Posted By: Moeggenpar
extremely rough idle.. - 06/08/14 09:44 PM
My 94' 2.5 Acclaim suddenly developed a rough idle where it barely keeps running. It sounds like it's firing on three cylinders.I could not find any vacuum leaks but replaced the PVC valve due to dry rot and installed new plugs,wires,cap and rotor because it was needed.Could a bad map sensor or EGR sensor cause this problem? I got the car from my mom and it only has 56K miles.Thanks for any info
Posted By: zrxkawboy
Re: extremely rough idle.. - 06/08/14 11:59 PM
Wish I could remember more, but its been years since I messed with one of those. The EGR valve and MAP sensor mentioned are good possibilities. Other things that come to mind are coolant temp sensor and pick-up coil. Also, have you tested the fuel pressure?
Posted By: moretoys
Re: extremely rough idle.. - 06/09/14 12:53 AM
a stuck open egr valve can cause a rough idle,( creates an interenal vacuum leak) but The map sensor will show low vacuum and the vehicle will be running rich. map sensor reading wrong will usually cause hesitation on acceleration or rich running due to low vacuum reading.(both usually set a map code) need a scan tool and read what the sensors are doing, otherwise just wasting money throwing parts at it. do a compression test, see if there is a low cylinder, Positive you don't have a crossed plug wire? bad head gasket?? coolant full??, compression test would show this, how did the spark plugs look? timing set to spec?, bad engine mounts will cause these things to shake / vibrate also. Does it run bad or just shake?
Posted By: Challenger 1
Re: extremely rough idle.. - 06/09/14 04:26 PM
web page web page I got my EGR parts from Car Quest at about 35 for a EGR valve for a 5.7 hemi while the dealer wanted 65.+ bucks for it. It's been in service now for 47K miles and no problems. So I'd say the one from the aftermarket are good enough?
Not saying I think it's the egr valve on your car, I have no idea really. Ours threw a code and I posted it here and was told it meant EGR which turned out to be right.
Did you check for codes if your car has them in 94?