QuestionQUESTION: I have a 2001 Ford Escort with the 2.0 engine. Recently, the check engine light has come on and I am struggling to identify the problem. Here is a brief history of recent work on the vehicle.
Chk Eng light had come on a couple months ago and the car was running very rough. I discovered the PCV elbow/hose was badly torn and sucking a lot of air. I replaced the elbow hose and that solved the problem. It may be worth noting here that the parts house did not have the right diameter elbow so they sold me one that was close and provided a standard metal hose clamp to seal the hose. I have looked closely at this and it is definitely NOT leaking at all.
At that time I also changed the oil, spark plugs and the "pre-cat" 02 sensor since the vehicle was due for a smog test. I had the check engine light reset and the vehicle later passed smog no problem.
Now, the check engine light is back on and the vehicle is not running right again. At idle, the vehicle runs quite rough, bad in park,...worse in gear! However, if I press the gas pedal just enough to idle up a tad it does smooth out. Also, it runs pretty well while driving, just terrible on idle.
I had the vehicle scanned for codes and it came back showing "cylinder 4 misfire". This is odd since all of the plugs are still quite new and the vehicle just passed smog. I replaced the plug wires and there is no change. I pulled the plug to check for spark, and there is plenty of spark.
I don't think it is relevant but for the purpose of ruling things out you should know that we also replaced the fuel pump recently as it had failed.
Just to recap, the vehicle has:
New plugs
New Wires
New 02 sensor
New fuel pump
New PCV hose
If I listen closely, I thought I could hear the faintest of vacuum leak sound near the firewall side of the engine, but I searched as much as I could and came up empty.
HELP! Any ideas?
ANSWER: Two things come to mind quickly, first- what did you use for spark plugs ????? second- looking at the valve cover just behind it to the left you will see a black valve with a two wire connector going to it with two vacuum lines connected to it. disconnect this and plug both lines and let me know how it runs- this is a valve that controls the egr. sometimes they get stuck
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QUESTION: Thanks Brian,
I used Autolite plugs, # 5144 I think. I did locate what appears to be a black plastic valve that seems to resemble the one you describe. It does have a 2 wire plug and it had 2 vacuum lines attached, one is red and one is green. They are made of thin plastic with rubber elbows. When I disconnected these and plugged them with my thumbs, the idle definitely improves. What do I call that valve? Do I replace it all together?
It is actually mounted on the firewall just about center of the vehicle, behind the exhaust manifold.
Thanks for your time and help,...I think you may have just solved my problem!
AnswerThat being the case which, was not an uncommon concern, you want to replace it. it is called and e.v.r. valve.. ( egr vacuum regulator ) it controls how much exhaust gas is being sent back to the engine for emissions reasons- it also cools down combustion temperatures in the cylinders. this valve is only supposed to open at a steady cruise but if stuck slightly open- will cause the rough idle you described. the fact that you disconnected it and plugged both ends and the idle smoothed out tells me it is partially stuck open. perfect job with your mechanical skills as this is how we diagnose it as well. get back to me. this part is fairly inexpensive but, should you get quoted a high price go to rockauto.com.. incredibly low prices.. take care -b-
