Page 2 of 4 FirstFirst 1234 LastLast
Results 16 to 30 of 47

Thread: 2 Problems: Rough idle at cold start. Radiator fan not working when hot.

  1. #16
    Join Date
    Nov 2012
    Location
    Canton, GA
    Posts
    235
    Hello everyone,

    I finally started the 1991 SC for the first time since nearly overheating it. No white smoke out the exhaust and no steam coming out of the oil dipstick tube, so hopefully I'm ok for now.

    I bought a new radiator cap and a new Coolant Temperature Sender. I forgot to test the coolant temp sender before installing it so my gauge is probably not accurate. My temp gauge is on the M in NORM when my radiator hose is just getting warm (Supposedly when the car is at normal running temperature). So my gauge works, but reads way higher than I'm used to. I used a laser thermometer and the radiator was at 178 degrees Fahrenheit and the engine was at 182 degrees Fahrenheit when my needle was pointing at the M in NORM.

    After warming up the engine, I got a paperclip and connected it to the EEC TEST plug.

    I watched these YouTube videos and I connected my paperclip into the same connectors, but my Check Engine and/or Check Gauge light did not flash (I waited about 2-3 minutes each time before giving up). I removed and reinserted the paperclip about 3-4 times and left it in once while I started up the car for a Key On Engine Running Test, but it still didn't flash then either (to be fair, I didn't pump my brakes or turn my steering wheel like I was supposed to in the video). I know the car recognizes something is different because when there is no paperclip put into the EEC TEST, the car beeps when the key is on and the Shift light is on. However, when the paperclip is connected, the car DOES NOT beep and the shift light is off. In both cases the Check Gauge light is on and nothing is flashing.

    Here's the YouTube videos I watched. Let me know if there is something else I should try. Should I just buy the $29.99 OBD-1 Ford scanner tool from Autozone?

    KOER
    https://www.youtube.com/watch?v=nl2lqqS7vvE

    KOEO
    https://www.youtube.com/watch?v=-YYQKssOEOs

    Name:  IMG_6839.JPG
Views: 153
Size:  1.43 MBName:  IMG_6826.JPG
Views: 150
Size:  1.53 MBName:  IMG_6833.JPG
Views: 147
Size:  2.41 MB

  2. #17
    Join Date
    Dec 2007
    Location
    Salem OR
    Posts
    7,059
    About the temps. When the engine is 'just getting' warm Feel warmth in the upper hose, but can lay your hand on the radiator still), and the thermostat is open(ing), the temp wouldn't quite be near normal operating, and on the gauge would not be anywhere near M, I believe. The fan should come on before/at that point. If it's actually that hot and the fans are quiet, the fan circuit is suspect. What temp does the IR gun report at the coolant air bleed bolt? M would be right around 200~203 I think. If the gauge is mis-reporting (not sure yours is), that's another issue. I'd want to finish self-testing the IRCM/fan/ECT first.

    And just to note, there have been TSB's on mis-reading SC gauges - search here, just be wary of getting a mismatched sender from the aftermarket today. See comment #6 in this thread:
    http://www.sccoa.com/forums/showthre...795#post914795

    > Should I just buy the $29.99 OBD-1 Ford scanner tool from Autozone?

    Code reader for the win.

    Don't get me wrong, back in the day I was all over jumpering the self-test connector, but not since code readers became common and affordable to the public. I created this image back in 1982, which, funny enough, is still being circulated on the 'net today:


    I used that process to demonstrate to a Ford dealer that their $10k STAR tester was wrong when it said the ECU in my nearly new '85 Turbo Coupe was not stuck in limp mode. They brought in another STAR, re-tested, agreed w/me and fixed my 'bird.

    Are you sure you're using the VIP Self-Test connector and not the ARC test connector?

    ...but the code reader makes the process easier, more reliable and more comprehensive. They usually come with a guide, but the 'net has tons of info on the different tests that can be performed and what the codes mean. I like this list, which calls out SC-centric codes: http://www.njtacc.com/tech/eec_codes.html
    Last edited by KMT; 04-11-2019 at 03:59 PM.

  3. #18
    Join Date
    Nov 2012
    Location
    Canton, GA
    Posts
    235
    Thanks for your fast response.

