a good GST? scanner? Never heard of this, and I can't find anybody that has a diagnostic tool for the older model cars to see if anything else is going on. I don't have a check engine light.
Here's a brief history on recent work done.
1. Truck had crank no start on first couple of tries
2. Replaced crankshaft sensor
3. Replaced Fuel Pump
4. Replaced Coolant Temp Sensor
5. Replaced PCM
6. Replaced TPS
7. Replaced IAC
8. Replaced Spark plugs, wires
9. Replaced Dist Cap and cleaned rotor.
Do any of these steps raise any red flag regarding my new low idle problem?
I've replaced the TPS and the IAC. I was told that the TPS might need to be reset by the dealer or a good GST? scanner? Never heard of this, and I can't find anybody that has a diagnostic tool for the older model cars to see if anything else is going on. I don't have a check engine light.
Here's a brief history on recent work done.
1. Truck had crank no start on first couple of tries
2. Replaced crankshaft sensor
3. Replaced Fuel Pump
4. Replaced Coolant Temp Sensor
5. Replaced PCM
6. Replaced TPS
7. Replaced IAC
8. Replaced Spark plugs, wires
9. Replaced Dist Cap and cleaned rotor.
Do any of these steps raise any red flag regarding my new low idle problem?
rhandwor
10-05-2010, 08:19 PM
I have a 94 JGC Laredo 4.0. After recent work, the engine will idle very low when I come to a stop sign or traffic light the the point of almost stalling. I can put the truck in Neutral and it's fine. It's never stalled on me, but don't like letting the idle get that low so I just put it in N. It will also sometimes happen when I'm making a slow turn, like a U-Turn. Another thing I've noticed is that my Voltage Meter on the dash will drop from 14 to 13 when I turn certain things on like the Rear Defroster and I will at the same time see the idle drop slightly.
I've replaced the TPS and the IAC. I was told that the TPS might need to be reset by the dealer or a good GST? scanner? Never heard of this, and I can't find anybody that has a diagnostic tool for the older model cars to see if anything else is going on. I don't have a check engine light.
Here's a brief history on recent work done.
1. Truck had crank no start on first couple of tries
2. Replaced crankshaft sensor
3. Replaced Fuel Pump
4. Replaced Coolant Temp Sensor
5. Replaced PCM
6. Replaced TPS
7. Replaced IAC
8. Replaced Spark plugs, wires
9. Replaced Dist Cap and cleaned rotor.
Do any of these steps raise any red flag regarding my new low idle problem?
Low voltage will cause running problems. Advance Auto and Auto Zone will also test the charging system for you free. Any hoses loosevon the intake will also cause running problems. Spray along the intake with WD40 and if it idles better fix the leak.
I've replaced the TPS and the IAC. I was told that the TPS might need to be reset by the dealer or a good GST? scanner? Never heard of this, and I can't find anybody that has a diagnostic tool for the older model cars to see if anything else is going on. I don't have a check engine light.
Here's a brief history on recent work done.
1. Truck had crank no start on first couple of tries
2. Replaced crankshaft sensor
3. Replaced Fuel Pump
4. Replaced Coolant Temp Sensor
5. Replaced PCM
6. Replaced TPS
7. Replaced IAC
8. Replaced Spark plugs, wires
9. Replaced Dist Cap and cleaned rotor.
Do any of these steps raise any red flag regarding my new low idle problem?
Low voltage will cause running problems. Advance Auto and Auto Zone will also test the charging system for you free. Any hoses loosevon the intake will also cause running problems. Spray along the intake with WD40 and if it idles better fix the leak.
lrizzo2001
10-08-2010, 09:19 AM
Problem Solved. I just simply removed the air tube on the Map Sensor and put it back on again.
Godzilla.vs.Jeep
10-08-2010, 04:08 PM
Glad you got it sorted, symptoms described reminded me of when I had a bad fuel pump.
Problem Solved. I just simply removed the air tube on the Map Sensor and put it back on again.
Problem Solved. I just simply removed the air tube on the Map Sensor and put it back on again.
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