Announcement

Collapse
No announcement yet.

88 Town Car random misfire

Collapse
X
Collapse
 
  • Page of 2
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
    #1

    88 Town Car random misfire

    Got a new daily driver 1988 Town Car, it had been sitting for a few years but was running when I got it, just not well. I did some work to it but still seem to have a random misfire. It's easiest to feel when I put the car in gear and give it a bit of throttle, miss is not consistent, it's random, a miss here or there and then smooth for a while then a another miss or three. Once I'm driving at speed or even just normally I hardly notice it, if it even misses at all. It runs terrible when cold missing badly under load and it takes a few tries to start it when it's cold. Starts right up when it's warm and most of the noticeable missing goes away.

    I replaced spark plugs, cap and rotor, bench tested and cleaned the injectors, replaced the fuel filter and checked for vacuum leaks: fixed some broken plastic lines for the smog pump/egr control and a couple hoses under the intake. Currently it idles at about 19" of vacuum. I pulled codes and there were none, I checked it a couple times to make sure.

    Any thoughts on what to check next? I thought I knew these motors pretty well but it's been a decade since I've had stock one to work on!
    Last edited by drhill; 05-01-2024, 05:50 PM.
    1984 Mercury Colony Park Wagon - gone to the darkside. 5.3 LS Turbo Swap with 4L80E. 6.62@106 in the 1/8 mile (low 10's in the 1/4), full weight, AC, no compromises! Rocky Mountain Race Week 2020 and Race Week 2.0 2020
    Tags: None
    #2
    What sort of shape are the plug wires in? Are they routed properly? Coil terminal isn't a crusty mess is it?

    Maybe check it for codes, and measure the voltage or resistance on the air and coolant temp sensors to make sure one hasn't gone stupid.

    http://www.grandmarq.net/oldfuelinjection/page10.html



    Last edited by gadget73; 05-01-2024, 05:59 PM.
    86 Lincoln Town Car (Galactica).
    5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

    91 Lincoln Mark VII LSC grandpa spec white and cranberry

    1984 Lincoln Continental TurboDiesel - rolls coal

    Originally posted by phayzer5
    I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

    Comment

      #3
      Originally posted by gadget73 View Post
      What sort of shape are the plug wires in? Are they routed properly? Coil terminal isn't a crusty mess is it?

      Maybe check it for codes, and measure the voltage or resistance on the air and coolant temp sensors to make sure one hasn't gone stupid.

      http://www.grandmarq.net/oldfuelinjection/page10.html


      wires look good, routing is not the best but I checked them all for possible ground paths etc, I will do that again at night in the dark. cleaned the coil terminal - no change. No codes at all, I did check that. I will also look at the Temp sensors and test them thx! Where is air charge temp sensor - I don't remember where that one is. i went back out to test it again, seemed a bit worse with some heat soak if that means anything? still cleans up and runs good with higher rpm and load
      Last edited by drhill; 05-01-2024, 06:16 PM.
      1984 Mercury Colony Park Wagon - gone to the darkside. 5.3 LS Turbo Swap with 4L80E. 6.62@106 in the 1/8 mile (low 10's in the 1/4), full weight, AC, no compromises! Rocky Mountain Race Week 2020 and Race Week 2.0 2020

      Comment

        #4
        ACT is in the lower intake just behind #5 injector

        by no codes at all do you mean no codes at all, or no faults and you got an 11 ?
        86 Lincoln Town Car (Galactica).
        5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

        91 Lincoln Mark VII LSC grandpa spec white and cranberry

        1984 Lincoln Continental TurboDiesel - rolls coal

        Originally posted by phayzer5
        I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

        Comment

          #5
          Originally posted by gadget73 View Post
          ACT is in the lower intake just behind #5 injector

          by no codes at all do you mean no codes at all, or no faults and you got an 11 ?
          Ah yes, I remember now. No faults, I got 11 for KOEO and KOER
          1984 Mercury Colony Park Wagon - gone to the darkside. 5.3 LS Turbo Swap with 4L80E. 6.62@106 in the 1/8 mile (low 10's in the 1/4), full weight, AC, no compromises! Rocky Mountain Race Week 2020 and Race Week 2.0 2020

          Comment

            #6
            https://youtu.be/IFlQxkp9iac


            No sparks visible tonight from the plug wires, I also checked the fuel pressure and it appears to be normal a little over 30 at idle with FPR connected and about 42 or 43 psi with it disconnected and plugged. see attached video for what the miss feels like in gear
            Last edited by drhill; 05-02-2024, 01:04 AM.
            1984 Mercury Colony Park Wagon - gone to the darkside. 5.3 LS Turbo Swap with 4L80E. 6.62@106 in the 1/8 mile (low 10's in the 1/4), full weight, AC, no compromises! Rocky Mountain Race Week 2020 and Race Week 2.0 2020

            Comment

              #7
              Double check that all the spark wires are fully seated. I know I've had issues when changing out wires that the boots sometimes slip off and need to be reseated and will stay put then.

              Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
              rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
              Originally posted by gadget73
              ... and it should all work like magic and unicorns and stuff.
              Originally posted by dmccaig
              Overhead, some poor bastards are flying in airplanes.
              • Likes 1

              Comment

                #8
                random thought, pull the green vac line off the EGR and see if anything changes. I had issues with a sticky EGR reg once causing the valve to open full just off-idle and it did odd things.
                86 Lincoln Town Car (Galactica).
                5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                91 Lincoln Mark VII LSC grandpa spec white and cranberry

                1984 Lincoln Continental TurboDiesel - rolls coal

                Originally posted by phayzer5
                I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                Comment

                  #9
                  Originally posted by gadget73 View Post
                  random thought, pull the green vac line off the EGR and see if anything changes. I had issues with a sticky EGR reg once causing the valve to open full just off-idle and it did odd things.
                  Damn, the guru strikes again! I installed new plug wires and routed them as best as I could and it helped a bit. I unplugged the green vacuum line from the egr and problem is solved. So given that worked, what needs to be fixed/replaced since the green egr line fixed my issue?

                  BTW, you and Sly have been around forever on this site, I bought my first panther in like 2011 and you guys were well established way back then, how long have you guys been on here? Nevermind - I forgot I can see your join dates!
                  Last edited by drhill; 05-03-2024, 02:55 PM.
                  1984 Mercury Colony Park Wagon - gone to the darkside. 5.3 LS Turbo Swap with 4L80E. 6.62@106 in the 1/8 mile (low 10's in the 1/4), full weight, AC, no compromises! Rocky Mountain Race Week 2020 and Race Week 2.0 2020

                  Comment

                    #10
                    Originally posted by drhill View Post

                    Damn, the guru strikes again! I installed new plug wires and routed them as best as I could and it helped a bit. I unplugged the green vacuum line from the egr and problem is solved. So given that worked, what needs to be fixed/replaced since the green egr line fixed my issue?

                    BTW, you and Sly have been around forever on this site, I bought my first panther in like 2011 and you guys were well established way back then, how long have you guys been on here?
                    Hah, I'm going to try investigating EGR as an issue with the 5.8 in my truck as well.

                    I remember lurking around this site before I was a member and noticing sly and gadget73 were top posters who gave solid advice & tips. Then I remember that giddy feeling the first time either of them replied to my post or comment: "Yes! The gurus have spoken!" Very similar to, "Oooh! The Claw! It moved!"
                    1985 LTD Crown Victoria - SOLD
                    1988 Town Car Signature - Current Party Barge

                    Comment

                      #11
                      Its probably something goofy with the EVR. The solenoid on the fender that the other end of that green line goes to. Canned answer is a new one, but I fixed mine by taking the cap off, cleaning all the dust out from the disintegrated foam filter that used to live in there, and shooting some WD40 in each of the ports to flush it out. Worth a shot, otherwise it probably just needs to be replaced. Mine wasn't regulating, it was just going full open just off-idle which is what it sounds like yours is doing.
                      86 Lincoln Town Car (Galactica).
                      5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                      91 Lincoln Mark VII LSC grandpa spec white and cranberry

                      1984 Lincoln Continental TurboDiesel - rolls coal

                      Originally posted by phayzer5
                      I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                      Comment

                        #12
                        yeah, that makes sense. I'll clean it out first before getting a new one. Gotta get it through a smog test next week. Weird that it didn't throw a fault code
                        Last edited by drhill; 05-03-2024, 06:11 PM.
                        1984 Mercury Colony Park Wagon - gone to the darkside. 5.3 LS Turbo Swap with 4L80E. 6.62@106 in the 1/8 mile (low 10's in the 1/4), full weight, AC, no compromises! Rocky Mountain Race Week 2020 and Race Week 2.0 2020

                        Comment

                          #13
                          it won't for this specific problem. Its not quite smart enough to verify that if it commanded say 20% open that the position sensor actually opened 20%. It just knows that it opened when told to and shut when told to and the position sensor was somewhere in the range that it was happy with.
                          86 Lincoln Town Car (Galactica).
                          5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                          91 Lincoln Mark VII LSC grandpa spec white and cranberry

                          1984 Lincoln Continental TurboDiesel - rolls coal

                          Originally posted by phayzer5
                          I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                          Comment

                            #14
                            So - bought a new EVR and installed it, car still misfires with it hooked up. not as badly as the original EVR but still missing. With it disconnected from EGR, runs perfectly no issues. Any thoughts?
                            1984 Mercury Colony Park Wagon - gone to the darkside. 5.3 LS Turbo Swap with 4L80E. 6.62@106 in the 1/8 mile (low 10's in the 1/4), full weight, AC, no compromises! Rocky Mountain Race Week 2020 and Race Week 2.0 2020

                            Comment

                              #15
                              hm, sounds like the evr is passing vacuum to the egr when it shouldn't be.

                              the other thing I found that causes that is no VSS input for some completely baffling reason but that will set a code. If the cruise works its definitely got good VSS.
                              86 Lincoln Town Car (Galactica).
                              5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

                              91 Lincoln Mark VII LSC grandpa spec white and cranberry

                              1984 Lincoln Continental TurboDiesel - rolls coal

                              Originally posted by phayzer5
                              I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

                              Comment

                              Previous 1 2 template Next
                              Working...
                              X