    It occurred to me less than an hour after posting that I should try doing the same paperclip thing to my 1990 SC (to see if I knew what I was doing). My 1990 SC check engine light does come on and flash. I also heard the radiator fan kick on for 1 second (so I see now what you meant earlier). Im guessing my Check Engine light in my 1991 SC doesnt work and/or has a whole other electrical problem I knew nothing about. Im hoping its the former, because I suspect I could get away with just using a scanner/reader instead of replacing the Check Engine bulb.

    I know a guy who said he had something for OBD-1 (for Fords) that hed give me in a couple days. Ill try using his and see if my 1991 can flash some codes.

    I wished I knew about this OBD-1 stuff sooner. I get a little trigger-happy with the parts canon

  4. #19
    Join Date
    Dec 2007
    Location
    Salem OR
    Posts
    7,059
    Quote Originally Posted by Rick_Leuce View Post
    My 1990 SC check engine light does come on and flash. I also heard the radiator fan kick on for 1 second (so I see now what you meant earlier).
    Nice deduction, it always helps to confirm your tools and process.

    >Im guessing my Check Engine light in my 1991 SC doesnt work [clip] ...instead of replacing the Check Engine bulb.
    Yes, sounds like something's up. The IRCM has a power relay for the ECU, but if that's borked, I'd not expect the car to run, so...

    See this link, long post by jrichker, about 1/2 way down 'Computer will not go into diagnostic mode': https://www.stangnet.com/mustang-for...o-test.709184/

    - explains how to test that circuit.

    I'd at least do this much...
    How to test the wiring:
    With the power off, measure the resistance between the computer test ground (black/white wire) on the self test connector and battery ground. You should see less than 1.5 ohms.


    The whole purpose of this exercise is to validate the IRCM and the fan circuits. There are ways to power the relays directly at the IRCM, so while the inability to self test may point to related issues, etc., don't let a self-test be a show stopper for that process.
    Last edited by KMT; 04-12-2019 at 12:39 AM.

  5. #20
    Join Date
    Nov 2012
    Location
    Canton, GA
    Posts
    235
    Quote Originally Posted by KMT View Post
    And just to note, there have been TSB's on mis-reading SC gauges - search here, just be wary of getting a mismatched sender from the aftermarket today. See comment #6 in this thread:
    http://www.sccoa.com/forums/showthre...795#post914795

    Don't get me wrong, back in the day I was all over jumpering the self-test connector, but not since code readers became common and affordable to the public. I created this image back in 1982, which, funny enough, is still being circulated on the 'net today:


    Are you sure you're using the VIP Self-Test connector and not the ARC test connector?
    Thank you so much for this info. My 1990 SC was flashing 67,67, 11111 (I did it 3 times and it was consistent each time).
    67 can mean Clutch Switch Circuit Failed (SC only). Its a 5-speed, so this is possible.
    67 can ALSO mean Neutral Drive Switch Circuit Open. Im assuming that because my car flashes it twice, I could have both of these issues.

    Im guessing 11111 is a combo of 11 and 111. Both 11 and 111 mean System Pass according to the sheet you provided.

    I guess its good Im learning this stuff because it helps me with both cars.

    The first link you sent me for the SCCOA thread isnt working, could you send it again?

    I dont know for sure if I used the VIP Self-Test connector or the ARC test connector. I just used the two plugs that were included in the EEC TEST cover.

    I really believe that the Check Engine light does not work in the 1991. In fact, other lights might not be working based on the photo I took in the 1990 today. (Im using iPhone right now, so hopefully it comes out right). Either way, Im definately using something other than a paperclip going forward.

    Thanks again for your help. This OBD-1 stuff is all new to me (even though Ive owned my 1991 SC for over 6 years).
    Attached Images Attached Images  

  6. #21
    Join Date
    Dec 2007
    Location
    Salem OR
    Posts
    7,059
    Quote Originally Posted by Rick_Leuce View Post
    ...really believe that the Check Engine light does not work in the 1991
    Right, I lost track between 'gage' and 'engine' and now that both the '90 and the '91 are being discussed I'll need to pay better attention. I'd want to know sooner than later if it's just a borked bulb in the '91. If you need tips on a cluster pull, as always, speak up or search.

