Mechanics

2.3L 5 SPEED ROUGH IDLE PROBLEM AND CAN'T FIND SOLUTION

1996 Ford Ranger • 197,100 miles

I have a 96 Ford Ranger 2.3l 5 speed that has been having a rough idle problem for the past 2 or 3 weeks. My truck was running fine and then I had the CEL come on and the code was P0401 or EGR Flow is insufficient. I proceeded to change the EGR Valve and when I did this and started up my truck it was idling rough, so I put the old EGR back on and it didn't fix the rough idle problem. Since then I have changed the EGR Valve, EGR Vacuum Solenoid, EGR Sensor, IAC Valve, Air Filter, Fuel Filter, Upper Oxygen Sensor, Spark Plugs and Wires, and I have cleaned the MAF Sensor and the Intake Manifold and Throttle Body. When I took off the Intake Manifold the hole that goes to the EGR valve was completely clogged and since I cleaned it the CEL has not come back on. I have also had 2 instances of the CEL coming on and it being a Cylinder #2 misfire. Ever since I cleaned the Intake Manifold a week ago I have not had any CEL's. My truck is still idling rough. I took it to Ford and had them do a diagnostic on it and they told me that it wasn't misfiring and that it didn't have any codes stored in the computer. They also did a compression test, which said that cylinder #1 had a low compression by 1% and that cylinder #4 had low compression by 4%. They sent me on my way after telling me that it might be a slightly stretched timing belt and that they would charge $600 to replace it. What a joke! I am at a loss as to what might be the problem. I don't know how to check for vacuum leaks, but that may be the problem. The only other thing I can think of are the fuel injectors, which I don't know how to test. My truck's temperature gauge is also slowing going up and down between 1/4 and 1/2 when it is idling. Thanks for your help!
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Cardetailer18
April 20, 2013.



You need a dpfe valve for the 401 code.

As far as rough idle. Clean the throttle body, fuel pressure and idle air control

roy

ASEMaster6371
Apr 20, 2013.
You obviously didn't read the whole question. I have changed the DPFE otherwise known as EGR Sensor and I have changed the Idle air control and I have cleaned the throttle body.

Tiny
Cardetailer18
Apr 20, 2013.
My P0401 code is gone. It was a plugged up intake manifold port going to the EGR valve.

Tiny
Cardetailer18
Apr 20, 2013.