Announcement

Collapse
No announcement yet.

Rough Idle at Cold Start

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Rough Idle at Cold Start

    Yes, I know I could check the old posts because this is probably a frequently asked question, but I prefer to communicate with people. Or else I wouldn't be here. Right.

    So anyways, the 1993 TC seen in sig pic is idling really rough and irraticly when I start her up first thing in the morning. Ambient temperature has little effect, but the motor being cold is the problem. Any tips would be appreciated. I recently cleaned out the egr passages and it ran really great for a couple weeks, but now this. Do the fuel injected cars have the idle air control valve, and could it be that?
    Back in the saddle again!

    2004 Crown Victoria Police Interceptor in Unimaginative Bureaucratic Brown
    Bone stock... for now.

    #2
    The idle air control problem seems to effect all panther platform cars .

    I would start there if it were my car.

    But Im not gonna SAY thats what it is cuz I have never worked on a TC.

    Comment


      #3
      As far as I know, there's no significant difference under the hood of a TC and a CV/GM. The TC has some extra equiptment because of the air ride, but mine is turned off right now anyways. I hear alot of reference to the IAC valve when people mention idle problems, so it was a shot in the dark.
      So if it is the IAC, is that an easy thing for an amateur mechanic to service? And would servicing it mean doing a cleaning or a replacement?
      Back in the saddle again!

      2004 Crown Victoria Police Interceptor in Unimaginative Bureaucratic Brown
      Bone stock... for now.

      Comment


        #4
        How old are your spark plug wires?

        Moisture (condensation) can form overnight and cause cross-induction resulting in a random misfire until the engine bay warms up and the moisture evaporates.
        1987 LTD CROWN VICTORIA, 5.0 EFI, MAGNAFLOW DUAL EXH, RED LANDAU
        FRESH AOD, 3.27 OPEN DIFF, 57K MILES, B&M SHIFT KIT AND R134A A/C


        Comment


          #5
          I put them in during summer of 2006. I'd venture to guess they have anywhere between 13-18,000 miles on them. And they were not top-of-the-line to start with. I had wondered about them when I had weak performance conditions previously, but then learned of the common egr issues and started there. As I mentioned, things did improve alot, but maybe the plug wires have croaked now. Lets say these plug wires have 15,000 miles on them. What is the likelyhood they need replacing?
          Back in the saddle again!

          2004 Crown Victoria Police Interceptor in Unimaginative Bureaucratic Brown
          Bone stock... for now.

          Comment


            #6
            Best way I know is to let your car warm warm up and smooth out, then take a spray bottle and spray water on the plug wires, watch for arcing and see if the motor starts missing and running rough.
            1987 LTD CROWN VICTORIA, 5.0 EFI, MAGNAFLOW DUAL EXH, RED LANDAU
            FRESH AOD, 3.27 OPEN DIFF, 57K MILES, B&M SHIFT KIT AND R134A A/C


            Comment


              #7
              Originally posted by 87vicFIVEO View Post
              Best way I know is to let your car warm warm up and smooth out, then take a spray bottle and spray water on the plug wires, watch for arcing and see if the motor starts missing and running rough.
              This isn't one of those things where I take your advice and try it, and I wake up days later in a hospital and discover that I've been a contestant on America's Funniest Home Videos, is it? I always heard water and electricity are a no-no.

              In all seriousness, what you are describing makes sense. It would be easier to see the electricity arcing in the dark, so I think I'll do it tomorrow after sundown. Thanks!
              Back in the saddle again!

              2004 Crown Victoria Police Interceptor in Unimaginative Bureaucratic Brown
              Bone stock... for now.

              Comment


                #8
                does the idle when starting it up do this?

                start up, idle is high, drops low feels rough, raises high smooths out, drops lower again feels again rough, then smooths out?

                if it does something like that most likley its a IAC

                1999 P74 HPP 3.27 RAR

                Comment


                  #9
                  Wow im getting alot of mileage from this post

                  Originally posted by 97cv View Post
                  .


                  This is your IAC ( Idle Air Control valve ). This picture is EXACTLY how its gonna look when you find it behind your TB.



                  Its going to be held on by 2 Phillips bolts. I suggest trying to WARM not HEAT it when you try to remove it. Its easy cheesey 1,2,3-sey.

                  Lastly from what I have read. There isnt really an effective way to clean it-Good news is there are CHEAP, And NO Junkyard finds wont have the same life span as a new one.

                  Comment


                    #10
                    Yeah Tack, that sounds about right. Not always in that order, but that's basicly it. Then when it's warm, no problem at all.

                    97cv, thanks for the pic and the location information. Looks like I've got another project!

                    And I'm gonna check out the plug wire thing too, probably do it first, the IAC next weekend after I get paid again. Thanks for all the help guys!
                    Back in the saddle again!

                    2004 Crown Victoria Police Interceptor in Unimaginative Bureaucratic Brown
                    Bone stock... for now.

                    Comment


                      #11
                      yea it tends to do it when warm but dont jump up and down as much as when cold.

                      autozone is 53 bucks for an IAC.

                      1999 P74 HPP 3.27 RAR

                      Comment


                        #12
                        Check your EGR passages again chuck.. My '92 burned oil like a stove and idled like crap almost all the time

                        I relaced the IAC and IAT...But it still idled like crap
                        Last edited by Grandmarchris; 02-20-2008, 03:13 PM.
                        R.I.P Linsey Nelson

                        '04 M75-"Chocolate Rain" - mid 13 beast
                        Originally posted by MeanVic84
                        Chocolate Rain. Some stay dry and others feel the pain.

                        Comment


                          #13
                          Check your Water Temp Sensor. Mine would cause idleing and low speed driving issues. It would also happen at different temps as it warmed up. Cold no prob....about 130 degrees crapy idle....ok at 150 to 180 then capy idle again.. 195 ok. Eventually it began occuring at a broader range of temps.
                          Scars are tatoos of the fearless

                          Comment


                            #14
                            could tap it with a screwdriver handle while its doing it to see if it smoothes out.
                            Chris - A 20th Century Man \m/ ^.^ \m/

                            Comment


                              #15
                              Soon as my cold break up I'll have to check out some of these suggestions. P71Towny, when you say to "tap it with a screwdriver" do mean the IAC?
                              Back in the saddle again!

                              2004 Crown Victoria Police Interceptor in Unimaginative Bureaucratic Brown
                              Bone stock... for now.

                              Comment

                              Working...
                              X