PotM GrandMarq.NET - Panther Headquarters Forum Index PotM
GMN Chat Room GMN's STORE!! GMN's Gallery Please!!
Page 1 of 2 12 LastLast
Results 1 to 20 of 27

Thread: 84 Town Car - always high idle for about 10miles then everything normal

  1. #1
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default 84 Town Car - always high idle for about 10miles then everything normal

    Any ideas on this?
    Must have something to do with engine temp. Didnīt notice this weird behaviour during summer.

    Cold engine - startup - high idle for about 30 seconds then pulls off. So everything normal so far.
    After a few minutes fast idle catches up again and keeps on for about 10 miles. Then it backs off to normal again and everything stays this way.
    This is only with AC off!! Turn AC on and idle slows down and you feel the acc pedal coming back. Just like with speed control on/off.

    Very annoying, especially around Town for it pushes you up to 45 mph easily.

  2. #2
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    1,114

    Default

    Have you checked if it's the throttle kicker that's acting wrong? When the high idle kicks up again, unhook the vacuum line from the throttle kicker.
    You should also check if the high idle mechanism (choke) is binding up or so.

    I don't think either system works related to engine temp. After the summer you did mess with the idle speed.
    1985 Mercury Grand Marquis LS, "Maisa"
    2008 BMW 530d Touring, "Femma"

  3. #3
    GMN Regular DerekTheGreat's Avatar
    Join Date
    Sep 2014
    Location
    Warren, MI
    Posts
    6,643

    Default

    Yeah, check the choke pull-off mechanism, sounds like it needs readjusted. That and the vacuum dashpot on the driver's side are the only things which adjust idle from base.
    1985 LTD Crown Victoria - SOLD
    1988 Town Car Signature - Current Party Barge

  4. #4
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default

    I did not have the time to check yet, since I always needed to go places in time when I took the car.
    Choke pulloff diaphragm is new.

    Yes, I did readjust the throttle kicker by the end of summer, which cured my random stalling on deceleration and hard stops.


    Isnīt that throttle kicker and pulloff vacuum switched by a the green three-port vacuum temp switch on the back of the manifold? At least this 3-port vacuum switch also controls the heat riser valve vacuum and I noticed that during this hi-idle period the temp gauge rises to HOT which indicates that the heat riser flapper is closed when it shouldnīt.

  5. #5
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    1,114

    Default

    From my understanding, only the heat control valve (on exhaust) gets controlled by the temp switch (if it is that) and the heat valve solenoid (frontmost solenoid on valve cover)
    The throttle kicker is controlled by the electronically controlled "T KICK" solenoid on the valve cover. If I'm not mistaken, the only thing that should activate the throttle kicker is the AC coming on.

    First you should definitely make sure the exhaust heat control valve isn't closing for some reason. That could create all sorts of fun issues. Disconnect the vacuum source, probably at the green valve, since it has a metal vacuum line from the back of the intake to the exhaust heat valve. Not having vacuum should keep it open.
    1985 Mercury Grand Marquis LS, "Maisa"
    2008 BMW 530d Touring, "Femma"

  6. #6
    all the CFI are belong to me
    Join Date
    Feb 2014
    Location
    Windsor, ON, Canada
    Posts
    2,133

    Default

    As I recall there is a "engine temperature OR elapsed time, whichever comes first" bit of programming that the computer does to control this, as mentioned via one of the solenoids. I believe the "elapsed time" is 2 minutes.

    At the moment that's all I can contribute, but I distinctly remember that my 84 works properly and did something along those lines.

    Current driver: 85 Ranger
    Panthers, Parked: 83 GM 2dr POTM 10/2019 | 84 TC POTM 1/2017 & 4/2019 | 85 CS | 86 GM | 88 TC | 91 GM POTM 12/2017
    Not Panthers, Parked: Ranger trailer | 05 Focus | 04 Focus
    RIP: 97 CV | 83 TC
    Junkyards

  7. #7
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default

    Linkage is all free. I noticed the choke cam was on the first step after a 3 mile run and then shutdown.
    Could it be that the electric choke cap is set wrong hence causing this "hang on 1st step"? And only noticed now with the lower ambient temps?

    Found no directions on how to set it in none of the shop manuals (body, emissions, powertrain)

  8. #8
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    1,114

    Default

    It could be that the choke spring is set too far, or the spring is weak.

    I have no idea of a proper procedure, I just did by feel. The CFI doesn't need much throttle input when cold just to stay running. When I adjusted mine, it was about 10°C, and the engine wouldn't quite stay running while cold.
    With a cold engine, twist the choke cap just so the arm gets on the lowest step when throttle is opened a bit. The screw adjusts the RPM of high idle, mine is pretty much lowest it can go.

