tjenkins Posted December 5, 2003 Share Posted December 5, 2003 For the past 4-6 months or so, car seems to idle rough, more or less, upon startup and when warmed up. New plugs, wires, a tank of hi-test gas doesn't affect it.No error codes either.Any ideas?--Tom Link to comment Share on other sites More sharing options...
ronvb Posted December 5, 2003 Share Posted December 5, 2003 No cost items first--check vacuum lines for breaks or disconnect.ronvb Link to comment Share on other sites More sharing options...
Shelby Posted December 5, 2003 Share Posted December 5, 2003 Check the fuel pressure.I think it is the fuel pump. or filter if you are lucky. Use a AC Delco pump it is worst the extra bucks. Link to comment Share on other sites More sharing options...
padgett Posted December 5, 2003 Share Posted December 5, 2003 If it runs good otherwise, the first thing I do for an erratic idle is to clean the IAC. Link to comment Share on other sites More sharing options...
Roadster90 Posted December 5, 2003 Share Posted December 5, 2003 Hi Tom,,,Try cleaning your IAC that you will find mounted around the throttle body. Clean the throttle body and MAF also as long as you are there. No real cost involved except spray carb cleaner, and it just might cure your problem. Put a rag under the IAC when removing the two mounting screws...they are stainless steel and are not magnetic if you unintentionally drop one/them.Good luck,Nic Link to comment Share on other sites More sharing options...
tjenkins Posted December 5, 2003 Author Share Posted December 5, 2003 Had them cleaned several months ago - same problem. The idle isn't non-steady - just rough.--Tom Link to comment Share on other sites More sharing options...
Guest wally888 Posted December 6, 2003 Share Posted December 6, 2003 For a period of time before my A/C clutch failed (frooze in on) I had a rough idle. Almost caught on fire. Must have also had a bad compressor causing a lot of drag on engine at idle? Link to comment Share on other sites More sharing options...
Roadster90 Posted December 6, 2003 Share Posted December 6, 2003 Tom, may sound silly, but check for loose spark plug wire ends at the plugs. Also open hood at night and look to see if any plug wires are shorting out....arching....if so reroute the wiring. Link to comment Share on other sites More sharing options...
padgett Posted December 6, 2003 Share Posted December 6, 2003 Years ago I had a Champion plug that would not fire below 2500 rpm but was fine above. Made for interesting sounds through an open exhaust. Am assuming it runs fine/gives good MPG off idle ? Link to comment Share on other sites More sharing options...
tjenkins Posted December 6, 2003 Author Share Posted December 6, 2003 Yes, runs fine - anything above idle seems to be very smooth. Changed the plugs 6 months ago - Delco at factory setting.Btw, the idle is rough, and I can feel it (sometimes a small vibration, sometimes really noticable vibration) in the brake pedal when depressed at a stop sign etc.--Tom Link to comment Share on other sites More sharing options...
Guest wally888 Posted December 6, 2003 Share Posted December 6, 2003 Is very easy to end up w/ a bad wire connection at one of the rear plugs especially if metal insulators are installed. Did you raise hood in dark to look for misfire? Link to comment Share on other sites More sharing options...
padgett Posted December 6, 2003 Share Posted December 6, 2003 "Delco at factory setting" - if you mean R44LTS gapped .060, that may be the problem, unless the secondary ignition is absolutely tip-top, the Magnavox system has trouble firing .060. I use RapidFire #3s gapped at .040 in mine. Now that I have a Delco ignition am tempted to try the #14s (.060) and see if there is a difference.If the problem manifests mostly at idle, I'd pull plug wires at the coil with well insulated pliers and see if any make no difference. Link to comment Share on other sites More sharing options...
Guest Dolores Posted December 7, 2003 Share Posted December 7, 2003 I don't know if this will help or not but here it is. My mechanic always felt my car just didn't run the way it should (rough idle). Just recently received a service engine code which indicated the camshaft sensor was bad. Had a 100,000 mile tuneup, new alternator, new timing chain, new camshaft sensor and crankshaft sensor, new oil pan and gasket. Runs like a dream. I know you may say wow what did she not replace. Well, I trust my mechanic totally for all that work he only charged me $435 in labor and I know that's cheap. Link to comment Share on other sites More sharing options...
Taylor Weaver Posted December 10, 2003 Share Posted December 10, 2003 I had the same proble, a little while ago. I took it into the mechanic and got all the spark plugs and wires changed. when i drove it out of the place, it was much, much worse, so I took it back in. It ended up that the ignition coils were bad, so they had to be replaced. In the end, it was alittle expensive, maybe 150 or so, i don't quite remember, but it was well worth it. Link to comment Share on other sites More sharing options...
knjake Posted December 10, 2003 Share Posted December 10, 2003 Drive on over to Autozone and they will check out your ignt. coils and mod. at no charge, they don't require you to purchase any part found to be faulty. Link to comment Share on other sites More sharing options...
padgett Posted December 10, 2003 Share Posted December 10, 2003 If it feels good at 47-49 mph locked up, the secondary ignition is probably good. What is your idle rpm doing ? 3800 will shake under 600 rpm. Link to comment Share on other sites More sharing options...
Guest Posted December 10, 2003 Share Posted December 10, 2003 My 1988 Reatta has over 250,000 miles on it, and as the original owner, I have had an assortment of rough idle situations, caused by different things. The most elusive one was caused by a small quarter sized PLASTIC DISC, sandwiched in among the "assembly" that controls the idle. It was "frozen" in place and caused all the trouble, although at a quick glance it appeared fine. The mechanic brought the whole assembly out to show me and the service rep, but I couldn't tell you exactly what it was, but it was easily held in two hands. Once that part was replaced, the pesky idle was fine. Link to comment Share on other sites More sharing options...
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