Car runs badly in cold weather

craniumcranium Member Posts: 40
edited March 2014 in Buick
Ok, I've got a 1989 Buick Century, that I will be using for a winter car this year. I drove it for almost the whole month in August, and 2-3 times per week in September, to make sure all the bugs were out before the snow flies, and my other car goes in the garage for hibernation. Through out this test period, I ran into few problems, which I have now sorted. But, since the cold weather is upon us, it has started to run real lumpy, and stall.

It starts fine, and drives fine, but once I come to a stop, or I take my foot off the gas, it stalls. Once stalled, It starts immediatly, but also dies immediately. It has new plugs, wires, and fuel filter as of 12/01. It sounds as though it is mis-firing but I have no knowledge as to prove this. It has a distrubitorless ignition, so I cannot replace the cap and rotor. This system is foreign to me, and I have no idea how to adjust it.

I don't understand why this only happens when it is cold. (the weather, not the engine) This only happens when the temp is in the low 50's or less..

Please help


  • craniumcranium Member Posts: 40
    While I was under the hood this weekend, I thought that maybe it wasn't getting air (old air filter), so I took it off, and like usual it stalled (no difference with or without filter), but when it stalled, it coughed!! I acutally saw smoke, or something come out of the throttle body!

    Is this a lead as to what the problem might be?
  • lancerfixerlancerfixer Member Posts: 1,308
    Have you tried removing and cleaning out your throttle body? I did this exact procedure on my '89 Volvo this past weekend, for exactly the same reason; it would stall after running at operating temp for a while when I pushed in the clutch to come to a stop. I found some instructions online (Volvo-specific, sorry,) on how to clean the throttle body. It was pretty gummed up; I removed it and discovered that one of the vacuum lines was clogged on the TB end by this gunk. Some carb cleaner and a rag, and voila. I put some new spark plugs in for good measure, and the car runs perfectly now. Try it out.
  • alcanalcan Member Posts: 2,550
    Have the coolant temp sensor checked.
  • craniumcranium Member Posts: 40
    Yesterday, I limped it over to Autozone (local chain) and they checked the code (for free, got to love that), and told me it is code 26, and 27. they printed it out, and I read what it said, but unfortunatley, I don't have the knowledge to decifer it. It tells me how to test all these wires off the transmissioin, and putting the car on blocks, and get it running, and waiting for the car to shift into final gear, and then I need to test some wires. At the bottom of the page, (for both codes), it tells me that I need some part that costs $85. (Ignition control module?)

    The guy at autozone told me that I may beable to just disengage the overdrive, by unplugging some wire, and this might cure the problem.

    Also, while under the hood on sunday, I thought maybe a vaccum leak, I used wd40, and sprayed like hell. No difference.

    Looks like I'm off to get the haynes manual at the library today at lunch.

    Coolant sensor? Where is it, and how do I check it?

    What I still don't understand, is if it's electrical, why does this only happen in cold weather?

    Thanks again for your help.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Don't discount the possibility of more than one problem either. However, sounds like the temp sensor is a more productive avenue for diagnosis at this point rather than the controller for the torque converter lock up. But I' look at both.
  • craniumcranium Member Posts: 40
    leaning toward a bad torque converter lock up solenoid/switch. But looking over the records of this car, this was replaced in August 2001.

    I've done searches over the web, and it seems that others with the same symptoms have cured it with a new solenoid. If it was replaced 14 months ago, could it have gone bad again?
  • craniumcranium Member Posts: 40
    and this morning. It seems as though it only runs poorly when cold. Once it's warm, it runs like normal. Last night, while cold, I unpluged the Mass Air Flow, and took it for a test drive. No change. I then hooked that back up, and unplugged the Torque converter Lock up switch (square plug at front of tranny), no change. The engine was still cold at this point (late last night).

    This morning, I did the same, and got the same results. But of course it warmed up much quicker, and as soon as my temp rose from cold to normal, it was running fine.

    I'm confused as hell now. My codes 26, and 27 showed it was a tranny problem, but now I'm thinking it might be the ignition control module, or a coil, or the ECM.

    Or, could it be the temp sensor? I guess this could cause havic with the tranny.

