Rough Idle and Surging
#1
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Hey all,
2000 SS, MN6
Well here's the story, just changed the fuel filter, new SLP air lid (removed my Direct Flow, it was cracked), new air filter. I took off my MAF ends and just looked at them to make sure they were not dirty and the screen was not clogged. Oil change with Moble 1 10W30 and Moble 1 Filter (M107), new PCV valve and new plugs, NGK TR55 IX (Iridum) gapped checked out of the box at 0.57-0.58 left them they way they were. Also did a Seafoam treatment, sucked half the bottle slowly throught the PCV hose, let sit for about an hour and then ran the **** out of it. Not much smoke at all. I did this before I did the oil change and plugs. Oh yeah checked my EGR and the O ring that I replace 4 years ago was cracked replaced that with another o ring.
Now all of a sudden the idle is choppy (feels like a a mis or something) and there is surging when I'm starting from a stop only in first gear, and sometimes when I grab second. But the weird thing is that once I'm in gear and above 2000 rpms the engine is smooth, now burps hicups or surging. Cruising and 1/2 to 3/4 throttle is also fine. Sometimes the surging upon acceleration is not that bad and sometime not at all, sometimes it's horrible.
When I was doing the plugs, on the drivers side I had to remove the 2 wire plug/sensor off the head right near the front of the head, and I did start the car with that unplugged (forgot to plug it in), what is this? Temp sending unit? Also on the passenger side I had to remove the AIR tube of the manifold to get to plugs #2, 4, 6. I did not replace the aluminum gasket. Also wire #8 gave me a hell of a time getting off I was under there for at least a half hour wrestling with this. Plug came out easy though.
I checked the PCV system, where i left the hard line PCV open to the air without the PCV valve installed and capped the Throttle body and it still had a crappy idle and surging. I re-seated all the plug wires except #8 (did not have time to put car up on jacks.
And last thing, this is the first time that i actually drove the car up on my Rhino Ramps, I usally jack up and put the car on the ramps. Well I can tell you that I know I burnt the clutch a little because when i got it up there, finally, I smelt buring clutch.
I already ordered new wires and replacement gaskets for the AIR tube to manifiold. I will check #8 wire today. But what else can this be. Please help
Obi Wan your my only hope.
Thanks
Nick F
2000 SS, MN6
Well here's the story, just changed the fuel filter, new SLP air lid (removed my Direct Flow, it was cracked), new air filter. I took off my MAF ends and just looked at them to make sure they were not dirty and the screen was not clogged. Oil change with Moble 1 10W30 and Moble 1 Filter (M107), new PCV valve and new plugs, NGK TR55 IX (Iridum) gapped checked out of the box at 0.57-0.58 left them they way they were. Also did a Seafoam treatment, sucked half the bottle slowly throught the PCV hose, let sit for about an hour and then ran the **** out of it. Not much smoke at all. I did this before I did the oil change and plugs. Oh yeah checked my EGR and the O ring that I replace 4 years ago was cracked replaced that with another o ring.
Now all of a sudden the idle is choppy (feels like a a mis or something) and there is surging when I'm starting from a stop only in first gear, and sometimes when I grab second. But the weird thing is that once I'm in gear and above 2000 rpms the engine is smooth, now burps hicups or surging. Cruising and 1/2 to 3/4 throttle is also fine. Sometimes the surging upon acceleration is not that bad and sometime not at all, sometimes it's horrible.
When I was doing the plugs, on the drivers side I had to remove the 2 wire plug/sensor off the head right near the front of the head, and I did start the car with that unplugged (forgot to plug it in), what is this? Temp sending unit? Also on the passenger side I had to remove the AIR tube of the manifold to get to plugs #2, 4, 6. I did not replace the aluminum gasket. Also wire #8 gave me a hell of a time getting off I was under there for at least a half hour wrestling with this. Plug came out easy though.
I checked the PCV system, where i left the hard line PCV open to the air without the PCV valve installed and capped the Throttle body and it still had a crappy idle and surging. I re-seated all the plug wires except #8 (did not have time to put car up on jacks.
And last thing, this is the first time that i actually drove the car up on my Rhino Ramps, I usally jack up and put the car on the ramps. Well I can tell you that I know I burnt the clutch a little because when i got it up there, finally, I smelt buring clutch.