    The first link you sent me for the SCCOA thread isn’t working, could you send it again?
    Sorry, missed the double check on that one - try this...http://www.sccoa.com/forums/showthre...795#post914795

    >I’m guessing 11111 is a combo of 11 and 11
    Don't guess. To an SC, guesses smell like fear chucking your wallet down an open manhole with a big grin on it's face. Your SCs won't respect you if they smell fear. Get a code reader, pls., or... maybe whomever suggested the clip method can help you decode flashes, I'm a bit too rusty on that process

    Note this link for good info on both manual and code reader code pulls: http://www.amopower.com/eec-iv.htm
    Last edited by KMT; 04-12-2019 at 11:11 AM. Reason: added code reader process link

  7. #22
    Join Date
    Feb 2003
    Location
    NE PA
    Posts
    498

    6

    Is the fan on your 91 hooked up correctly? When doing the test the fan should come on just like your 90. As for you 90, IIRC the 111 is engine designation and the 11 is pass and should be 2 digit codes as opposed to 3 digit codes for your 91.

  8. #23
    Join Date
    Nov 2012
    Location
    Canton, GA
    Posts
    235
    Quote Originally Posted by 99GSXR750 View Post
    Is the fan on your 91 hooked up correctly? When doing the test the fan should come on just like your 90. As for you 90, IIRC the 111 is engine designation and the 11 is pass and should be 2 digit codes as opposed to 3 digit codes for your 91.
    The fan in the 1991 is not hooked up properly. Its still plugged into the Autozone temp sensor/relay kit that determines when the fan comes on all by itself. I’ll set the car back to running off the IRCM relay soon. My 1991 Tbird got put to the back burner as we worked on other projects, but it should get more attention soon.

    Im only guessing about the 11 and 111 code. I only know it flashed “1” 5 times after “67”
    One of those flashes might have meant something else, like the “test is over” or something. I wasnt expecting the 1990 to flash any really bad codes. After a Google search, my “67” could have been caused by the car being in 1st gear while doing the test. I’ll check again in neutral this weekend. I’ll even record it in case the spacing between the “1’s” is long or short.

    There was a reason we used the crappy Autozone kit in the 1991 but we couldn’t determine why my IRCM relay wouldnt turn the fan on when the car got hot and wouldnt make the fan come on when the AC was on. Im retroactively wondering if the IRCM relay might have been ok but the fan motor was bad. I think we put the stupid Autozone kit in BEFORE swapping the fan motor. Now that I know the car has OBD-1 and that I can flash codes, I cant wait to pull that stupid relay out and just use the IRCM relay.

    Hopefully this weekend my dad and I will hook up the fan normally so I can troubleshoot more easily. I think I lost my original Ford IRCM relay for the 1991 SC (I only have 2 Chinese ones) should I borrow the one from my 1990 and use it in the 1991 as a control test?

  9. #24
    Join Date
    Nov 2012
    Location
    Canton, GA
    Posts
    235
    On the 1991 Thunderbird, I plugged the fan back into the original plug. When I do the paperclip thing with the OBD-1, the radiator fan does come on for a fraction of a second. However the fan didnt turn on when my radiator reached 190-195 degrees Fahrenheit.

    While at this point, I stuck a digital volt meter into the OBD-1 plug and its voltage did bounce after I turned the key. The volt meter couldnt reset back to zero fast enough for me to accurately count flashes, but I figure that my check engine light is not working and that I could read the flashes by using an indicator light or OBD-1 reader.

    My dad told me the aftermarket fan IS a 2-speed. So were thinking of wiring it up so that the Low speed comes on when the key is on and the Hi speed comes on when the radiator hits 180 degrees Fahrenheit.

    Im in Charlotte NC right now for the Mustang 55th anniversary car show. Ill get a proper tool for reading codes when I get back home.

    I really appreciate all the feedback and advice youve given me. You guys are great

  10. #25
    Join Date
    Jul 2004
    Location
    Hamilton NJ
    Posts
    2,088
    The idle problem when cold could be the iac or tps sensor, and the fan not coming on could be the ECT coolant sensor in the intake manifold by the oil fill cap..