    Also, when I got the codes read at Autozone, they gave me directions on how to pin point the problem. It told me to check some wires coming from the ECM, and Diagostic Connector (aldl). I have no idea where these are, and which are wire's "f6", or "d", or "A"

    h, BTW, I checked the Tranny fluid, and it's clean, and full. Everything "looks normal"

    Could someone help? Pleeeease??
  • swschradswschrad Member Posts: 2,171
    what I'm thinking is that if a warm engine starts on a cold morning and runs decently, that seriously implicates the coolant temp sensor. if it still acts like crud, another thing to think about is the air intake temp sensor if equipped. if you have an outside temp display on the car, and it's halfway near normal, that's probably not an issue, I think they all piggyback off the same sensor.

    the magnetic engine heater block is completely satisfactory for this quick test... heat the block up an hour or so and if it feels warm on touch, see how things work.
  • craniumcranium Member Posts: 40
    Thanks for the help. I have no way to borrow a heater. There is no external thermometer on this car. I'm not sure if it has an air intake temp sensor. I'll take a look at the books tonight, and will let you know. Where is the coolat temp sensor on this car? in the head? next to the PVC filter?

    How 'bout an Mass Air Flow Sensor? Some have told me it could be this, but I am unable to take it off the throttle body, b/c the screws are stripping. I'll put some liquid wrench on them tonight..

    Thanks for the help so far! I haven't given up just yet!
  • jgmilbergjgmilberg Member Posts: 872
    The temp sensor is in usually found in the cylinder head, or intake manifold. It goes into the water jacket, so if you were thinking of flushing out the cooling system now would be the time, and a new thermostat never hurts if you have to empty the cooling system anyway. The coolant temp sensor tells the computer how much fuel to add to the mix for the cold engine, if that sensor takes a dump nothing works right and fuel economy will drop considerably. Usually it will dump more fuel in when cold, so when you come to a stop you have to much fuel going into the engine causing it to stall.

    When the car stalls and you re-start does it stay running until you put it in gear? If that is the problem, the lock up solenoid might be trashed again.

    Now that you have pulled the codes try clearing the computer memory and see if anything comes back. Just disconnect the battery for 5 minutes. The codes might be left over from when the solenoid was bad. Is the Service Engine Soon light on?
  • craniumcranium Member Posts: 40
    I've been told it is the Mass air Flow sensor, the PCV Valve, and now the temp sensor. And, I'm still not sure what it is. The PCV valve, and temp sensor are both cheap, so I may just replace them for kicks. (if I can locate the temp sensor. I think it's next to the PCV in the head.

    jgmilberg- The car does not run well when in park, reverse, neutral, or drive. But this only happens when the engine, and outside temp is cold.

    The engine light only comes on when it stalls, then goes out. when I unplugged the Mass Air Flow sensor, and went for a drive, only then the the check engine light come on.

    I'm still working on this, but let me ask you this? What good is the computer, if it gives you false readings?? That kills me!!!.. UGGHHH!!!

    Thanks again everyone. I may not beable to get to this till friday, but will definitely keep eveyone updated on my progress. Also, if you have more ideas, keep um coming!!!
  • craniumcranium Member Posts: 40
    I got to it yesterday, after the trick or treater's were done. I pulled the PCV valve (what a pain), and it was fine. I shook it and it rattled, so it obviously wasn't stuck. I gave it a shot of throttle cleaner for good measure. My next step is to check the coolant temp sensor. It's only $8, so I'm off to buy one tonight. I do have a question though. It's located in the head, just above the water pump on the passenger side. I looked, and I see 2 that are very similar. Both mounted horizontially in the head. One has a single green wire on it, and another has 2 wires, (black, and yellow). Which is the temp sensor? Is there a way I can check to see if it's bad before replacement?

    Thanks again!
  • tbonertboner Member Posts: 402
    I think you said you had a gauge, right. So one of them is probably for the gauge, and the other for the computer. As far as which is which, I dunno.

    I suppose you could warm it up and then pull the wires one of them. If the gauge stops working, you know you got the gauge. If you set a CEL, then you know you got the one that feeds the PCM.

    Or just call the parts store and ask them if one wire or two goes to the engine coolant temp sensor.

    I've subscribed to for my 87 LeSabre. The wiring diagrams in there are far better than what I've found in Chiltons or Haynes manuals.


  • alcanalcan Member Posts: 2,550
    The 2 wire unit is the coolant temp sensor. Should also have a rubber atmospheric seal on the connector, like all computer sensors have. The single wire is the sending unit for the light or gauge.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Hey, I've been reading that on a 2000 Impala the torque converter lock up is temperature controlled to prevent "stalling when cold". So maybe I have to re-think this problem after all.
  • vidtechvidtech Member Posts: 212
    sounds to me like your lost and just guessing now.take it to someone who knows what they're may spend more just guessing than taking it to a professional.eventually,after replacing a half dozen parts you may get lucky.
  • jgmilbergjgmilberg Member Posts: 872
    You have to change out that sensor fast, have the new one ready to stick in and pull one and jam the other in so you don't lose a lot of coolant.