I already ordered new wires and replacement gaskets for the AIR tube to manifiold. I will check #8 wire today. But what else can this be. Please help
Obi Wan your my only hope.
Thanks
Nick F
#2
TECH Addict
iTrader: (77)
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i had a very similar problem in my 98 T/A. run some techron through it. let your take get nearly empty and then dump a bottle of techron concentrate into it, then fill it up with about 8 gallons of "quality" gas. it could be your fuel injectors. for me though it ended up being my knock sensor that went bad. pull a few of your easier plugs to get out and see if they are carbon fouled. i had just changed mine about 1,000 miles earlier and they were black with carbon already, if that is your case you may have a bad knock sensor and it should throw a code here pretty soon.
#3
11 Second Club
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Originally Posted by nick f
Hey all,
Now all of a sudden the idle is choppy (feels like a a mis or something) and there is surging when I'm starting from a stop only in first gear, and sometimes when I grab second. But the weird thing is that once I'm in gear and above 2000 rpms the engine is smooth, now burps hicups or surging. Cruising and 1/2 to 3/4 throttle is also fine.
Now all of a sudden the idle is choppy (feels like a a mis or something) and there is surging when I'm starting from a stop only in first gear, and sometimes when I grab second. But the weird thing is that once I'm in gear and above 2000 rpms the engine is smooth, now burps hicups or surging. Cruising and 1/2 to 3/4 throttle is also fine.
this is a text book desciption of a dirty IAC (idle air controler) is it located under your throttle body, if it gets dirty/grimy/wet it does all of the above exactly as you have described, and guess whenn 99% of the time it happens to people is? right after they did 5-6 mods/tuneup things/ cleaned engine bay at once
![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
take it out, clean with isopropanol and replace, 99% sure that will cure your trouble, if not the second place i would look (since you did mess with it) is your MAF, clean it with isopropanol as well...
let us know how it turns out...
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#4
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So after asking this question, I have come to belive that my IAC may be dirty. I replaced my Lid and Filter and cleaned up the throttle body with a rag (oil residue) and I believe that my idle and surging problem is from a dirty IAC. How do clean this? Do I use plain old Gunk carb cleaner with the engine off or on? Do I need a special cleaaner other than a degreaser? IPA Alcohol? Should I remove the IAC and clean it and then clean out the passage in the throttle body with something? Please comment.
Thanks
Nick F
Thanks
Nick F
#7
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So i went a bought some throttle body cleaner form Gunk, says its safe of IAC and what not. Took out the IAC, didn't look that bad. Sprayed the IAC, took out the o-ring and sprayed the the hole where the IAC was. Stuck a rag in there and wiped all the oil out of there. Re-installed and now it's slightly better, but not back to normal. I still have the rough, miss at idle, and sometimes now I get the surging loss of power engaging first gear. Sometimes I will here a pop from the exhaust during the engagment of first gear.
This morning, also did a IAC reset, did nothing. Please Help
Thanks
Nick F.
This morning, also did a IAC reset, did nothing. Please Help
Thanks
Nick F.
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#8
11 Second Club
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did you try a pcm reset? (long shot but it can also help in some cases)
pull your battery cables and leave off for 30 mins, reconnect and drive around for 30-40 mins so the car can relearn itsself...
also did you clean your MAF too?
pull your battery cables and leave off for 30 mins, reconnect and drive around for 30-40 mins so the car can relearn itsself...
also did you clean your MAF too?
#11
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Check for a cracked vacuum hose as well. I always crack or break those things when I get my big mugs in there for awhile. All the other things mentioned as well esp the gas treatment. Fuel filters can be bad off the shelf. If nothing else works I'd replace it. They should give you another free if you take the newly installed one back.
#12
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Thanks all, it was a combination of some things, I believe. A dirty IAC which I cleaned with Throttle body cleaner. A damaged pulg wire on #8 and a cracked plug on #4.
Thanks
Nick F.
Thanks
Nick F.
#13
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Thanks all, it was a combination of some things, I believe. A dirty IAC which I cleaned with Throttle body cleaner. A damaged pulg wire on #8 and a cracked plug on #4.
Thanks
Nick F.
Thanks
Nick F.