    Those were my fix for my 90... not saying it will be yours but ect sensor is cheap to buy at autozone or advanced auto
    Tom Downs-member#2752
    MPX'd 90 SC Auto~bought Feb. 2012
    RIP MOM!!! I will always miss and think about you 4Ever! 1940-2018
    RIP Rexy boy!!!! Miss my dog 2006-2018
    http://www.sccoa.com/forums/garage_v...vehicle&id=424

  11. #26
    Join Date
    Jul 2005
    Location
    Clarksville, TN
    Posts
    1,846
    Rick,
    As it was shown earlier the fan strategies for the SC have the fans coming on at a rather high temp and with the 192 degree thermostat, it is not uncommon for the gauge to show past the M and the fan not come on until 1/2 way between the M and the H. Remember it has to get 30 degrees hotter than the thermostat opening temp before the low speed fan should be turning on. You can sort of figure between the o and R is say the 192 for thermostat to open, then figure in another 30 degree before the low speed fan kicks in. These gauges are notoriously un-calibrated and can be way off.

    I didi notice in some of your pics there where wire T connectors on some of the wires coming out of the IRCM I am only guessing these are for the aftermarket temp sensor kit. I saw earlier that someone said if the high speed fan kicks on the low speed fan stays on too, but this I think is incorrect. You either get one fan speed or the other, the circuit not being used gets turned off by the IRCM.

    One thing you can do is to let the car warm up until it gets to the M or a little past and measure the voltage on the low speed fan circuit at the fan to see if it getting the 12V on that connector. Of course it would all have to be back to the factory connections as other s have mentioned. I agree with Tom and others that changing out the ECT on the intake manifold with the 3 wires may help fix the issue also. if the ECU isn't seeing a high enough temp reading from the intake ECT sensor it will never turn the circuit on inside the IRCM. Make sense?

    Also keep in mind that the temp sensor for the gauge just gives the driver a visual to look at but has nothing to do with turning the fans on or off, so it is really not doing much but freaking you out! LOL The important sensor is the one on the intake manifold.

    Keep at it, lots of good people here to help you figure it out. Oh and getting the code reader is the way to go. I have done both and really like the simplicity of the OBD1 tester for our cars, especially with it having beeps.

    Like others have mentioned when you either jumper the test connector or use the OBD1 scan tool, the fans should kick in as soon as the KOEO test starts, if not I would start there by checking voltage at the fan connector itself.

    Good luck.
    Smitty
    Venetian Blue 1995 5 Spd...............No ET
    Orange Crush Pearl 1995 Auto SC........TBD
    506.30 rwhp, 545.37tq
    Garage:http://www.sccoa.com/forums/garage_v..._vehicle&id=13

  12. #27
    Join Date
    Dec 2007
    Location
    Salem OR
    Posts
    7,059
    Quote Originally Posted by Quik95SC View Post
    I saw earlier that someone said if the high speed fan kicks on the low speed fan stays on too, but this I think is incorrect. You either get one fan speed or the other, the circuit not being used gets turned off by the IRCM.
    Looks like both are hot when HI is energized to me: https://youtu.be/czr4g0dnYvE -- EVTM, tho, says, "Once the fan speed is determined, the EEC module energizes the High Speed Fan Relay or the Low Speed Fan Relay to allow application of battery voltage through Fusible Link B to the correct windings of the Coolant Fan Motor."

    Ken
    Last edited by KMT; 05-07-2019 at 05:33 PM.

  13. #28
    Join Date
    Apr 2002
    Location
    English, IN
    Posts
    4,444
    Sorry if I missed it, but did you try replacing the ECT sensor? Not the temperature sending unit (for the gauge)...the one that the EEC uses for cold-start enrichment tables and electric fan turn-on settings.

    Although you should have a check engine light, a bad ECT cold be the culprit for both poor cold startups/warmups (since fueling is scaled based on engine coolant temperature, among other things) and improper fan operation.

    The ECT is the 3 or 4 wire sensor that screws into the intake manifold, just behind the DIS module.
    Matt Haub
    Shootouts: '09 SS 1st | '10 Mod1 2nd | '11 Bracket 3rd | '12 Bracket 1st | 2013 | '14 Bracket 3rd | 2015 | '16 Bracket 1st & Mod2 2nd | 2017 |
    Black '89 5spd - 281K miles, MPx, E85, Alky-Inj RWHP: ? RWTQ: ? Best 1/4mi:12.521, MPH:107.23mph
    35th Anniversary Auto 46k miles | Red '93 Auto 186k miles
    My Garage

  14. #29
    Join Date
    Nov 2012
    Location
    Canton, GA
    Posts
    235
    Quote Originally Posted by DrFishbone View Post
    Sorry if I missed it, but did you try replacing the ECT sensor? Not the temperature sending unit (for the gauge)...the one that the EEC uses for cold-start enrichment tables and electric fan turn-on settings.

