Some idle annoyances May 04, 2005, 05:27:47 AM My car is idling really roughly for seemingly no reason. Runs fine other than idle. It's more of a minor annoyance than an actual problem at this point, but I'm just fishing for ideas. All the ignition parts are new less than a year ago (cap, rotor, wires, plugs) Here's my list of possible culprits:Fuel pumpFuel filterI can fix almost anything, diagnosing is where I have the problem. I checked for vacuum leaks and couldn't really find anything. Maybe I just got a bad tank of gas? I dunno, feel free to add to the list. It also might be a good idea to put up an FAQ sticky on things to check when your car's running rough or not at all. I see quite a few generic threads similar to this one. Quote Selected
Re: Some idle annoyances Reply #1 – May 04, 2005, 08:21:45 AM EGR valve stuck open just a bit? Quote Selected
Re: Some idle annoyances Reply #2 – May 04, 2005, 08:52:18 AM Quote from: MasterBlasterEGR valve stuck open just a bit?A lot more likely than the F/P or filter. They generally cause problems at speed.... Quote Selected
Re: Some idle annoyances Reply #3 – May 04, 2005, 11:02:28 AM Quote from: amoosetI can fix almost anything, diagnosing is where I have the problem. dont feel bad,, this is a pretty wide open problem.id just tinker over the next few days with vac lines and other general checks to see which one is not normal. therangerstaion.com has an emissions link which shows vac guage illustrations with relation to possible problems. that might interest you also.Im not sure how far you've gotten into your cfi work but its probably a good idea to doublecheck and see if the base of the cfi isnt a little warped. Mine was and i put it on a belt sander to make it flat again. I had no luck picking up on this vac leak with carb cleaner because it was so minor.im looking at my 87 emission/engine shop manual now and you really dont wanna know the list of probable causes for "Rough Idle"scott Quote Selected
Re: Some idle annoyances Reply #4 – May 04, 2005, 12:02:17 PM I have a thread here in this same section a little further down the page. Theres a lot of great advice in it that might help you out too. I've yet to get to the bottom of my idle problem, but I'm still testing different things and haven't had a chance to check all of the possibilities. Best of luck! Quote Selected
Re: Some idle annoyances Reply #5 – May 04, 2005, 03:14:29 PM Quote from: Metal MattI have a thread here in this same section a little further down the page. Theres a lot of great advice in it that might help you out too. I've yet to get to the bottom of my idle problem, but I'm still testing different things and haven't had a chance to check all of the possibilities. Best of luck!I already read through that, but a lot doesn't really apply to my situation. I realize that I didn't specify, but I have a 3.8 with CFI. Quote Selected
Re: Some idle annoyances Reply #7 – May 06, 2005, 05:29:52 PM I remember reading a Service Bulletin awhile ago that applied to cars with no A/C having idle problems. It had something to do with with the ACC line to the EEC. This line tells the EEC the A/C clutch is engaged so the EEC can speedup the idle.This line out in the engine bay not hooked to anything was picking spurious pulses and confusing the EEC. The cure was to cut and tape up the ACC line near the EEC plug.I know a lot of people on the board have removed their A/C, so it may be something to keep in the back of your mind even though it seems far fetched. Quote Selected
Re: Some idle annoyances Reply #8 – May 06, 2005, 08:02:30 PM ok,, ill ask,,,,,,,,of the list of things to do that i sent you,,, what have you done to your engine.vac lines (all)cfifprfpsmogpvccfi gold fitting on rear for 84 and updoes the idle control motor retract after warm up?does the little preheat dohicky on the driver side of the intake ***CLOSE*** after warm up? (blk/or rubber vac line)ect ectjust curious so im not thinking of stupid things like plug or a cfi gasket or the Idle control motor ect. Quote Selected
Re: Some idle annoyances Reply #9 – May 13, 2005, 10:19:56 PM Upon inspection, I discovered that a vacuum line had come off. I reconnected that, with little improvement. Then I noticed that the fuel injector had popped off somehow (eh?) and was leaking out the top. I thought maybe the retaining bolt on the underside had come off, but the other injector was seated just fine, plenty tight. Just one side is loose. I just zip tied it back into place (now it looks about like jcassity's ghetto mounting system ) and she runs like a champ. Now I just need to fix my horrendous exhaust leak. Quote Selected