my car idles up every now then I can turn engine off and most of the time when i restart it will be ok I have found bad vac hoses and replaced them thought that fixed it but some times it still does it Iam thinking could the egr valve be the problem from what ive been reading Ive cleaned the thottle body it seems to help for a while help triump68 thanks
problem with engine idle on 1996 Cadillac Eldorado
by triump 68 in Williamston, SC on July 20, 2011
ANSWER by charles73michna , March 27, 2012
1st, clean the tubes inside the TB. carbon builds up in those tubes causing the TPS, EGR, MAP to all read bad and sparatic idle. the parts i just mentioned are fairly cheap and depending on mileage, might not be bad idea to replace anyway. if that doesn't work, i know of a crankshaft position sensor that could be bad, last resort though. i changed the throttle position sensor and MAP along with cleaning the heck out of the TB and egr tubes inside. use TB cleaner or electrical cleaner, just go easy with it. it evaporates quickly making good choice. I also would check codes, just keep in mind that one sensor can throw off computer to show multiple errors. after making 1 repair, disconnect negative battery cable for 10 minutes, this wipes out codes from computer and memory, drive for at least 10 min, rural and hwy speeds if possible. try to run all out if you can for a 1/4 or 1/2 mile, it will help. just a suggestion, if you run your gas down to 1/4 tank or less more regularly then you wish I would add evaporative cleaner for gas tanks, autoparts store will know which one. it will help rid tank of water that collects on bottom from bad gas and condensation.