    Although you should have a check engine light, a bad ECT cold be the culprit for both poor cold startups/warmups (since fueling is scaled based on engine coolant temperature, among other things) and improper fan operation.

    The ECT is the 3 or 4 wire sensor that screws into the intake manifold, just behind the DIS module.
    Quote Originally Posted by DrFishbone View Post
    Sorry if I missed it, but did you try replacing the ECT sensor? Not the temperature sending unit (for the gauge)...the one that the EEC uses for cold-start enrichment tables and electric fan turn-on settings.

    Although you should have a check engine light, a bad ECT cold be the culprit for both poor cold startups/warmups (since fueling is scaled based on engine coolant temperature, among other things) and improper fan operation.

    The ECT is the 3 or 4 wire sensor that screws into the intake manifold, just behind the DIS module.
    I have good and bad news:

    Good news: My friend and I ran some wiring and connected an adjustable thermostat to a relay to make my fan come on. I can set it to approximately whatever I want, so I used a laser thermometer and set my fan to come on once the car hit 195 degrees F. I have tested it multiple times and my fan RELIABLY comes on at that temp. I have an indicator light in my car for when the fan is on, so Ill never have to wonder again.
    The UPS Store, 1353 Riverstone Pkwy Ste 120, Canton, GA 30114
    I replaced my ECT sensor and the car started smoothly and immediately idled fine without having to rev the engine. It now idles just as quietly as my 1990 SC daily driver, so I was very happy.

    Bad news: Right as I was getting in my car to turn it off, my friend yelled white smoke coming out your exhaust! and I turned it off immediately I walked behind my car immediately and saw faint white-ish smoke lingering in the air. They said it started suddenly for no reason. Based on the fact my car has almost overheated 5-6 times since Ive owned it (with coolant spewing out of my radiator) I think its possible the head gaskets blew. Im especially suspicious because the coolant level in my reservoir did not noticably rise after the radiator was hot. I also had to top off my coolant reservoir last week when it was too low to tell what level it was at.

  15. #30
    Join Date
    Dec 2007
    Location
    Salem OR
    Posts
    7,059
    So this is the 91, then...been after you since 4.4.19 to replace the ECT...better late than never

    Quote Originally Posted by Rick_Leuce View Post
    set my fan to come on once the car hit 195 degrees F. I have tested it multiple times and my fan RELIABLY comes on at that temp.
    About that...too low, I think. You'll risk fighting the thermostat, running too cool, especially at speed when the fan is usually off, making it run rich, etc.

    As noted up thread, the stock fan speed strategy is as follows:
    Lo speed on: 222
    Lo speed off: 214
    -=-
    Hi speed on: 228
    Hi speed off: 220


    About the white smoke...remind me, did you get a combustion test kit to check for gases in the expansion tank yet? AZ rents them, I think. Anything but clean oil on the dipstick? Any foam inside the oil filler cap? Milkshake in the expansion tank? Upper hose tight but not bulging when the engine is at temp?
    Last edited by KMT; 06-18-2019 at 12:18 AM.

Similar Threads

  1. Rough Idle on Cold Start Up...
    By darkstar_one in forum Technical Forum
    Replies: 0
    Last Post: 01-28-2007, 01:53 PM
  2. Rough idling during cold starts
    By mn12freak in forum Technical Forum
    Replies: 10
    Last Post: 07-09-2004, 11:47 PM
  3. Rough Idle at Times...stalling on cold start
    By 1fastscinpa in forum Technical Forum
    Replies: 0
    Last Post: 02-07-2004, 02:48 PM
  4. Radiator fan not working
    By blown11 in forum Technical Forum
    Replies: 1
    Last Post: 05-04-2003, 02:16 PM
  5. Problem: Rough Idle at Startup
    By PSYANIDE sc in forum Super Coupe Club of Northern California
    Replies: 6
    Last Post: 05-30-2002, 11:16 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •