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Idle goes up almost to 1k sometimes
Posted: Wed Mar 18, 2009 5:03 am
by ericem
Hey guys. I noticed after I flushed my coolant system and all. Only a warm start the engine will chug a bit, like between 750-1000rpms it will bounce up and down. Also when I stop after the engine is warmed up, it will sometimes idle at like 500, then sometimes will go up to 1000rpm's when I stop
Also noticed sometimes the fans like to stay on. Could this simply be the ecu coolant sensor? Any other ideas? Thanks!
Posted: Wed Mar 18, 2009 5:10 am
by thehookeup
ECT sensors love to be replaced. does your IAC have coolant lines going to it? did you replace your thermostat when you flushed it. really not much of this makes much sense, but its a place to start
Posted: Wed Mar 18, 2009 5:50 am
by ericem
Yup replaced a crap load of hoses, thermostat, water pump. All oem.
Posted: Wed Mar 18, 2009 6:22 am
by thehookeup
check to see how much vacuum you have at idle, and then get an idea of what rpm (500-1000) and what your vacuum reading is between those ranges. sounds like a bad IAC
Posted: Wed Mar 18, 2009 6:30 am
by ericem
Funny you say that. The dealer pulled up some records on the car, and the IAC was replaced a few years ago with a new one. Same with the fuel pump which is loud.
Posted: Wed Mar 18, 2009 6:46 am
by thehookeup
just cause they replaced it, doesnt mean it hasnt gone bad lol. I went through 4 IACs granted not all of them were new, but they all couldnt have had that problem. Id just check that vacuum reading tomorrow, and let us know what it was
Posted: Wed Mar 18, 2009 6:50 am
by ericem
If it matters. I poured seafoam down the IAC hose.
Posted: Wed Mar 18, 2009 7:34 am
by tahiti350
Both of my '90's do that same surge thing, most comman after running it long enough to get full warm, then going in a store or something. Up and down for about 10 seconds, then smooths out. I just assumed it was an "off" spot in the fuel/temp maps...
Posted: Thu Mar 19, 2009 1:37 am
by ericem
Got a temp sensor. Tomorrow its going in
Posted: Thu Mar 19, 2009 9:20 pm
by ericem
Still the same problem. It didn't go as high of RPM actually and when I start it warm the idle doesn't bounce up and down anymore. Still doesn't seem perfect. What could these coolant lines going to the IAC do? Is it really important. Forgot to check the vacuum. I think it started doing this after pouring seafoam down the IAC maybe.
Still hear the fans run for more then a few minutes when I stop as well. I am thinking it might just be normal behaviour. Not sure about the idle though.
Posted: Fri Mar 20, 2009 3:33 am
by ericem
Was out tonight. Did it the first few minutes. After a few more restarts it went away. Maybe the ECU was relearning? Car seems pretty good. Interesting how I get alot of turbo lag when I floor it though.
Posted: Sun Mar 22, 2009 5:22 am
by ericem
I FINALLY make a video and the whole time while making the video, the idle was perfect. Before I made the video kept going up to 1k rpms at idle wtf!!
http://www.youtube.com/watch?v=Gdm4RRdGGnk
anyway enjoy. I did not floor it, just power light and mild throttle.