Car runs rough in open loop
jd87sep
03-01-2005, 01:50 AM
I have a 92 rs, 305 TBI. Recently I found out that my cats were bad, and were getting so hot they were burning my carpet. I replaced them, and they aren't getting too hott, but the floorboard gets pretty warm when the engine is cold. Any suggestions as to why it would run rough in open-loop? I figured since the cats were getting so hot that it was running rich, because all that gas was just heating up in the cats.
dolluper
03-01-2005, 02:20 PM
Your car in open-loop is basicaly running off your CTS coolant temp sensor as temp rises your setings change [fuel airmixture idle speed +++] these are predetermined at factory in computer so an out of value CTS can affect your proformance The TPS throttle postion sensor is also used untill warmed up and in CLOSED LOOP
DaMoNe6969
03-02-2005, 05:41 PM
Does it only run rough while warming up??
jd87sep
03-02-2005, 09:33 PM
yes, it only runs rough in open loop, when warmed up, it runs fine. The fan is rigged to always be on, which hints to me that the CTS that dolluper was talking about is bad, and someone just decided to start hackin wires away.
dolluper
03-04-2005, 09:37 AM
One thing you have to consider in open -loop the computer is preset values and the condition of plugs wires [cap rotor] base timing have a greatter affect in the running of the engine even fuel pump condition
jd87sep
03-07-2005, 11:57 PM
update. Scanned it, and got a code 32 and 54. EGR and Fuel pump errors. EGR is getting taken off and checked for vacuum...Hopefully it's just some carbon build-up. I'll update tomorrow. By the way, plugs, wires, distributor cap, rotor...all brand new.
jd87sep
03-10-2005, 11:12 PM
let it warm up, and I got vacuum only when accelerating, but when i held it at a steady speed, there was no suction at all. Is this how it's supposed to operate?
dolluper
03-11-2005, 08:16 PM
Feel underneath egr at approx 1500rpm it should move the valve
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