1990 Chrysler New Yorker Engine runs rough when cold.

1990 CHRYSLER NEW YORKER
130,000 MILES • 6 CYL • FWD • AUTOMATIC
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MCISME
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Hello. My car starts up fine when its cold but after a few minutes it runs rough. When the car is warm i dont have any problems.

For instance: Ill start the car. Leave and get about 1/4 mile down the road and then the car starts running rough and backfiring. I usually give it the gas and it will stop. It only does this when the car is first started up or when the car is fairly cold still after driving.

I have changed the fuel pump/strainer,Fuel filter and coolant temp sensor. I was told it might be another sensor.

Any help would be appriciated.

Thanks.
Mar 23, 2009 at 10:00 AM
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JACOBANDNICKOLAS
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Has the check engine light come on?
May 11, 2009 at 7:21 AM
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MCISME
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No check engine light. I had the fuel pressure checked and it was great. I also changed the tempurature switch but i was told that is just for the guage, which i found to be true that the temp guage runs off the temp switch, not sure if anything else runs off the temp switch though.
May 11, 2009 at 9:18 AM
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JACOBANDNICKOLAS
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There is a temp sensor that tells the computer how rich to run the fuel mixture based on temp. Cars with fuel injection don't have a choke like the old ones. If that is ok, I would check for vacuum leaks.
May 11, 2009 at 12:04 PM
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MCISME
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Yeah the coolant temp sensor is for the fuel rich/lean, that was replaced. The temp switch is for the guage.

Also i want to point out that sometimes when i first start the car it will run fine for a minute or 2 and then runs rough and you can hear the air intake sucking air loudly. The idle will go up and down also. This has not happened in a while.


I will check for Vacuum leaks and get back to ya. As far as i know there wasnt any but ill double check.

Thanks
May 11, 2009 at 1:03 PM
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JACOBANDNICKOLAS
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Check the EGR valve too for it sticking. Timing and vacuum leaks are good for causing backfires.

Let me know what you find.

Joe
May 11, 2009 at 1:32 PM
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MCISME
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I looked for the EGR valve and have great knowledge of cars and engines and couldnt seem to find it. I looked in my Haynes repair manual and where it shows the egr valve for a 3.3L engine there is none. Hynes Manual shows it bolting to the top of the air intake and there is a bolt hole and a electrical hook up, but no valve. I swear i thought i saw it on that car before but i looked as best i could and couldnnt see it.

There is no vacume lines unhooked as if it were to go to the egr valve. I will have a mechanic friend show me where it is ifmy car has one.

The repair manual says some of the problems of a bad egr valve is rough idling and car stalling and stuff, it was making me think it was the egr valve until i couldnt find it.
Jun 7, 2009 at 7:02 AM
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GALLAWAYCG
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these vehicals do not have a egr valve unless its from california
Jun 4, 2012 at 10:57 PM