    Now as far as the coolant goes make sure NOT to mix them up. If you have the green stuff only use the green stuff, and the same goes for the dex cool pink stuff. The two are not compatible and will cause problems later.
  • craniumcranium Member Posts: 40
    got to it again today. I finally got the Mass Air Flow sensor off. When I took it out, one of the springs (the shorter) was dirty. Both were unbroken. I shot the dirty one with some carb cleaner, and brushed it off with a small (model) paint brush. They both cleaned up nicely, and I re-installed.

    I started it, and the same thing happened. It would run really rough, and if I gave it any gas at all, it would stall, and I would hear a cough out the throttle body. I started to pull out of the garage, and it continued to stall whenever any gas was given. I let it warm up, and it drove better, but it would still stall once coming to idle. This time, it seems as though it is not engine temp related. While I was out on the road (with the engine at normal temp), it would stall at idle, and when I would re-start it, it would sometimes idle very high, (3500 is a guess). It would then idle down, and hesitate, and almost stall, but catch itself. and run rough.

    Now what? I went to the scappers, and picked up 3 ignition coils, and the ignition control module for $45. I'll try swapping some of these parts out tomorrow. Is there a way to test the coil packs, and the module to make sure they are good?

    Now I'm figuring, it's getting gas, and air, but not fire.

    Anyone else have any ideas? Please remember, I still don't want to put any $$ in this thing unless necessary. I'll drive it for the winter, then trade it in, along with the wife's car for a (gulp), minivan.
    Thanks again.
  • alcanalcan Member Posts: 2,550
    No offence meant, but by the time it's fixed by the throw parts at it method you'll probably end spending more than what it would have cost to have it repaired professionally. Time to bite the bullet and have a competent tech hook up a scanner to monitor the data stream. That should pinpoint the problem in short order.
  • craniumcranium Member Posts: 40
    This has become more of a quest than anything. So far, I have only spent $45 on this car, and, I haven't even intalled these parts yet. Hopefully they will cure the problem. $45 is what? 1 hour labor at a "cheap" garage? The problem with this car is, the wife does not want it, and I do.
    So to keep it, I must spend minimum funds to get it running. This is more for me to fix, than to give to a mechanic to fix. Besides, all a mechanic is going to do, it to run the diagnositic codes, and it's going to come up with the Codes 26, and 27 above, which we know are for the Tranny. But we also know that the tranny is not at fault here.

    Lets get back to the problem. This car ran great in august in warm weather. In september, when the weather was below 50 or so, it stalls in park, neutral, drive, reverse. It will only stall in these gears while at idle. It runs fantastic when driving, only when coming to a stop does it stall. Immediatly after it stalls, it will let out a small cough.

    I have recently replaced the battery (july), plugs, wires, and one ignition coil (dec, 01), new TCC solenoid (August 01). Also looking through the reciepts, it looks like an ECM was also replaced in the past (years ago). Now, When taken to our "mechanic" (I use this term loosely), he said that he thought it might be another ignition coil, or the Ignition control module (plate the 3 coils sit on), that might be the problem. This is why I purchased the 3 coils, and the ICM, from the junk yard.

    Why does this only happen when cold? Could it be the coils or the ICM?

    Thanks again guys..
  • craniumcranium Member Posts: 40
    You haven't given up on me have you?
  • jgmilbergjgmilberg Member Posts: 872
    It still say it's a cheap thing to swap out, so I would change the coolant temp sensor.

    The ICM might be to blame for the cold weather probs. The board does not expand at the same rate as the solder joints and when it is cold the board might pull away from the board causing a intermittent connection. After the board heats up it creates a good solid connection and away you go.

    When you replace the ICM make sure that if it has the sticky white grease on it that you put more grease on it before installing the new/used one. That grease helps transfer heat more efficiently, and w/o the grease the new unit will cook itself in short order.

    Just a word of advice, if you really want to keep the car till spring take it to a shop and have it diagnosed. Disconnect the battery just before you take the car in to clear the codes, and they can't come up with that as an explanation. Most dealers charge around $90/hr and it usually only takes 1 hour to diagnose, then you can do the repair yourself. There is a lot to say for a shop with a scope and computer.
  • craniumcranium Member Posts: 40
    I replaced the 3 igniton coils, and the Ignition Control Module (ICM-the plate the ignition coils sit on), and everything seems to be working as normal. The weather has been warm this weekend though, so I'll be testing it as the weather gets colder this week. I drove it to work this morning, and the temp was 53, so far, so good. Thanks for all the help. I think I've got this problem licked. I'll be sure to post if I have more problems.

    Thanks again everyone!
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