    When starting the car, one should stab the throttle to engage the high idle cam and then start the engine. As the choke spring warms up, it should get off the high idle cam when throttle is applied again (or just driving).

    https://workshop-manuals.com/ford/mu...dle/page_1265/
    There's the set procedure, but it doesn't say anything about setting the cap.
    1985 Mercury Grand Marquis LS, "Maisa"
    2008 BMW 530d Touring, "Femma"

  9. #9
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default

    Aha! That would explain why I donīt need no throttle at all to start the car. The choke spring is pulling as soon as ign is on. I bet the PO did fiddle with the the choke cap like he did with the curb idle bracket. Maybe he tried to "repair" some other idle or cold start issue with the choke cap setting. Who knows.
    I bet itīs set too far. At least it is on the last notch far to the left. Will adjust by feel, too.

    Any suggestions? Start cold engine and turn the cap while itīs running and see what happens to the cam steps? Or try each notch per day?

  10. #10
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    1,114

    Default

    You don't really need to even start the engine to set the basics. Just a cold engine and a "not-hot" day.

    A is the arm that's attached to the cap spring.
    B is the lever, which is adjusted by C, the "high idle adjustment screw". C only adjusts the RPM of the high idle.

    As you press the throttle, lever B pivots DOWN. The idea of the mechanism is that the A prevents B from coming all the way back up.

    In the picture below, the choke cap/spring is adjusted almost 90° too much counterclockwise / up.



    Rotate A down, so it is just resting on the lever B with very slight pressure on the spring. Then move the throttle by hand. As you touch the throttle, you should be able to see arm A drop a bit, when B moves down and out of the way. Lever B should be then engaged on a notch on the A arm.
    Pic below: That's the "engaged" position viewed from the driver's side. There it is obvious how A prevent B from going back UP.



    Once you see how the A arm blocks B from coming back up, it should be pretty easy to tinker so it just grabs onto the first notch at the tip. You should also screw out the RPM screw to most the way out, since it might cause the lever B to get caught on the other notches and keep the high idle engaged.

    When you get the basics set, there are basically 2 adjustments:
    - Rotating the choke cap: counter-clockwise to shorten the duration of high idle, clockwise to increase duration. (you will still have to press the throttle to disengage choke, when it has warmed up a bit)
    - The screw adjusts the RPM of the high idle, I'd recommend starting low, since you probably won't be driving this in very cold weather.
    Attached Thumbnails Attached Thumbnails 20210611_123457.jpg   Page-287001.png  
    1985 Mercury Grand Marquis LS, "Maisa"
    2008 BMW 530d Touring, "Femma"

  11. #11
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default

    Thanks for the superb instructions. Thatīs what I missed in the manuals.
    I will do the reset an see if that helps.

    I drive the car in cold winter, too. Donīt want to miss this smooth ride Wifeīs modern Mercedes is a carriage compared to the Town Car. But I donī t need to commute to work - I can walk or use the bicycle, so I can spare the car anytime if things get worse. But if I need to drive somewhere I want to use the Town Car as often as possible. Get behind the wheel and you relax - no more stress. You take things more calm and it doesnīt matter how fast you get places anymore. I just love this.

  12. #12
    GMN Regular DerekTheGreat's Avatar
    Join Date
    Sep 2014
    Location
    Warren, MI
    Posts
    6,643

    Default

    Quote Originally Posted by Hillbillycat View Post
    ..But if I need to drive somewhere I want to use the Town Car as often as possible. Get behind the wheel and you relax - no more stress. You take things more calm and it doesnīt matter how fast you get places anymore. I just love this.
    This. When I first bought my Town Car, my interest in fast things began to decline.

    This info should be stickied, these issues with CFI crop up quite a bit and I think this could help more people in the future.
    1985 LTD Crown Victoria - SOLD
    1988 Town Car Signature - Current Party Barge

  13. #13
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    1,114

    Default

    Shit I drive a big block land yacht all year round if my commute would be short enough to walk. For now, I need to have atleast one car with reasonable fuel consumption.

    Hopefully with my MGM getting the carb swap treatment, it'll be the ol' reliable that I want it to be. Before I can truly relax behind a wheel, the car in question has to prove itself. Even how things have been, the MGM hasn't left me stranded. Once I get the running department sorted out, it ought to be just minty.

