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Dodge Repair/intermittent shutdown problem: 3.3L '99

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QUESTION: I thought that you said in the previous reply that the voltage between violet/white and black/light blue should also drop to less than 2V, once the engine is started. Since, in my case, it was staying at 5V after starting the engine, I thought that might be a sign of MAP sensor going bad.

Regarding the O2 sensors. I believe there are 3 sensors in this engine in the US model: two upstream, one on each exhaust manifold and one downstream after the catalytic converter. The Middle Eastern model has only one (if present, I cannot see it clearly) O2 sensor located on the front (of the car) exhaust manifold. I am sure that there is none on the rear exhaust manifold (as I had a problem in the past with its lose/unused wiring harness). In addition, there is no catalytic converter and therefore no sense of downstream O2 sensor. How can then we interpret the 0.29 and 4.7V on the upstream and downstream sensors?
Thanks again.

ANSWER: Hi Shafique,
No, the 5v between the violet/white and the black/light blue is the operational supply voltage for the sensor and should remain constant no matter what the engine is doing.
As to the oxygen sensor(s), I don't have any information on how the middle eastern model is equipped. On the U.S. there is one sensor on the rear manifold and one sensor after the catalytic converter. If you don't have a converter and the vehicle didn't have one to begin with then I would not know what to make of the reading shown for the downstream sensor. It is no doubt irrelevant.
Roland

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QUESTION: About two years ago, the fuse for engine in the fuse box under the hood used to blow. At the end, I found that the harness for O2 sensor was damaged and the wire was touching the body causing short-circuit. The O2 sensor was never there. I got the loose harness points taped up. I remember at that time, I asked the dealership and based on  VIN, he told me that there is only one O2 sensor. I will investigate it further.

While searching online blogs, l came to know about this instrument cluster loose solder joint problem. I will look at it next weekend.

I have one question regarding EGR. Although I have cleaned it and the stem was moving freely, but is there a chance that it actually needs replacement?

ANSWER: Hi Shafique,
If the valve was so gummed up inside such that although the stem moved freely that it didn't close tightly to a dead stop by means of the internal spring-action, then yes that could cause the engine to die when you slow down or accelerate. So test the action to determine whether it seems to come to a full hard stop or not. If not then remove it and clean out the interior.
Thanks for the rating/nomination.
Roland

---------- FOLLOW-UP ----------

QUESTION: I am still trying to solve the same problem!
I have noticed something further that may point to something.

Normally, when the van is started, the RPM reaches 1500 rpm while cranking and then (once the engine is started), it reduces smoothly to the idle speed (~700-800 rpm). I have noticed that sometime, this is not happening. On those occasions, the RPM reaches 1500, then dips to ~500 rpm and then increases to 700-800 rpm. At that time, while idling and in P, if I turn on the AC, the rpm drops by 100-200 rpm, i.e. the system does not make any changes to maintain the idle speed of 700-800 rpm. This normally happens when I return to start the van in, say 30 minutes or less. At other times (engine cold in the morning or engine at normal operating temperature), this sudden drop does not happen.

Does it point to anything specific malfunctioning?

Thanks

Answer
It may indicate that the idle air control passageway is dirty or the pintle which varies the opening of the idle air passageway is a bit sticky in its action. Have you cleamed the throttle body throat and both sides of the throttle plate and the idle air passageway on the side of the throat using a solvent? That is what would be suggested by your observation, Shafique.
Roland

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Roland Finston

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Get a Free Fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

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I have do-it-yourself experience (50+ years) and a library of 100 1982-2012 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.

I was voted "Top expert" from 2010-2015 here at AllExperts, and have answered 20,000+ questions.

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Five decades as a 'do-it-yourselfer' on domestic and imported cars

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Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)

Education/Credentials
Degrees in Physics/bruised knuckles.

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"Top expert" of 2010, 2011, 2012, 2013, 2014, and 2015 here at Allexperts. Quickest "average response time" at Allexperts (currently no. 1).

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