    My beemer is kinda meh in that department, I thought I'd get a good daily driver from it for several years, but it lacks character (as I kinda expected). It's as good as it can be, and definitely would serve me well. Sterile, cold, clean and kinda boring even though it couldn't be any better. That's german cars for ya.


    I would've done a way better job with the choke explanation, but my car is in storage and I couldn't get any photos and had to use what I had.
    1985 Mercury Grand Marquis LS, "Maisa"
    2008 BMW 530d Touring, "Femma"

  14. #14
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default

    No need for apologies. I think the explatnation is well enough. Had no time to do this yet. Right now the Town Car sits covered in snow outside. And I didnīt want to dive under the hood while your back getīs full of snow.
    I drive it year round, parallel to my 6.9 Diesel F250 truck and probably have less emissions than most other folks that are reliant to their modern cars.

    Miss the limited slip of my F250 on the Town Car though. Got stuck on my pals slope driveway in first snow. Winter tires are nine years old - probably should invest into a new set to improve traction. Plan for now is t pack a bag of kitty litter and a shovel. And do some practise to see how she behaves.

  15. #15
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    1,114

    Default

    How's the 6.9 in the german winter? A friend of mine has a '88 F250 schlong box 4x4 with the NA 7.3, she'll always start, but dang if it takes a while sometimes. In -35°C it took like 90 seconds of cycling plugs to get a single sputter out of it.
    1985 Mercury Grand Marquis LS, "Maisa"
    2008 BMW 530d Touring, "Femma"

  16. #16
    GMN Regular DerekTheGreat's Avatar
    Join Date
    Sep 2014
    Location
    Warren, MI
    Posts
    6,643

    Default

    ..Isn't that just when you hit 'em with the laughing gas? Everyone says not to use ether on diesels, but I've yet to see one blow up from being bottle fed on cold mornings... In Australia there was a brand of ether called "Start 'ya Bastard". LoL.. That's the brand I'd have bought every time because that's pretty much my attitude once an ICE won't cooperate.
    1985 LTD Crown Victoria - SOLD
    1988 Town Car Signature - Current Party Barge

  17. #17
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default

    No problems on the 6.9!
    She always starts, except for last year when I had burnt the plugs. I had converted to a manual push-button glow plug system when I had gotten thr truck and overlooked that the 6.9s run 6 volt glow plugs for a faster warmup. No problem if you use the stock glow plug controller since itīs on/off cycle rate is matched to the 6V plugs. I however had latched the pushbutton a tad too long and burnt them through. New set of plugs and problem solved.

    Mine is 4x4 and long box, too but Banks turbocharged. Got quite some pep although the injection pump and injectors are still the stock ones and probably at the end of their lifespan. New pump and injectors will do quite some improvement I bet but on a hefty price. As long as she goes and still pulls Iīll stick to the old pump.

    The LS rear and 4x4 along with BF Goodrich All-Terrain tires make it a good ride in winter. Even with empty bed. Off road on hunting trips as well as roads.
    Last edited by Hillbillycat; 12-09-2021 at 08:53 AM.

  18. #18
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default

    Did check on the cam and lever setting. It has no affect on the problem. Neither does setting back the throttle kicker bracket a bit. (Remember I had adjusted that for higher curb idle when the engine stalled during sudden stops in summer)

    The present high idle problem comes from lack of vaccum on the choke pulldown diaphragm. It does not retract until quite some time after the engine is hot. Then thereīs suddenly vacuum present. Same goes for vacuum on the throttle kicker.
    During the faulty high idle period you can hear an intermittent clicking, similar to what it sounds like when performing an KOEO test. I was not able to tell from where that came from. Neiter was I able to feel the clicking on the three solenoids on the driver side valve cover, EGR sensor, injectors or fuel pressure regulator with my fingers while that clicking was going on.

    Do you think this is from a fault in the EECIV "computer"? Keeping it stuck on "elapsed high idle" hence cutting off voltage to the solenoid that controls choke pulldown and throttle kicker vacuum?
    I know of lytic caps going bad over time in there but had not read about this issue.

  19. #19
    Lost and driftin' Arquemann's Avatar
    Join Date
    Jul 2019
    Location
    Finland
    Posts
    1,114

    Default

    So the choke pull-off doesn't function correctly, and it's causing the choke to stay on?
    1985 Mercury Grand Marquis LS, "Maisa"
    2008 BMW 530d Touring, "Femma"

  20. #20
    Member
    Join Date
    Apr 2021
    Location
    Germany
    Posts
    109

    Default

    Yes, exactly.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
GMN Approved Links!


www.rockauto.com www.adtr.net